Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 234 PM EST Mon Nov 04 2019 Valid Nov 04/1200 UTC thru Nov 08/0000 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... ...12Z Model Evaluation with Preferences and Confidence... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overall Pattern Across the CONUS through 08.00Z ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average 19Z update: Not much significantly different with the rest of the 12Z guidance now available. The non-NCEP guidance still is a bit more progressive shearing out the closed low over the southwest U.S. into the southern/central Plains but the spread is lowered compared to previous runs. By 84 hours, there is not too much difference in the overall pattern, showing the trough axis through the Great Lakes and ridging anchored along the western U.S. The WPC preference for a general model blend remains. ---previous discussion--- Overall, model agreement is above average for the CONUS through the next 84 hours (08.00Z) with longwave troughing encompassing much of the central/eastern CONUS with embedded shortwaves moving through the flow through the early/mid part of the week. Currently, a weak closed upper level low lies just south of the southern California coast, drifting eastward slowly. In the next 48 hours, this feature is expected to gradually shear out and open up as it becomes absorbed into the northern stream troughing. While the latest guidance is in relatively good agreement, there remains some differences to note. The GFS/NAM continue to be the slower, more closed solution while the non-NCEP guidance is a bit more progressive through 60 hours. As some of this energy becomes absorbed into the northern stream trough, some amplification and negative tilting combined with right entrance region dynamics favors cyclogenesis in the vicinity of the Northeast U.S. by the end (but more so just beyond the forecast period). As such, a general model blend can be employed with slightly above average confidence throughout the forecast period across the CONUS. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Taylor