Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 356 PM EDT Sun Jul 29 2018 Valid Jul 29/1200 UTC thru Aug 02/0000 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 12Z model evaluation...with final preferences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overall Synoptic Pattern across the CONUS... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 12Z GFS/12Z ECMWF Confidence: Slightly above average 19Z update: The 12Z UKMET adjusted enough from its 00Z cycle to be used as part of a blend along and east of the Mississippi River, but remains a bit faster across the Pacific Northwest. The 12Z CMC still looks different with its evolution across the Midwest with a more strongly defined surface low. Meanwhile, the 12Z ECMWF only made minor changes from its previous run across the CONUS. Previous discussion below: Deterministic and ensemble models continue to indicate good overall synoptic scale agreement over the continental U.S. through Wednesday with an upper level trough off the Pacific Northwest Coast, a strong upper level ridge over the Desert Southwest and Great Basin, and perhaps most importantly, an evolving trough and potential closed low over the Midwest states. The main differences up through this time involve smaller scale perturbations moving around and north of the western U.S. ridge likely resulting in some MCS development downstream. Across the central and eastern U.S., the best model agreement along with trends supported a 12Z GFS/00Z ECMWF blend with the 12Z NAM faster/weaker with the core of the upper trough over the Midwest/Upper Midwest, whereas the 00Z UKMET/CMC were either slower and/or deeper with the trough. Across the Pacific Northwest, there was good support for a non 00Z UKMET blend with the UKMET faster with the progression of an upper trough by Wednesday. Elsewhere, a general model blend 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 Otto