Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 304 AM EDT Thu Jun 11 2020 Valid Jun 11/0000 UTC thru Jun 14/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Final Model Evaluation Including Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Shortwave and associated surface low lifting into Canada tonight... ...Deepening eastern CONUS trough and cold front through Friday night... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General Blend through Friday ECENS/GEFS from Saturday into Early Sunday Confidence: Average Run to run consistency in the NCEP and non-NCEP guidance from 11/00Z continues to be at a premium...especially across the Ohio Valley and the eastern Great Lakes from late Friday into Saturday and across much of the Northeast and Mid-Atlantic region by early Sunday. It appears that most of the problems in the east revolve around each model's handling of energy dropping southward from Canada into the Great Lakes. The ECMWF/GFS/UKMET each tends to form smaller, discrete lows/circulation centers which rotate around a common gyre...although position and depth of each feature in each of the models can be significantly different from other models. For the moment, the previous idea of leaning on a general model blend into Friday before shifting over to a ECENS/GEFS mean for position and depth of the larger-scale trough still seems reasonable...especially as the deterministic guidance struggles with predictability. ...Longwave trough off the West Coast and shortwave lifting onshore California by the weekend... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: Non GFS Confidence: Slightly Below Average The latest runs of the GFS remain a fast/progressive outlier...but overall think the model clustering that developed in model runs from 12 hours ago is still a better/more viable option at this point...especially with respect to the timing of the low off the BC coast. Using the GEFS mean still seems reasonable through 48 to 60 hours. Thereafter, the CMC becomes a strong outlier with the amplitude of the shortwave as it pivots into the Great Basin Saturday, leaving the ECENS/ECMWF/NAM/UKMET/GEFS as the preferred blend. Bann Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml