00 UTC
There is confirmation of the GOES sounder moisture data getting into the Eta model system by seeing the very small differences at the intial times. For today:
00 UTC
12 UTC
GOES-ETA Comparisons from 00UTC, 30OCT97
As of 12UTC, 24Sep97 most of the GOES-9 Sounder moisture began going into the Eta system. Note the smaller differences in the Eastern Pacific between 00UTC on September 24 and 12UTC on September 24. Some of the GOES-8 data was getting into the system.
GOES-ETA Comparisons from 00UTC, 24Sep97 and 12UTC, 24Sep97
The Eta model ingested all the available GOES-8/9 sounder 3-hourly moisture data for the first time at 12UTC on 22 October, 1997. Note the smaller differences over the Gulf of Mexico compared to the early time (top panel), when basically GOES-9 sounder data was getting into the Eta system. The white dots denote the locations of the operational retrievals.
GOES-ETA Comparisons from 00UTC, 22Oct97 and 12UTC, 22Oct97
Only sounder data 30 minutes before the top of the hour (00, 03, 06 UTC, etc.) was getting into the Eta model system prior to October 22, 1997. The beige dots (before the top of the hour) denote the area of possible retrievals which could have gotten into the Eta model prior to 12UTC on 22Oct97. The blue dots (after the top of the hour) denote the area of possible retrievals which were not getting into the Eta model prior to 12UTC on 22Oct97.
GOES Sounder Scan time plot
Total precipitable water (vertically integrated water vapor) derived from the GOES-8/10 sounders is currently being processed in realtime at CIMSS. The initial total precipitable water (mm) from the operational forecast model (Eta) at the National Centers for Environmental Prediction (NCEP) in Washington D. C. is routinely compared to precipitable water observed by the GOES-8/10 sounders. A plot of differences show where the Eta analysis and the GOES observations disagree. Postive values indicate the GOES sounders are 'seeing' an atmosphere that contains more moisture than the Eta analysis. These differences can lead to errors in the computer forecast. A plot of the locations of the GOES observations is also given.
Initial Eta PW (mm)
Initial Eta PW with GOES-8/10 PW (mm)
GOES-8/10 PW minus Initial Eta PW (mm)
Here is the initial total precipitable water (mm) from the NCEP Eta model operational forecast on 20May97 at 12UTC as compared to observations from the GOES-8/9 sounders. Sounding locations are shown in the upper right. +/- 11 mm differences are present in the Gulf of Mexico. The drying southeast of Cuba is supported by a minimum (blue) area in SSM/I total precipitable water field as viewed by the DMSP satellite.
GOES-ETA Comparison from 12UTC, 20May97
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