Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 243 AM EDT Wed Jul 31 2019 Valid Jul 31/0000 UTC thru Aug 03/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation and Final Preferences/Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overview of the CONUS features... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Average ...07Z update... Enough nudges were made with the 00Z UKMET/CMC concerning mid-level vorticity Thursday into Friday toward the remaining model consensus to include them as part of the preference. Little changes were noted with the 00Z ECMWF compared to its previous 12Z cycle. Therefore, a general model blend is recommended. ...previous discussion follows... Mid-upper level troughing will remain on either side of a nearly stationary ridge centered over NM through Saturday morning. A trough located east of the Mississippi River has two components, one over southeastern Canada and a southern portion near the central Gulf Coast into the Gulf of Mexico, with forecasts showing slow eastward progression with the northern stream component. Meanwhile, a closed low just west of the British Columbia coast will slowly move inland Wednesday night while a second shortwave/small closed low will strengthen to its southwest and near the coasts of Washington Thursday night. There is decent agreement with the large scale features across the CONUS but the 12Z CMC is significantly slower with a shortwave, which originates across the Southwest today, as it tracks around the southwestern ridge into the Great Plains. Among the remaining 00Z NAM, 00Z GFS, 12Z ECWMF and 12Z UKMET, the 12Z UKMET has some differences with its handling of the mid-level shortwave over the Midwest Friday into Saturday. Some north/south differences continue with a surface low in Kansas and Oklahoma, but ensemble spread is a bit larger today beyond 12Z/02 which lowers confidence somewhat. While agreement outside of the 12Z CMC is relatively good, the 12Z ECMWF, 00Z NAM and 00Z GFS show the best agreement with the ensembles and their previous runs. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Otto