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: FV3 "snowy" forecast for Mid-Atlantic Dec 8-9, 2017

RE: FV3 "snowy" forecast for Mid-Atlantic Dec 8-9, 2017
Answer
12/8/17 4:16 AM as a reply to Steven Zubrick.
This is a good case. The latest model runs (00Z 8 December GFS, NAM, and NAM nest) have a snowier solution than we were seeing just this morning, and especially compared to the 00Z 7 December initializations. I've noticed the FV3 will occasionally amplify the pattern more than the GFS. I just caught onto this behavior recently, so I don't know how common it has been or will be. Attached is a 66-h 250-hPa wind speed forecast from the 12Z 7 December initialization. In the difference plot (FV3 minus GFS) warm colors are present along the poleward side of the jets, which indicates more poleward amplification (ridge building) north of extratropical cyclones in the FV3. Greater ridge building often (always?) coincides with more westward storm tracks, which is consistent with what Steve noted in his original post. This post is very speculative, but it will be something to watch this winter.