Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 329 AM EDT Tue Jun 09 2020 Valid Jun 09/0000 UTC thru Jun 12/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Model Evaluation Including Initial Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Low that spins off trough over the central Rockies and lifts from the central Plains over the Upper Midwest Wednesday into Wednesday night... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General Model Blend Confidence: Average All 00Z guidance slowed the progression of the upper low center that develops and traverses Kansas today. The 00Z NAM is the deepens and thus slowest solution, but not by much. This is a complex interaction between the trough/low and the Cristobal remnants, so the variability can be compromised with a general model blend given there are reasonable solutions among the deterministic suite. The ECMWF is a little slower with the cold front that reaches the Eastern Seaboard Thursday, but for now a general model blend suffices. ...Cristobal Remnants... ~~~~~~~~~~~~~~~~~~ Preference: General Model Blend Confidence: Average The 00Z guidance suite provides a good, tight track window over the next 36hrs as the remnants of Cristobal accelerate north-northeast from south-central MO to the UP and northern Ontario. ...Southern Gulf of Alaska Low Stalling off the BC Coast through Thursday night... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General Model Blend Confidence: Average Good agreement on Day 1 rain which is heaviest of the three days (general onshore flow Days 2/3), but then the 00Z GFS is much more progressive with the trough approaching the West Coast Thursday night while the 00Z ECMWF has slowed with a closed low well off the CA coast Thursday night. These are typical biases (GFS progressive, ECMWF slow), so a general model blend (NAM/UKMET/CMC are all between the ECMWF and GFS), should make for a reasonable compromise in the middle. Jackson Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml