Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1249 AM EDT Wed Jul 08 2020 Valid Jul 08/0000 UTC thru Jul 11/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Model Evaluation with Model Preferences/Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Closed low moving east across south-central Canada through Friday Associated cold front crossing the northern Plains Wednesday/Thursday and the Great Lakes Friday ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 12Z ECMWF/CMC with some 00Z NAM/GFS Confidence: Average A slightly negatively tilted trough axis moving out of the Northern Rockies and over southern Alberta tonight will continue to shift east across the Canadian Prairies through Thursday before opening and lifting northeast over northern Ontario on Friday. The 00Z NCEP guidance was a bit faster and the 00Z NAM ended up becoming deeper/slower by Day 2 as the systems makes its way into the northern Plains. The 00Z GFS still slightly outpaces both with trough progression through the Great Lakes Friday/Day 3, but is not too far ahead to be totally discounted, just limited in the blend. The 12Z UKMET is notably flatter than consensus which makes it an outlier. Next trough moving into the Pacific Northwest Thursday ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General Model Blend Confidence: Slightly above average The 00Z NCEP models remained in good agreement with other models from the 12Z cycle with respect to the depth and progression of this feature into the Pacific Northwest late Thursday. No change made to the model preference. Low pressure moving northeast along Eastern Seaboard into this weekend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 00Z NAM and 12Z ECMWF/CMC Confidence: Average A fairly weak cyclone is expected to move drift east-northeast across the Carolinas today before turning northeast up the Eastern Seaboard on Thursday and Friday. At the same time, a mid-level ridge builds to the north of the low across the northern Appalachians and New England. The presence of this ridge continues to suggest a slower solution. The 00Z GFS remained the most progressive guidance with the turn north on Thursday...which was the primary reason that the GFS was not included in the model preference. The 12Z UKMET is a little less deep with the cyclone than the 07/00Z run, but is even slower now and a notable outlier. The 00Z NAM and 12Z ECMWF/CMC remained consistent with their previous runs and were favored. Shortwave trough moving across New England Today ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General Model Blend Confidence: Above average Good agreement with this Day 1 shortwave trough crossing northern New England Wednesday. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml This product will terminate August 15, 2020 with the 21Z issuance: www.weather.gov/media/notification/pdf2/scn20-58pmdhmd_termination. pdf Bann