Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 304 AM EDT Wed May 13 2020 Valid May 13/0000 UTC thru May 16/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Model Evaluation Including Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Closed low over Alberta tracking to the Upper Great Lakes Thu...then across Northern New England Fri... ...Surface low moving from the north central US Wed night into Northern New England Fri... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: ECMWF/UKMET/GFS/GEFS Mean Confidence: Average Similar to the GFS, the 00Z ECMWF and GEFS Mean have also trended toward a slower solution with the system as it moves from the northern Plains to the Northeast Thursday to Saturday. While the GFS still appears to be a bit too amplified for a period across the northern Plains to the Upper Midwest late Thursday into Friday, its slower timing is now less of an outlier in comparison to the ECMWF, UKMET, Canadian and GEFS Mean. The NAM, which was largely consistent with its previous run, is now along the leading edge of the guidance with the trough as it moves from the Upper Midwest to the Northeast Thursday to Saturday. ....Closed mid level low off the Pacific Northwest coast Thu...moving into the Northern Rockies Fri... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average Model consensus continues to take a closed mid level low from the Pacific Northwest coast Thursday morning, eastward across the Pacific Northwest and northern Rockies on Friday. Some timing/amplitude differences begin to develop as the system moves into the High Plains Saturday morning, but overall models are fairly good agreement with this system through 12Z Saturday. ...Broad mid level trough over northern Mexico Thu/Fri... ...Surface low over eastern NM/west TX Fri... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average Overall, models remain in good agreement -- continuing to show a long wave trough developing over northwest Mexico Thursday night before broadening across northern Mexico into the southern Plains Friday into early Saturday. ...Area of low pressure developing north of the Bahamas by early Saturday ... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average While there are differences in the details, the overnight deterministic guidance was in generally good agreement - indicating an area of low pressure organizing north of the Bahamas by Saturday morning. Pereira Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml