EMC's Model Evaluation Group

 The Model Evaluation Group (MEG) community is established to interact with the user community on issues related to the forecast systems of NCEP's Environmental Modeling Center (EMC).    It is used to discuss overall model performance and provide feedback on operational and parallel versions of the models which comprise the production suite.

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RE: 00Z 2-m Temps consistently colder in FV3 over higher terrain

RE: 00Z 2-m Temps consistently colder in FV3 over higher terrain
10/25/17 2:52 PM as a reply to Timothy Barker.

A little bit of follow-up: there were some changes to EMC's FV3 runs on 7 September, but they affected primarily cloud water and stratospheric temperature and winds. I think this 00Z behavior may have been happening near sundown this entire time, but sundown is now closer to 00Z so we're noticing it more. I've attached an image from the FV3/GFS plume comparison for Boise 2-m temperature in the first 72-h of the 12Z 23 October cycle with some obs overlaid. Between 21Z and 00Z the temperature in the GFS (blue line) decreases but the temperature in the FV3 (orange line) either decreases less or even increases. The result is an approximately 3-degree difference each evening at 00Z. The two catch up again by 03Z. Historically, the GFS has decreased temperatures too quickly around 00Z; this appears to be better performance in the FV3. It's something to keep in mind as our evaluation continues.

As for the terrain, it's different because a different filter is applied.