Met Reader Manual

User Manual:

Open the PDF directly: View PDF .
Page Count: 42

MetReader: Documentation and User’s Guide

Hans F. Schwaiger

June 26, 2018

1 Introduction

MetReader is a library written in fortran 90 that provides an interface to numerical weather

prediction (NWP) data, or other forms of meteorological data, such as radiosonde or other

1-D data.

This library was originally written as a component of the USGS volcanic ash transport

and dispersion model, Ash3d. However, since it is useful for programs other than Ash3d, this

interface to NWP ﬁles is provided as a separate repository that can either be compiled as a

library or simply compiled directly with other source code.

NWP data are generally made available by agencies (NCEP, NOAA, NASA, etc.) in

a variety of formats (NetCDF, GRIB1, GRIB2, ASCII); each product having its own data

structure, naming convention, units, etc. This library isolates the calling program from the

peculiarities of interfacing with a particular NWP product. Data can be returned to the

calling program on the native grid of the NWP product, or on any grid needed by the calling

program. Projection and interpolation of NWP data to the required grid, along with any

rotation of velocity vectors to grid-relative, is calculated internally by MetReader.

2 Installation

This library requires two additional libraries made available on GitHub and USGS GitLab:

•HoursSince

This is a library that takes a date and time, and calculates the number of hours since

January 1, 1900 (or any artibrary base year).

(https://github.com/hschwaiger-usgs/HoursSince)

•projection

This is a library that calculates commonly-used projected coordinates.

(https://github.com/hschwaiger-usgs/projection)

These libraries are installed by default into /opt/USGS. If they are installed elsewhere,

then you will need to edit the makeﬁle to point to your installation. Additionally, the default

makeﬁle will build MetReader with both NetCDF and GRIB2 enabled. If either of these

libraries are unavailable on your system, you can deactivate those options by setting the

corresponding ﬂags to Fin the makeﬁle. On a RHEL/CentOS system, you can install the

data format libraries by typing

sudo yum install netcdf netcdf-devel grib_api grib_api-devel

or for Ubuntu

sudo apt-get install libnetcdf* libgrib-api*

To compile MetReader as a library, simple type:

make all

This will build the requested components of the library. If GRIB2 is enabled, this will also

build the GRIB2 indexer, gen GRIB2 index. This is a tool that generates an index ﬁle of the

GRIB records which speeds access time to individual records substantially.

To install the library, module ﬁles and tools, edit the INSTALLDIR variable of the makeﬁle

(the default is /opt/USGS) and type:

make install

This will also install scripts that can be used to download the 0.5 degree GFS forecast ﬁles

and the NCEP 2.5-degree Reannalysis ﬁles.

You will need to have write permission in ${INSTALLDIR}or install as root. Assuming

the libraries projection and hourssince are installed in the default location, installation

will result in the following directory structure:

/opt/USGS

|-- bin

| |-- autorun_scripts

| | |-- autorun_gfs0.5deg.sh

| | |-- autorun_NCEP_50YearReanalysis.sh

| | |-- convert_gfs0.5deg.sh

| | |-- get_gfs0.5deg.sh

| | |-- get_NCEP_50YearReanalysis.sh

| | ‘-- grib2nc.sh

| |-- gen_GRIB2_index

| |-- HoursSince1900

| |-- ncMet_check

| |-- ncMetSonde

| |-- ncMetTraj_B

| |-- ncMetTraj_F

| ‘-- yyyymmddhh_since_1900

|-- include

| |-- metreader.mod

| ‘-- projection.mod

‘-- lib

|-- libhourssince.a

|-- libMetReader.a

‘-- libprojection.a

3 Usage

MetReader can read a variety of input data formats (1-D, 3-D, ASCII, NetCDF, GRIB2)

and provide access to the meteorological data on either the native grid of the NWP data, or

interpolated onto a ﬁner regular grid. Before the meterological data can be accessible, several

preliminary steps must ﬁrst be completed.

3.1 Preliminary meta-data

The calling program needs to prepare several parameters that deﬁne the type of meteorological

data to be read.

•iw :: windﬁle class (the distinction between 3 adn 4 will be obselete soon)

–1 : 1-D wind sounding

–2 : 3-D grid is read from a ASCII ﬁle

–3 : single, multistep 3-D dataﬁle

–4 : multiple 3-D dataﬁles

–5 : special case for NCEP 50-year reanalysis and NOAA reanalysis

•iwf :: windﬁle format number (linked to speciﬁc product in Table 8.2 of Appendix 8.2)

•igrid :: NCEP Grid ID

•idf :: Data ﬁle format code (ASCII, NetCDF, GRIB, etc)

–1 : ASCII

–2 : NetCDF

–3 : GRIB Edition 2

–4 : GRIB Edition 1 (Not yet implemented; used by NARR and NOAA-CIRES)

•iwfiles :: number of windﬁles to be read

•SimStartHour :: The starting time needed given as hours since 1900-01-01 00:00Z

This can alternatively be given as hours since a diﬀerent base year as described below.

•SimDuration :: duration needed in hours

Additionally, there are several other parameters that could be set, if needed.

•MR BaseYear :: The default value for this is 1900, but must be reassigned by the calling

program if the NWP ﬁles to be read contain data prior to 1900.

•MR useLeap :: The default is .true. but can be set to .false. if the NWP ﬁles use a

calendar without leap years (e.g. some paleoclimate CAM ﬁles)

•MR iHeightHandler :: This code deﬁnes how MetReader behaves when values at alti-

tudes above those available in the NWP ﬁles are requested. Default value is 2.

–1 : Stop the program

–2 : Return wind values equal to the value at the highest available node; tempera-

ture values remain constant from 11-20 km, then increase by 2◦C/km.

•MR iwf template :: This is the ﬁle name of the template for the custom NetCDF ﬁles

described in section 5. This is only required to be set if iwf=0. Currently, the custom

windﬁle speciﬁcation is only implemented for idf=2 (NetCDF).

•call MR Reset Memory :: If MetReader had been initialized and used for one set of

NWP ﬁles, but later during the execution of the calling program, a subsequent set of

NWP ﬁles is needed, this subroutine can be called to free all allocated memory.

Step 1: The space needed for storing the NWP ﬁle meta-data must be allocated.

call MR_Allocate_FullMetFileList(iw,iwf,igrid,idf,iwfiles)

This allocates the variable MR windfiles(1:MR iwindfiles).

Step 2: The calling program must now ﬁll the list of ﬁle names MR windfiles() with each

name not exceeding 130 characters in length. For the special cases for the NCEP/NCAR

Reanalysis 1 or the NOAA-CIRES 20th Century Reanalysis (iwf=25 or 27), MetReader

expects a speciﬁc structure to the directory holding the NWP ﬁles. For these reanalysis

product, the list of ﬁles is only one string (iwfiles=1) with the ‘ﬁle’ given as the root

directory to the NWP ﬁles. For example, for the NCEP/NCAR Reanalysis 1:

iwfiles = 1

MR_windfiles(1) = ‘/data/WindFiles/NCEP’

where the ﬁles are stored as follows:

/data/WindFiles/NCEP

|-- 2016

| |-- air.2016.nc

| |-- hgt.2016.nc

| |-- omega.2016.nc

| |-- shum.2016.nc

| |-- uwnd.2016.nc

| ‘-- vwnd.2016.nc

|-- 2017

|-- air.2017.nc

|-- hgt.2017.nc

|-- omega.2017.nc

|-- shum.2017.nc

|-- uwnd.2017.nc

‘-- vwnd.2017.nc

Similarly, for the NOAA-CIRES 20th Century Reanalysis product:

iwfiles = 1

MR_windfiles(1) = ‘/data/WindFiles/NOAA’

where the ﬁles are stored as follows:

/data/WindFiles/NOAA

|-- 2008

| |-- GRIB

| | |-- pgrbanl_mean_2008_HGT_pres.grib

| | |-- pgrbanl_mean_2008_RH_pres.grib

| | |-- pgrbanl_mean_2008_TMP_pres.grib

| | |-- pgrbanl_mean_2008_UGRD_pres.grib

| | |-- pgrbanl_mean_2008_VGRD_pres.grib

| | ‘-- pgrbanl_mean_2008_VVEL_pres.grib

| |-- pgrbanl_mean_2008_HGT_pres.nc

| |-- pgrbanl_mean_2008_RH_pres.nc

| |-- pgrbanl_mean_2008_TMP_pres.nc

| |-- pgrbanl_mean_2008_UGRD_pres.nc

| |-- pgrbanl_mean_2008_VGRD_pres.nc

| ‘-- pgrbanl_mean_2008_VVEL_pres.nc

|-- 2009

| -- ...

Note that the GRIB ﬁles are in version 1 format and cannot yet be directly read by MetReader.

They must ﬁrst be converted to NetCDF and placed as described above.

Step 3: Once the names of the NWP ﬁles are speciﬁed, the ﬁles must be queried to deter-

mine the scope of the available data.

call MR_Read_Met_DimVars([iyear])

The iyear argument is optional, but is expected for iwf=25 or 27 since MetReader needs to

know whether to allocate space for 365 or 366 days. Once the subroutine is called, each of

the NWP ﬁles is checked for existence, then the following public variables are set:

•All the projection parameters for the NWP grid.

•Met dim names() :: The names of the dimensions in the ﬁle in the order of: time,

pressure1, y, x, pressure2 (for Vz), pressure3 (for RH)

•Met var names() :: The names of the variables in the ﬁle according to the Table 8.1 of

Appendix 8.1:

•Met var conversion factor() :: For each of the variables, if the units is not as listed

above, then the correpsonding factor is set that converts to the expected units. For

example, if precipitation rate is given in mm/hr, then the conversion factor to the

expected units (kg/m2s) is 1/3600 or 2.778 ×10−4.

•Met var IsAvailable() :: set to .true. if the NWP ﬁle provides this variable.

•nx fullmet,ny fullmet,np fullmet :: lengths of grid for x (lon), y (lat) and p

•x fullmet sp,y fullmet sp,p fullmet sp :: values of the grid in km (degrees) and

hPa

•IsLatLon MetGrid :: .true. if the grid is speciﬁed in longitude and latitude

•IsGlobal MetGrid :: .true. if the grid is periodic in longitude. (Note: mapping

across the poles is not yet implemented).

•IsRegular MetGrid :: .true. if dx,dy (dlon,dlat) is constant

Step 4: Next, the calling program needs to deﬁne the type of grid onto which MetReader

will interpolate values. Namely, whether or not the computational grid is projectected, and

if so, which projection and associated values. This grid used by the calling program can be

independent of the grid used by the NWP ﬁles. The parameters in the list for the subroutine

below are the values needed by the libprojection.a library. Below is an example call from

Ash3d.

call MR_Set_CompProjection(IsLatLon,A3d_iprojflag,A3d_lam0, &

A3d_phi0,A3d_phi1,A3d_phi2, &

A3d_k0_scale,A3d_radius_earth)

If IsLatLon=.true. then all other projection parameters are ignored. Similarly, some of

the parameters are required and others not, depending on the projection used. Currently,

libprojection.a has implemented Polar stereographic (iprojflag=1), Albers Equal Area

(iprojflag=2), UTM (iprojflag=3), Lambert conformal conic (iprojflag=4), and Merca-

tor (iprojflag=5).

Step 5: The ﬁnal prepatory step is to evaluate the windﬁles provided with the spatial and

temporal requirements of the calling program.

call MR_Initialize_Met_Grids(nxmax,nymax,nzmax, &

x(1:nxmax),y(1:nymax),z(1:nzmax), &

IsPeriodic)

nxmax,nymax,nzmax are the sizes of the computational grid. x,y,z are the single-precision

grid values in km (or degrees). IsPeriodic indicates whether or not the computational grid

is periodic in x. This subroutine also determines the size of the sub-grid of the full NWP

data that is needed by the calling program.

call MR_Set_Met_Times(SimStartHour, SimDuration)

Here SimStartHour and SimDuration give the initial time (in hours since 1900 (or other base

year)) and the length of time needed in hours. This subroutine opens all the ﬁles listed in

MR windfiles() and veriﬁes that the ﬁles provided cover the requested time span. Then a

list is prepared of all the time steps and ﬁles needed to fully cover the requested time with the

step index (istep=1) corresponding to the step at or just prior to SimStartHour. The hours

between time steps is saved in MR MetStep Interval() and does not need to be constant.

3.2 Reading meteorological data

When handling data from the NWP ﬁles, there are three grids that MetReader uses:

•metP :: the native grid of the NWP ﬁle clipped to span the computational needs (pos-

sible re-ordered)

•metH :: the horizontal grid of the NWP ﬁle, but with the vertical coordinate mapped

from the pressure grid of the NWP ﬁle to the altitude grid of the computational grid.

•compH :: the full x,y,z of the computational grid.

Once the computational grid is speciﬁed and the sub-grid of the NWP is determined in step

5 above, the following public work spaces are allocated.

MR_dum2d_met_int(nx_submet,ny_submet) :: integer

MR_dum2d_met(nx_submet,ny_submet) :: float

MR_dum3d_metP(nx_submet,ny_submet,np_fullmet) :: float

MR_dum3d2_metP(nx_submet,ny_submet,np_fullmet) :: float

MR_dum3d_metH(nx_submet,ny_submet,nz_comp) :: float

MR_dum2d_comp_int(nx_comp,ny_comp) :: integer

MR_dum2d_comp(nx_comp,ny_comp) :: float

MR_dum3d_compH(nx_comp,ny_comp,nz_comp) :: float

nx comp,ny comp,np comp are the number of nodes in the computational grid and nx submet,

ny submet,np submet are the number of nodes of the NWP grid that is needed to span the

required computational grid.

To read data from the meteorological ﬁles, the fundamental subroutine is

call MR_Read_3d_MetP_Variable(ivar,istep)

where ivar is the code for the variable of interests (see Table 8.1) and istep is the index

of the sequence of time steps set up based on SimStartHour and SimDuration in Step 5

above. This subroutine provides a common interface regardless of the data format (ASCII,

NetCDF, GRIB2, etc.), data structure (latitude might be top-to-bottom or bottom-to-top,

pressure might be surface-to-top or top-down, grid might be staggered, longitude might be

−180 →180 or 0 →360). In all cases for 3-D variables, what is returned is the public work

array MR dum3d metP. This array is consistantly ordered such that xand y(or lon and lat)

increase with index (North to South NWP grids are ﬂipped) and with pordered from the

surface to top (pressure is high to low).

If 3-D data is needed on the metH grid,

call MR_Read_3d_MetH_Variable(ivar,istep)

can be used which ﬁrst populates MR dum3d metP, then interpolates onto MR dum3d metH.

For simply reading meteorological data onto the computational grid, use

call MR_Read_3d_Met_Variable_to_CompGrid(ivar,istep,[IsNext])

This subroutine reads the variable ivar from the NWP ﬁle into MR dum3d metP, then in-

terpolates these values onto MR dum3d metH, ﬁnally interpolating onto MR dum3d compH. The

optional argument IsNext is used when velocities are used at diﬀerent points in the program

and need to be saved. IsNext indicates that the velocity values MR v[x,y] metP next should

be copied to MR v[x,y] metP last.

To interpolate 3-D data onto the altitude levels of the computational grid, ﬁrst the geopo-

tential height data must be read. This could be achieved by the subroutine MR Read 3d MetP Variable

described above, but as a simulation advances, we typically need to have the geopotential

height data for the previous and the next time steps so that values can be interpolated

between steps. The subroutine

call MR_Read_HGT_arrays(istep,[reset_first_time])

is a specialized reader for ivar=1. The ﬁrst time this is called, both istep and istep+1

are called, populating the two public variables MR geoH metP last and MR geoH metP next.

Subsequent calls copy MR geoH metP next to MR geoH metP last and reads the next values

from istep+1. If the optional argument reset first time is given, both istep and istep+1

are directly read.

Similar read subroutines are available for 2-D variables.

call MR_Read_2d_Met_Variable(ivar,istep)

Given a 2-D variable identiﬁed with ivar, this populates the public work array MR dum2d met,

where again, 1:nx submet,1:ny submet corresponds to the subset of nodes of the NWP ﬁle

that is needed to span the computational grid.

call MR_Read_2d_Met_Variable_to_CompGrid(ivar,istep)

can be called similar to MR Read 2d Met Variable which directly reads the variable needed

and returns the values interpolated onto the public work space MR dum2d comp.

3.2.1 Regridding meteorological data

Internal to MetReader are a variety of regridding subroutines to interpolate from the metP

grid onto metH or compH. In some circumstances, data is initially needed just on the native

NWP grid, but then derived values might be required on the full computational grid. For

example, if air viscosity is needed for a particle fall model, temperature and pressure values on

the NWP grid can be read. Then viscosities can be calculated for each of the corresponding

nodes of the NWP grid. To interpolate these values from the metP grid to the compH grid,

the subroutine

call MR_Regrid_MetP_to_CompGrid(istep)

can be used. This takes the variable MR dum3d metP and interpolates it onto MR dum3d compH.

Similarly,

call MR_Regrid_MetP_to_MetH(istep)

interpolates MR dum3d metP to MR dum3d metH and

call MR_Regrid_Met2d_to_Comp2d

interpolates MR dum2d met to MR dum2d comp.

3.2.2 Wind velocity vectors

In some cases, the wind velocity vectors need to be mapped from the coordinate system of

the NWP ﬁles to the computational grid. Velocity components on the computational grid are

always provided as grid-relative. For some NWP ﬁles, such as the North American Regional

Reanalysis (NARR), the NWP grid is projected, yet the wind components are provided as

Earth-relative. In other cases, if the NWP data are provided on a projected grid, but the

computational grid is either lon/lat or on a diﬀerent projection, the grid-relative, projected

velocity components must be converted to that needed for the computational grid.

If the wind data are provided as grid-relative on a projected grid and something else is

needed, the subroutine

call MR_Rotate_UV_GR2ER_Met(MR_iMetStep_Now)

will read both U and V components and decompose the vector into earth-relative Easterly and

Northerly wind components with values at the metP grid nodes. These components are put in

the variables MR u ER metP and MR v ER metP. Once we have Earth-relative velocity compo-

nents (either from direct read of lon/lat data, from the subrouting MR Rotate UV GR2ER Met

or fron direct read of NARR data), if the computational grid is not Earth-relative, then these

Earth-relative components can be subsequently decomposed into grid-relative components on

the computational grid with

call MR_Rotate_UV_ER2GR_Comp(MR_iMetStep_Now)

This subroutine returns the U and V components on the compH grid through the two dummy

work space variables MR dum3d compH and MR dum3d compH 2

3.3 Additional Functions

Horizontal derivatives MetReader has subroutines for calculating horizontal derivatives

of variables on the metP grid. This is used for calculating velocity gradients for diﬀusivity

calculations, but could be applied to any variable. The two subroutines are MR DelMetP Dx

and MR DelMetP Dy. Both read the values from MR dum3d metP and return derivative values

on MR dum3d2 metP.

U.S. Standard Atmosphere MetReader also has several functions for calculating values

from the U.S. Standard Atmosphere.

•MR Temp US StdAtm(zin) :: Returns a temperature in K given a height in km.

•MR Z US StdAtm(pin) :: Returns a height in km given a pressure in hPa.

•MR Pres US StdAtm(zin) :: Returns a pressure in hPa given a height in km.

4 Supported types of meteorological data

MetReader can read meteorological data in a variety of diﬀerent formats.

4.1 1-D ASCII data

The simplest format for meteorological data is just a 1-D wind proﬁle in ASCII format.

To read this type, set iw = 1. The particular format of the 1-D data can be speciﬁed by

the iwf, where 1 indicates a user-speciﬁed column of values and 2 indicates that the ﬁles

are from the global radiosonde data available from https://ruc.noaa.gov/raobs/ or from

http://weather.uwyo.edu. In both these cases, there is no NCEP grid ID associated with

the sonde points so MR iGridCode is interpreted as the number of proﬁle points. Each point

at each time must have its own ﬁle containing the proﬁle data. MR idataFormat is not needed

(ASCII is assumed from iw = 1). Proﬁles at multiple times can be included by repeating the

sequence of proﬁle locations at the later times. All points must have proﬁles for all times and

ﬁles for subsequent time steps must be given in the same order. Also, all proﬁle ﬁles must be

in the same format (projection, columns of data). For example:

iw = 1

iwf = 2

igrid = 3

MR_iwindfiles = 6 # This must be an even multiple of MR_iGrid

PADQ_2018060100.dat # 00Z radio sonde at Kodiak, AK

PAKN_2018060100.dat # 00Z radio sonde at King Salmon, AK

PANC_2018060100.dat # 00Z radio sonde at Anchorage, AK

PADQ_2018060112.dat # 12Z radio sonde at Kodiak, AK

PAKN_2018060112.dat # 12Z radio sonde at King Salmon, AK

PANC_2018060112.dat # 12Z radio sonde at Anchorage,

4.1.1 User-speciﬁed proﬁles

User-speciﬁed proﬁles describe minimally, the horizontal velocity as a function of height at

a point (or points) in the domain. Beyond this constraint, the format is fairly general. The

format is as follows.

L01 string header line

L02 time(hr) nlev [ncol] [ivar(ncol)]

L03 x/lon y/lat [LLflag] [projection parameters]

L04 data

Ln EOF

Line 1 is a header line that is ignored

Line 2 contains at least the time of the proﬁles and the number of lines of data to read.

Optionally, the number of columns of data can be speciﬁed followed by a sequence of integers

speciﬁying the variable ID’s (see Table 8.1) for the corresponding columns. If neither of these

optional arguments ncol ivar(ncol) are given, then MetReader tests for the number of

columns present. If there are 3, then the data are read in as altitude (in m), wind speed (in

m/s), and wind direction (in degrees E of N, with the convention of where the wind is coming

from). If 5 columns are present, the fourth and ﬁfth columns correspond to pressure (in hPa)

and temperature (in ◦C), respectively. If the optional parameters on line 2 are given with

the number of columns of data and corresponding variables, then the variables can be read

in any order, but must include some measure of height and some measure of the wind vector.

Height can include either altitude (in m), or pressure (in hPa), or both. If only one of these

two is given, the other is ﬁlled according the the U.S. Standard Atmosphere. The measure of

the wind vector can be given either in U and V, or speed and direction. If temperature is not

provided, it is calculated from the pressure or altitude using the U.S. Standard atmosphere.

Line 3 contains the coordinate of the 1-D proﬁle. If two values are given, the coordinate

system is assumed to be that of the computational grid (either in projected or lon/lat grids).

If more that two parameters are given, then the parameters beyond 2 are interpreted to be the

list of parameters required by libprojection.a. If the LLflag is given as a third parameter

with a value of 1, then the coordinate is interpreted to be in longitude and latitude. If the

value is 0, then the coordinate system is projected with speciﬁcation deﬁned by subsequent

values on line 3.

Line 4 contains the start of nlev rows of data

Here is an example of the 3-column format.

Hanford

2 5 #wind time, number of levels

-120.0 46.20 #Longitude, latitude

0 10.000 90.00

5000 10.000 90.00

10000 10.000 90.00

15000 10.000 90.00

20000 10.000 90.00

Here is an example of a user-speciﬁed number of columns with data on a projected grid.

Hanford

0 5 5 1 2 3 0 5 #wind time, number of levels, nvar ivars(1:nvar)

-2062.26 2606.69 0 4 265.0 25.0 25.0 25.0 6371.229 # (-120.0 46.20) in LCC grid 212 coords

0 -10.000 0.00 1000.0 10.0

5000 -10.000 0.00 560.0 -5.5

10000 -10.000 0.00 262.0 -47.3

15000 -10.000 0.00 126.0 -58.1

20000 -10.000 0.00 58.0 -54.9

4.1.2 1-D radiosonde proﬁles (single or multiple times)

Instead of user-speciﬁed proﬁles, MetReader can also read radiosonde data. Both the global

archive as well as the 00Z and 12Z radiosonde data are available from the NOAA Earth System

Research Laboratory Rapid Update Cycle Radiosonde Database (https://ruc.noaa.gov/raobs/).

These data are also archived at the University of Wyoming

(http://weather.uwyo.edu/upperair/sounding.html). To use data in this format, set iwf

= 2. From both these sites, radiosonde data are availalbe in a variety of formats. The default

format for the UW site is ”Text: List“

72694 SLE Salem Observations at 00Z 20 Jun 2018

-----------------------------------------------------------------------------

PRES HGHT TEMP DWPT RELH MIXR DRCT SKNT THTA THTE THTV

hPa m C C % g/kg deg knot K K K

-----------------------------------------------------------------------------

1007.0 61 30.6 8.6 25 7.01 345 7 303.1 324.5 304.4

1002.0 110 29.4 9.4 29 7.44 349 8 302.4 324.9 303.7

1000.0 129 29.2 9.2 29 7.35 350 8 302.4 324.6 303.7

980.2 305 27.5 8.5 30 7.17 355 9 302.4 324.1 303.7

946.7 610 24.6 7.4 33 6.85 0 7 302.4 323.2 303.7

925.0 814 22.6 6.6 36 6.65 350 6 302.4 322.6 303.6

914.4 914 21.7 5.7 35 6.33 345 7 302.5 321.8 303.7

908.0 975 21.2 5.2 35 6.14 352 7 302.6 321.3 303.7

13.3 29602 -39.7 -76.7 1 0.08 66 18 802.1 803.1 802.2

11.7 30480 -39.0 -76.4 1 0.10 90 30 834.6 835.8 834.6

10.2 31394 -38.2 -76.2 1 0.12 80 19 869.7 871.2 869.8

10.0 31557 -38.1 -76.1 1 0.12 876.2 877.8 876.2

Station information and sounding indices

Station identifier: SLE

Station number: 72694

Observation time: 180620/0000

Station latitude: 44.91

Station longitude: -123.00

Station elevation: 61.0

Showalter index: 6.44

This ﬁle contains many pressure levels, but the radiosonde standard include a limited set of

”required“ pressure levels (1000, 925, 850, 700, 500, 400, 300, 250, 200, 150, and 100 mbar; and

supplementally 70, 50, 30, 20, 10 if the probe reaches those heights.). When MetReader reads

a ﬁle of this format, only these mandatory pressure levels are read. Only the pressure, height,

temperature, wind direction and wind speed are read. After the columnar data are read,

the Station number is read. From this number (72694 in the above example), the station

longitude, latitude and elevation are automatically populated from internally stored station

metadata available from https://ruc.noaa.gov/raobs/General Information.html. The

station list is truncated to just what is currently operational and to just current coordinates

(some stations have been moved or deactivated). Next the Observation time is read.

An alternative format is the FAA604 WMO/GTS format from https://ruc.noaa.gov/raobs/

or the nearly identical ”Text:Raw“ format from the University of Wyoming.

TTAA 70001 72694 99007 30672 34507 00129 29270 35008 92814 22666 35006 85542

17466 03511 70163 04859 09008 50582 10178 20015 40750 22974 23023 30953 39945

24033 25075 49164 24541 20220 52974 25050 15405 55180 26035 10660 60376 23011

88188 54573 25052 77999 31313 58208 82346 51515 10164 00006 10194 00508 09506

TTBB 70008 72694 00007 30672 11002 29470 22908 21266 33890 20469 44814 15067

55762 10261 66693 04259 77655 00456 88615 02757 99592 05350 11580 05756 22573

05764 33566 06368 44551 07765 55547 07762 66536 08563 77526 08166 88518 08766

99509 09378 11494 10782 22468 14374 33440 16981 44381 25773 55346 31962 66330

34346 77323 35738 88302 39743 99278 44357 11261 47757 22245 49568 33240 49977

44231 49578 55220 51375 66194 53373 77188 54573 88175 54774 99172 53376 11170

52777 22160 54379 33153 54180 44143 56979 55134 56379 66129 57578 77120 57778

88110 60177 99106 59977 11104 60976 22102 59977 31313 58208 82346 41414 12761

PPBB 70008 72694 90012 34507 35509 36007 90346 34507 02009 03008 90789 07002

16003 12508 91246 12505 12011 20008 9179/ 19506 19015 92025 21516 23018 23523

93046 23537 24524 25049 940// 25053 950// 26022

TTCC 70002 72694 70883 60377 11004 50095 57778 11020 30421 52181 07020 20686

45783 08022 88999 77999 31313 58208 82346

This format contains nearly the same information as the previous example, but requires

a bit of translation. Appendix F of

https://www.ofcm.gov/publications/fmh/FMH3/00-entire-FMH3.pdf gives the full spec-

iﬁcation. If the string ”TTAA“ is found in the ASCII ﬁle, this format is attemped ﬁrst,

otherwise the ”Text:List” is assumed. This WMO/GTS format is intended for the Rapid

Update Cycle data and does not contain the year or month (only the day-of-month and

hour) of the data. If this format is detected, the year and month of the at execution time is

assumed unless otherwise speciﬁed by the calling program.

4.2 Network of 1-D radiosonde proﬁles

In most of the world, the radiosonde launch sites are too dispers to form a meaningful network

across which we can interpolate values. The radiosonde data is most useful for the regions

of interest proximal to launch sites. Currently, the use of multiple sonde locations is not

implemented, but simple interpolation using a small number of sonde points is planned for

future versions of this library.

4.3 3-D forecast or reanalysis data

MetReader’s preferred format for 3-D forecast and reanalysis ﬁles is NetCDF. Many prod-

ucts are available directly in NetCDF. format such as NCEP/NCAR Reanalysis 1 or NASA

GEOS-5. These products generally require NetCDF version 4. Most of the NCEP forecast

products are provided in GRIB2 format. To convert these forecast products to NetCDF for-

mat, MetReader relies on the NetCDF. java package

(https://www.unidata.ucar.edu/software/thredds/current/netcdf-java/). The con-

version script in the autorun scripts folder are linked to netcdfAll-4.5 however any recent

version should work. Older versions create NetCDF ﬁles with diﬀerent variable names.

Many of the forecast and reanalysis products are built in to MetReader where the grid

geometry, variable list, and pressure levels are preset. These include all the iwf numbers

listed in section 3.1. If the products change such that the pressure levels diﬀer or if variable

names change, then the source code will need to be modiﬁed to account for the changes.

Alternatively, a template ﬁle could be used as described in section 5 below.

MetReader can also read GRIB2 ﬁles directly for certain forecast products, including

the NAM 196 grid over HI (iwf=11), the NAM 91 grid over AK (iwf=13) and the GFS

0.25 ◦and 0.5◦products (iwf=22,20). To read these GRIB2 ﬁles, an index ﬁle containing

the locations of all the records must be created. This index ﬁle can be created by the

utility gen GRIB2 index, or if the ﬁle does not exist at run-time, can be generated through

the subroutine call MR Set Gen Index GRIB(filename). In practice, if windﬁles will be used

more than a few times, it is generally worthwhile to convert them to NetCDF prior to usage by

MetReader. The current implementation of the GRIB2 reader will read each of the required

GRIB2 records into memory, decompress the full gridded data, then extract the needed sub-

grid; whereas the NetCDF interface allows a more natural direct access to sub-grids. For

high resolution, global grids where only a small sub-grid is needed, the impact of reading and

uncompressing full grids will be noticable.

5 Custom meteorological ﬁle speciﬁcation

As an alternative to using a particular forecast or reanalysis product with hard-coded ﬁle

structure, a template ﬁle can be used the allows a custom speciﬁcation of a NetCDF ﬁle.

The custom template is indicated by iwf=0 and setting MR iwf template to the name of the

template ﬁle. The template ﬁle has the following format.

Line 1: The line of projection parameters as expected by libprojection.a. e.g.

Polar-stereographic Grid 91 0 1 -150.0 90.0 0.933 6371.229

Polar-stereographic Grid 216 0 1 -135.0 90.0 0.933 6371.229

Mercator Grid 196 0 5 198.475 20.0 0.933 6371.229

Lambert Conformal Grid 212 0 4 265.0 25.0 25.0 25.0 6371.229

Lambert Conformal Grid 221 0 4 -107.0 50.0 50.0 50.0 6371.229

Line 2: StepInterval [T/F] :: time interval in hours, and ﬂag indicating whether or

not to use leap years (Assumed Tif not provided)

Line 3: ndims nvars :: number of dimensions and variable that will be listed

Line 4-: list of dimensions where each row speciﬁes the information about the dimension.

For example

d 1 1.6667e-2 time hours since

d 2 100.0 lev Pa

In this example, the dsigniﬁes that the row describes a dimension, 1is the dimension number,

1.6667e-2 is a scaling factor, and time is the name of the dimension. The dimensions should

be listed in the following order: time, pressure used for primary state variables (velocity,

temperature), y (or longitude), x (or latitude), pressure used for vertical velocities, and

pressure used for moisture variables. Additional dimensions can be listed to support other

speciﬁc variables. The scaling factor is the factor needed to convert the dimension from the

units provided to the units required. In this example, the time values are supplied in minutes,

and must be multiplied by 1.6667e-2 to be in the expected units of hours. Similarly, pressure

is supplied in hPa but is expected in Pa.

Line 4+ndims- : list of variables where each row speciﬁes the information about the

variable.

v 4 2 1 1.0 HGT H gpm

v 4 2 2 1.0 UGRD U m/s

v 4 2 3 1.0 VGRD V m/s

v 4 5 4 1.0 VVEL OMEGA Pa/s

v 4 2 5 1.0 TMP T K

v 4 6 30 1.0 RH RH %

v 4 6 31 1.0 SPFH SH kg/kg

In this example, the ﬁrst character, v, signiﬁes that the row describes a variable. The next

integer is the dimensionality of the variable (3or 4). It is assumed that the variable is a

function of x, y, and t, but if also a function of pressure, the vertical dimension needs to be

speciﬁed. The next integer indicated which of the vertical dimensions listed earlier in the

ﬁle are used for this variable. The fourth item on the line (third integer) is the variable ID

according to Table 8.1. Next is the scaling factor to convert the provided values to the units

expected for the variable. The next two ﬁelds are the WMO variable name and the variable

name given in the NetCDF ﬁle.

There are several limitations of the template for the custom NWP reader. Firstly, only the

NetCDF reader is currently implemented. Secondly, currently all variables are assumed to be

transient; so land-use or topography cannot be read with this scheme. Variables that cannot

be simply scaled to the expected units cannot be described in this template. For example,

WRF ﬁles (iwf=50) uses a staggered grid with pressure and geopotential given both as a base

value plus a perturbation. Lastly, to determine the start time of the data, a reference time

must be read. First the time variable is checked for the GRIB orgReferenceTime attribute.

If this is not found, then the variable reftime is checked, if it exists.

Several examples of these template ﬁles used with NAM and GFS forecast products are

shown in Apendix 8.3.

6 Additional tools/Examples

In the tools folder, three programs are included the illustrate the use of the library.

6.1 MetCheck

This utility is used for checking the validity of the NWP ﬁles. In some cases, the downloading

of ﬁles might be interupted or the ﬁles on the NCEP server might be incomplete or corrupt.

This utility opens each of the ﬁles and reads the full grid for the variables: geopotential

height, Vx, Vy, Vz, and temperature. If any values are outside of expected ranges, then the

program stops returning a non-zero stop-code (stop 1). Usage:

MetCheck iwf idf filename [year]

6.2 MetSonde

This utility is used for probing the NWP ﬁles and returing the temperature as a function of

height. Usage:

MetSonde lon lat YYYY MM DD HH [WIND_ROOT]

The program assumes that the GFS and NCEP ﬁles are placed in the default directory, or

at least in default subdirectories oﬀ of WIND ROOT. Values are interpolated onto the requested

point and time and are writen to a ﬁle (GFS prof.dat) in the current working directory. This

3-column ﬁle contains the height (in km), pressure (in Pa) and temperature (in ◦C).

6.3 MetTraj

This utility takes a similar argument list as MetSonde, but instead of probing a single point

and time, this utility calculates trajectories within either a GFS forecast package or the NCEP

reanalysis ﬁles. This utility must be compiled with either a -DFORWARD or -DBACKWARD pre-

processor ﬂag to generate separate executables for forward or backward trajectories. The

location of the windﬁles is assumed to be the default for GFS and NCEP. For forward tra-

jectories, forecast package beginning most closely prior to the requested start time is used

unless the start time is greater than two weeks from present. If so, the NCEP ﬁles are used.

For the backward trajectories, the forecast package chosen is that which can accommodate

the default 24-hours of backward integration.

For each of the trajectory calculations, ﬁles are writen to the current working directory

with the longitude and latitude of the trajectory in 1-hour increments at various elevations.

The default elevations are 5000, 10000, 20000, 30000, 40000, and 50000 ft. Files for forward

trajectories are named ftraj[1-6].dat while the backward trajectories are btraj[1-6].dat.

Optionally, the length of time to integrate and a user-speciﬁed list of output elevations

can be given. Elevations are given on the command line must be in km. Usage:

MetTraj_F lon lat YYYY MM DD HH [FC_hours nlev lev1 lev2 ...]

7 Windﬁle managment scripts

Scripts used to manage GFS and NCEP Reanalysis ﬁles are provided in the folder autorun scripts.

The script autorun gfs0.5deg 00 (and the dependent scripts get gfs0.5deg.sh and

convert gfs0.5deg.sh) is used for downloading and converting the 0.5◦GFS ﬁles from

NCEP. This script is intended to be run from a cron job and take as a parameter, the hour of

the forecast package. For example autorun gfs0.5deg.sh 0 will download for 00Z for the

current date. These scripts use a default root download directory of /data/WindFiles, but

this can be modiﬁed within the scripts. The GFS ﬁles will be downloaded to

/data/WindFiles/gfs/gfs.YYYYMMDDHH where HH is the forecast hour (00, 06, 12, or 18).

The forecast ﬁles from hours 0-99 are downloaded then converted using netcdf-java 4.5. The

path this package is set to /ncj/netcdfAll-4.5.jar but can be modiﬁed in convert gfs0.5deg.sh.

Similarly, the script get NCEP 50YearReanalysis.sh manages the downloading of the

NCEP reanalysis ﬁles. These are placed in /data/WindFiles/NCEP/YYYY/

These scripts are intended to be run as cron jobs. The following line can be added to the

crontab to download the ﬁles once they are available.

01 22 * * * /opt/USGS/Ash3d/bin/autorun_scripts/autorun_gfs0.5deg.sh 0 > gfs00_log 2>&1

01 11 * * * /opt/USGS/Ash3d/bin/autorun_scripts/autorun_gfs0.5deg.sh 12 > gfs12_log 2>&1

01 01 * * Sun /opt/USGS/Ash3d/bin/autorun_scripts/autorun_NCEP_50YearReanalysis.sh > NCEP_50yr_log 2>&1

Also included in autorun scripts is a simple stand-alone script (grib2nc.sh) for con-

verting GRIB2 ﬁles to NetCDF using netcdf-java.

8 Appendix

8.1 Variable codes

Table 1: Variable codes

Variable type ID Name dimensions

3d Mechanical

1 Geopotential Height gmp or m2/s2

2 Vx m/s

3 Vy m/s

4 Vz Pa/s

5 Temperature K

6 Wind speed m/s

7 Wind direction deg East of North

Surface

10 Planetary Boundary Layer Height m

11 U @ 10m m/s

12 V @ 10m m/s

13 Friction velocity m/s

14 Displacement Height m

15 Snow cover %

16 Soil moisture kg/m2

17 Surface Roughness m

18 Wind gust speed m/s

19 surface temperature K

Atmospheric Structure

20 pressure at lower cloud base Pa

21 pressure at lower cloud top Pa

22 temperature at lower cloud top K

23 Total Cloud cover %

24 Cloud cover (low) %

25 Cloud cover (convective) %

Moisture

30 Rel. Hum %

31 QV (speciﬁc humidity) kg/kg

32 QL (liquid) kg/kg

33 QI (ice) kg/kg

Precipitation

40 Categorical rain 0 or 1

41 Categorical snow 0 or 1

42 Categorical frozen rain 0 or 1

43 Categorical ice 0 or 1

44 Precipitation rate large-scale (liquid) kg/m2s

45 Precipitation rate convective (liquid) kg/m2s

46 Precipitation rate large-scale (ice) kg/m2s

47 Precipitation rate convective (ice) kg/m2s

8.2 NWP product ID (iwf)

Several NWP product (both reanalysis and forecast) are recognized and do not need template

ﬁles. These are listed in the table below by the format code. iwf=1,2 are ASCII ﬁles.

iwf=3-19 are reserved for products with projected grids. iwf=20-49 are reserved for global

(lon/lat) grids. iwf=50 is for NetCDF output from Weather Research and Forecasting (WRF)

simulations.

Table 2: NWP product ID

iwf Product NCEP Grid resolution

0 Custom format based on template

1 ASCII proﬁle

2 Radiosonde data

3 North American Regional Reanalysis NARR-A 221 32 km

4 North American Regional Reanalysis NARR-A+B 221 32 km

5 NAM Regional Alaska 216 45 km

6 NAM N. Hemisphere 104 90 km

7 NAM Regional CONUS 212 40 km

8 NAM Regional CONUS 218 12 km

10 NAM Regional Alaska 242 11.25 km

11 NAM Regional Hawaii 196 2.5 km

12 NAM Regional Alaska 198 5.953 km

13 NAM Regional Alaska 91 2.976 km

20 GFS 4 0.5◦

21 GFS 3 1.0◦

22 GFS 193 0.25 ◦

23 NCEP-DOE Reanalysis 2 2 2.5◦

24 NASA-MERRA-2 Reanalysis None 0.625 ×0.5◦

25 NCEP/NCAR Reanalysis 1 2 2.5◦

27 NOAA-CIRES 20th Century Reanalysis 2 2.5◦

28 ECMWF ERA-Interim Reanalysis 170 ∼0.7◦-Gaussian

32 Air Force Weather Agency subcenter = 0 None 0.25◦

33 CCSM3.0 Community Atmosphere Model None 3.75 ×3.7◦

40 NASA GEOS-5 Cp None 0.625 ×0.5◦

41 NASA GEOS-5 Np None 0.3125 ×0.25◦

50 WRF - output None

8.3 Example Template ﬁles

NCEP−Grids

Figure 1: Outlines of North America Mesoscale (NAM) and Global Forecast System (GFS)

models from NCEP that are compatible with MetReader template ﬁles.

8.4 NAM 221 Regional N.America (32.5 km)

nam.t00z.awip3200.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 2: NAM 221, Regional N. America 32.5 km Lambert Conformal Conical

n221_template.txt

0 4 -107.0 50.0 50.0 50.0 6371.229 Projection params line

3.0 Time interval

9 29 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric1 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric1 Pa

d 6 1.0 isobaric1 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 CPRAT Convective_Precipitation_Rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.5 NAM 216 AK (45.0 km); NAM 242 AK (11.25 km)

nam.t00z.awipak00.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

http://motherlode.ucar.edu/native/conduit/data/nccf/com/nam/prod/nam.YYYYMMDD/

Figure 3: NAM 216, AK 45.0 km Polar Stereographic

n216_template.txt

0 1 -135.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

9 27 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric1 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric1 Pa

d 6 1.0 isobaric1 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 CPRAT Convective_Precipitation_Rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

Grid 242 uses the same projection and domain as Grid 216, but with 11.25 km grid

spacing.

nam.t00z.awak3d00.grb2.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

n242_template.txt

0 1 -135.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

9 27 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric2 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric Pa

d 6 1.0 isobaric2 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric6 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 CPRAT Convective_Precipitation_Rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.6 NAM 91 AK (2.95 km); NAM 198 AK (5.9 km)

nam.t00z.alaskanest.hiresf00.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 4: NAM 91, AK 2.95 km Polar Stereographic (previously NAM 198, AK 5.9 km)

n091_template.txt

0 1 -150.0 90.0 0.933 6371.229 Projection params line

1.0 Time interval

9 29 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric2 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric2 Pa

d 6 1.0 isobaric2 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric3 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 CPRAT Convective_Precipitation_Rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.7 NAM 243 Eastern N. Pac./HI (0.40 ◦)

nam.t00z.awiphi00.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 5: NAM 243, Eastern N. Pac./HI 0.4◦

n243_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

9 24 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric2 Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 1.0 isobaric1 Pa

d 6 1.0 isobaric2 Pa

d 7 1.0 height_above_ground m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.8 NAM 182 HI (0.108 ◦)

nam.t00z.afwahi00.grb2.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 6: NAM 182, HI 0.108 ◦

n182_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

8 22 ndims, nvars

d 1 1.0 time1 hours since

d 2 1.0 isobaric Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 1.0 isobaric Pa

d 6 1.0 isobaric Pa

d 7 1.0 height_above_ground2 m

d 8 1.0 depth_below_surface_layer m

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

8.9 NAM 196 HI (2.5 km)

nam.t00z.hawaiinest.hiresf00.tm0

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 7: NAM 196, AK 2.5 km Mercator

n196_template.txt

0 5 198.475 20.0 6371.229 Projection params line

1.0 Time interval

9 27 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric2 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric2 Pa

d 6 1.0 isobaric2 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.10 NAM 211/212/218/227 CONUS

Figure 8: NAM 211/212/218/227 CONUS Lambert Conformal Conical (dots correspond

to the 81.3 km 211 grid)

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

NAM 211 CONUS (81.3 km) :: nam.t00z.awp21100.tm00

n211_template.txt

0 4 265.0 25.0 25.0 25.0 6371.229 Projection params line

6.0 Time interval

9 18 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric Pa

d 6 1.0 isobaric Pa

d 7 1.0 height_above_ground1 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

NAM 212 CONUS (40.6 km) :: nam.t00z.awip3d00.tm00

n212_template.txt

0 4 265.0 25.0 25.0 25.0 6371.229 Projection params line

3.0 Time interval

9 29 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric1 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric1 Pa

d 6 1.0 isobaric1 Pa

d 7 1.0 height_above_ground2 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric1 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 CPRAT Convective_Precipitation_Rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

NAM 218 CONUS (12.2 km) :: nam.t00z.awphys00.grb2.tm00

n218_template.txt

0 4 265.0 25.0 25.0 25.0 6371.229 Projection params line

1.0 Time interval

9 21 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric1 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric1 Pa

d 6 1.0 isobaric Pa

d 7 1.0 height_above_ground4 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

NAM 227 CONUS (5.1 km) :: nam.t00z.conusnest.hiresf00.tm00

n227_template.txt

0 4 265.0 25.0 25.0 25.0 6371.229 Projection params line

1.0 Time interval

9 27 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric2 Pa

d 3 1.0 y km or deg

d 4 1.0 x km or deg

d 5 1.0 isobaric2 Pa

d 6 1.0 isobaric2 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 17 1.0 SFCR Surface_roughness_surface m

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 3 0 20 1.0 PRES Pressure_cloud_base Pa

v 3 0 21 1.0 PRES Pressure_cloud_tops Pa

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 44 1.0 PRATE Precipitation_rate_surface kg.m-2.s-1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 47 1.0 NCPCP Large-scale_precipitation_non-convective_surface_0_Hour_Accumulation kg.m-2

8.11 NAM 181 Caribbean (0.108 ◦)

nam.t00z.afwaca00.grb2.tm00

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/nam.YYYYMDD/

Figure 9: NAM 181, Caribbean 0.108 ◦

n181_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

8 22 ndims, nvars

d 1 1.0 time1 hours since

d 2 1.0 isobaric Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 1.0 isobaric Pa

d 6 1.0 isobaric Pa

d 7 1.0 height_above_ground2 m

d 8 1.0 depth_below_surface_layer m

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 13 1.0 FRICV Frictional_Velocity_surface m.s-1

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 23 1.0 TCDC Total_cloud_cover_entire_atmosphere %

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 6 31 1.0 SPFH Specific_humidity_isobaric kg/kg

v 4 9 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

v 4 9 33 1.0 SNMR Snow_mixing_ratio_isobaric kg/kg

v 3 0 40 1.0 CRAIN Categorical_Rain_surface 0 or 1

v 3 0 41 1.0 CSNOW Categorical_Snow_surface 0 or 1

v 3 0 42 1.0 CFRZR Categorical_Freezing_Rain_surface 0 or 1

v 3 0 43 1.0 CICEP Categorical_Ice_Pellets_surface 0 or 1

v 3 0 45 1.0 APCP Total_precipitation_surface_0_Hour_Accumulation kg.m-2

v 3 0 46 1.0 ACPCP Convective_precipitation_surface_0_Hour_Accumulation kg.m-2

8.12 GFS 3/4/193

Figure 10: GFS 3,4,193, (dots correspond to the 1.0◦NAM 3 grid)

Available from:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.YYYYMDD/

GFS NCEP Grid 3 (1.0◦) :: gfs.t00z.pgrb2.1p00.f000.nc

n003_template.txt

GFS NCEP grid 4 (0.5◦) :: n004_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

9 13 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric3 Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 1.0 isobaric2 Pa

d 6 1.0 isobaric3 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 5 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

GFS NCEP grid 193 (0.25 ◦) :: n193_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

9 13 ndims, nvars

d 1 1.0 time hours since

d 2 1.0 isobaric3 Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 1.0 isobaric2 Pa

d 6 1.0 isobaric3 Pa

d 7 1.0 height_above_ground3 m

d 8 1.0 depth_below_surface_layer m

d 9 1.0 isobaric4 Pa

v 4 2 1 1.0 HGT Geopotential_height_isobaric gpm

v 4 2 2 1.0 UGRD u-component_of_wind_isobaric m/s

v 4 2 3 1.0 VGRD v-component_of_wind_isobaric m/s

v 4 5 4 1.0 VVEL Vertical_velocity_pressure_isobaric Pa/s

v 4 2 5 1.0 TMP Temperature_isobaric K

v 3 0 10 1.0 HPBL Planetary_Boundary_Layer_Height_surface m

v 4 7 11 1.0 UGRD u-component_of_wind_height_above_ground m/s

v 4 7 12 1.0 VGRD v-component_of_wind_height_above_ground m/s

v 3 0 15 1.0 SNOD Snow_depth_surface m

v 4 2 16 1.0 SOILW Volumetric_Soil_Moisture_Content_depth_below_surface_layer Fraction

v 3 0 18 1.0 GUST Wind_speed_gust_surface m/s

v 4 6 30 1.0 RH Relative_humidity_isobaric %

v 4 5 32 1.0 CLWMR Cloud_mixing_ratio_isobaric kg/kg

8.13 NASA GEOS-5

Figure 11: NASA GEOS-5, 0.625/0.5◦

Available from:

ftp://gmao_ops@ftp.nccs.nasa.gov/fp/forecast//

NASA GEOS-5 Cp (0.625/0.5◦) ::

GEOS.fp.fcst.inst3_3d_asm_Cp.YYYYMMDD_00+YYYYMMDD_mmmm.V01.nc4

nGCp_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

6 7 ndims, nvars

d 1 1.6667e-2 time hours since

d 2 100.0 lev Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 100.0 lev Pa

d 6 100.0 lev Pa

v 4 2 1 1.0 HGT H gpm

v 4 2 2 1.0 UGRD U m/s

v 4 2 3 1.0 VGRD V m/s

v 4 5 4 1.0 VVEL OMEGA Pa/s

v 4 2 5 1.0 TMP T K

v 4 6 30 1.0 RH RH %

v 4 6 31 1.0 SPFH SH kg/kg

NASA GEOS-5 Np (0.25/0.3125 ◦) ::

GEOS.fp.fcst.inst3_3d_asm_Np.YYYYMMDD_00+YYYYMMDD_mmmm.V01.nc4

nGNp_template.txt

1 1 -150.0 90.0 0.933 6371.229 Projection params line

3.0 Time interval

6 7 ndims, nvars

d 1 1.6667e-2 time hours since

d 2 100.0 lev Pa

d 3 1.0 lat km or deg

d 4 1.0 lon km or deg

d 5 100.0 lev Pa

d 6 100.0 lev Pa

v 4 2 1 1.0 HGT H gpm

v 4 2 2 1.0 UGRD U m/s

v 4 2 3 1.0 VGRD V m/s

v 4 5 4 1.0 VVEL OMEGA Pa/s

v 4 2 5 1.0 TMP T K

v 4 6 30 1.0 RH RH %

v 4 6 31 1.0 SPFH SH kg/kg

Met Reader Manual

Navigation menu

Versions of this User Manual:

Views

Navigation