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Eta Model Runs (ETA)

Information updated on August 10, 2006, 2:07 pm GMT


General Data Description

Eta is one of NCEP's mesoscale numerical weather prediction models. The name "Eta" derives from the model's vertical coordinate known as the "eta" or "step-mountain" coordinate. The data archived by ARM come from the 00Z and 12Z model runs and include the 0h-analysis and 6h-forecast data resulting in 4 files per day (see input file table below).

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Data Stream Names

Measurement Description

Note: All the data files are in the GRIB format

Description of sgpalleta12X1.00
Description of earlier versions of eta model

Temporal Coverage

Data Availability and Retrieval:
The following data are available at the ARM Archive ( www.archive.arm.gov ).
To retrieve files, send e-mail to armarchive@ornl.gov. Include the datastream names and time period that you require.

Data Stream NameStart Date End Date
sgpalleta90X1.00 06/16/1993 02/25/1997
sgpalleta48X1.00 03/14/1997 02/08/1998
sgpalleta32X1.00 02/09/1998 09/26/2000
sgpalleta32X1.00 (actually 22 km resolution) ** 09/27/2000 11/27/2001
sgpalleta12X1.00 *** 11/28/2001

Notes:
* Current Eta data are available at the ARM Archive approximately 4 days after they are generated.
** Note some of the files named sgpalleta32X1.00 are actually files with 22 km rather than 32 km resolution.

See Data Quality Report (DQR) D011228.2 at http://www.db.arm.gov/PIFCARDQR/.
*** On 2005-01-25 NCEP changed the name of the "eta" product to NAM (North American Mesoscale), ARM continues to maintain the data in the same datastream name sgpalleta12X1.00.

The data are available 6 hours after the model is run. e.g. t00z is available at 6 GMT and t12z is available at 18 GMT.

Area Covered

NAM (ETA-12) grid 96 coverage map

Data Stream Inputs

Prior to 2005-01-25, the original data file names were as follows

NCEP filenameARM filenameType
eta.T00Z.EGRD3D00.tm00sgpalleta12X1.00.yyyymmdd.000000.rawAnalysis
eta.T00Z.EGRD3D06.tm00sgpalleta12X1.00.yyyymmdd.060000.raw6h-forecast
eta.T12Z.EGRD3D00.tm00sgpalleta12X1.00.yyyymmdd.120000.rawAnalysis
eta.T12Z.EGRD3D06.tm00sgpalleta12X1.00.yyyymmdd.180000.raw6h-forecast

On 2005-01-26, NCEP changed model name from eta to nam but ARM maintains the eta file names:

NCEP filenameARM filenameType
nam.t00z.egrd3d00.tm00sgpalleta12X1.00.yyyymmdd.000000.rawAnalysis
nam.t00z.egrd3d06.tm00sgpalleta12X1.00.yyyymmdd.060000.raw6h-forecast
nam.t12z.egrd3d00.tm00sgpalleta12X1.00.yyyymmdd.120000.rawAnalysis
nam.t12z.egrd3d06.tm00sgpalleta12X1.00.yyyymmdd.180000.raw6h-forecast

Notification Form Link

Notification form for sgpalleta32X1.00
Notification form for sgpalleta48X1.00

Related Links

Lesson Materials for Eta Characteristics, Biases, and Usage NCEP Eta/EDAS and the GCIP Project
Model Output Location Time Series (MOLTS) Documentation
Model Name Changes 2005-01-25

Contacts

Data Source

Data User Notes

Users should check Data Quality Reports (DQRs) concerning these files. The DQRs can be found at the PIFCARDQR Web site.

Acronyms

GRIB	GRIdded Binary
MOLTS	Model Output Location Time Series
NCEP	National Centers for Environmental Prediction
NWP	Numerical Weather Prediction
SGP	Southern Great Plains