Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 331 AM EDT Wed Jun 10 2020 Valid Jun 10/0000 UTC thru Jun 13/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Final Model Evaluation Including Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Low shifting northeast from eastern Kansas, crossing the Great Lakes tonight and merging into a low over northern Ontario through Thursday... ...Associated cold front moving across the eastern CONUS, reaching the Eastern Seaboard Friday... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 00Z ECMWF/UKMET Confidence: Average Good enough agreement on the initial low over eastern KS swinging northeast through the Great Lakes through tonight. Phasing then takes place with Cristobal remnants over northern Ontario and the trailing trough that swings across the Great Lakes and eastern Ontario has divergent solutions on Day 3. Meanwhile there is generally good agreement on the cold front pushing east across the eastern CONUS tonight, stalling near the Eastern Seaboard Thursday. The 00Z NAM and GFS are the most progressive with the Great Lakes trough and the 00Z CMC is farther east with the ridge axis up the Plains. The 00Z greatly slowed its progression of the Great Lakes trough, but the stronger and farther east ridge discourages Day 3 precip over the Great Lakes. The 00Z ECMWF and UKMET are in good agreement with all components of this system including the degree of positive tilt to the Great Lakes trough and are therefore preferred. ...Closed low off British Columbia and associated longwave trough digging and reaching the West Coast by Friday night... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: Non-GFS 00Z General Model Blend Confidence: Slightly Below Average 00Z Guidance generally became more progressive with the reinforcing wave that digs a trough off the CA coast through Thursday and shifts onshore Friday night. The 00Z GFS remains the fastest solution with the most open wave that quickly ejects across the Great Basin Friday night which is well ahead of the 00Z GEFS mean. The 00Z UKMET is the next most progressive (and similar to the 00Z GEFS mean), followed by the similar timing of the 00Z NAM/CMC/ECMWF though the ECMWF is less amplified than the NAM and CMC. In fact, the 00Z ECMWF make quite a shift from having a slow, closed low to a much faster open wave. An indication of the uncertainty with this trough arrival. The Day 3 precip pattern is affected by the timing and depth of the wave with the deeper NAM/CMC similar and the more open and faster UKMET/ECMWF/GEFS also similar and the GFS ahead of everybody. As of now a compromise between the NAM/CMC and ECMWF/UKMET/GEFS camps is reasonable. Jackson Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml