2.14. GDAS: Ice

Description

“The Global Data Assimilation System (GDAS) is the system used by the National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) model to place observations into a gridded model space for the purpose of starting, or initializing, weather forecasts with observed data.” from NOAA NCEI

Sample image

Categorical freezing rain.

../../_images/gdas_frzr.png
Recommended use

“Place observations into a gridded model space for the purpose of starting, or initializing, weather forecasts with observed data” from NOAA NCEI

File format

  • Grib2

Location of data

NCDC/NCEI: https://www.ncdc.noaa.gov/data-access/model-data/model-datasets/global-data-assimilation-system-gdas

Ice data is in the first two rows in the “Product Types” table.

Access restrictions

None

Spatial resolution, grid, or coverage

The spatial coverage is as follows. Latitude: 90.000000 to -90.000000 Longitude: 0.000000 to 359.750000

There are three spatial resolution options: 1° by 1°, 0.5° by 0.5°, and 0.25° by 0.25°

Temporal resolution

  • Model cycle: 4/day: 00, 06, 12, 18UTC

  • Output Timestep: Anl, +00, +03, +06, +09 hours

Starting and/or ending dates

  • Historical Dataset: 21Apr2019 – 11May2020

  • Present Dataset: 05Jun2020 – Present

Data latency

Present data set appears to be a 6-7 day latency (no documented latency)

Variables available

Here is a list of relevant variables. There are more in the grib2 files.

  • Cloud mixing ratio, CMWR

  • Ice water mixing ratio, IWMR

  • Rain water mixing ratio, RWMR

  • Snow Mixing Ratio, SNMR

  • Graupel, GRLE

  • Ice concentration [ice=1, no ice=0], CI

  • Ice Growth Rate, ICEG

  • Percent frozen precipitation, CPOFP

  • Precipitation Rate, PRATE

  • Categorical Snow, CSNOW

  • Categorical Ice Pellets, CICEP

  • Categorical Freezing Rain, CFRZR

  • Categorical Rain, CRAIN

  • Snow depth, SNOD

  • Water equiv. of accum. snow depth, SDWE

METplus Use Cases

Link to METplus Use Cases for this dataset.

Keywords

Note

Current Dataset: VxDataGDAS

Note

Data Labels: DataTypeGridded, DataLevelSurface, DataProviderNOAA, DataApplicationPrecipitation, DataApplicationMarineAndCryo