Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1131 AM EST Thu Dec 12 2019 Valid Dec 12/1200 UTC thru Dec 16/0000 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 12 UTC Model Evaluation with Preferences and Forecast Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overall Pattern Across the CONUS... Preference: General model blend (less weight toward 12Z GFS east coast) Confidence: Average Mid/upper level trough axis currently over the central U.S. will move eastward and amplify this weekend. Surface low will develop across the Gulf Coast and lift along the eastern seaboard, taking an interior track. Overall, model guidance shows average clustering with the low tracks and with minor ensemble spread through 60 hours. The 12Z GFS trough axis swings through the East Coast a bit faster than the rest of the guidance, and is not favored as much through 48 hours. In its wake, cold Canadian high pressure builds across the northern tier while another shortwave trough tracks across the west coast and Rockies. Here, model agreement is fairly high such that a general model is preferred. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor