Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1234 PM EDT Sat Oct 12 2019 Valid Oct 12/1200 UTC thru Oct 16/0000 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 12Z Final Model Evaluation with latest Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Deep Plains/Upper Midwest Cyclone ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above average The anomalously deep layer cyclone over the north-central U.S. will gradually weaken as it lifts north/northeast into Canada over the next couple of days. The associated cold front will gradually sweep across the eastern U.S. but is forecast to stall/linger over the Deep South into early next week. The models remain well clustered with the evolution of this system in the next 3 days. A general model blend is preferred. Pacific Northwest to the Northern Plains ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above average A quick moving shortwave trough will drop down through the Canadian Rockies and into the northern Rockies Day 2/3, inducing surface cyclogenesis across the Upper Midwest. The deterministic global models are fairly aligned with the ensemble means, so overall there is above average forecast confidence and a general model blend is preferred. Southwestern U.S. to Four Corners Region ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: ECMWF/UKMET/CMC through 48 hours; ECENS/GEFS means Day 3 Confidence: Average Troughing moving through the western US will eventually pinch off a southern stream shortwave across southern California early Monday. The non-NCEP guidance (ECMWF/UKMET/CMC) are notably more amplified with this feature compared to the GFS and NAM solutions. As the wave moves from the Southwest U.S. toward the Four Corners and central Rockies regions, the GFS and NAM are considerably faster/flatter with the upper level energy. Looking at the ensemble members and means, that scenario is not completely unreasonable and in fact, the deterministic ECWMF is much slower compared to its ensemble mean (and similar to the GEFS mean as well). So, will prefer a blend of the ECMWF/UKMET/CMC initially (through 48 hours) but for Day 3 have a blend of the ECENS/GEFS mean, which will be near the overall model consensus. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Taylor