Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 246 PM EDT Thu Jul 04 2019 Valid Jul 04/1200 UTC thru Jul 08/0000 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 12Z Model Evaluation...with Final Confidence and Preferences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overall Pattern Across the CONUS... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend; lesser weight toward the 12Z UKMET Confidence: Slightly above average --19Z Update-- Upon reviewing the latest guidance, the 12Z EC/CMC/UKMET, previous thinking still remains in regards to the general model blend with a bit of caution when using the UKMET, especially later in the period. --Previous Discussion-- Troughing across the western CONUS will continue through Day 3 thanks to ongoing ridging along the Gulf of Alaska. Meanwhile, the ridge across the east coast will start to erode as mid-level vorticity ejects from the western trough. Given this, expect organized convection to be primarily focus across the Plains into the Mid/Upper MS Valley. However, by Day 3, the mid/upper levels in the northeast will become more zonal as the ridge begins to diminish allowing mid-level energy to interact with a surface cold front. Models are in fairly good agreement from a mass field perspective. However, the 00Z UKMET is once again showing signs of height, temperature and mid-level vorticity discrepancies compared to model consensus. It appears the UKMET is too amplified with its mid-level ridging across the Plains and low level trough axis toward the end of the period. In addition, the 500mb heights are questionable in the east given the weaker mid-level vorticity ejecting from the western trough. These variations are reflected by the more significant QPF differences. Therefore, lesser weight was given toward the UKMET overall. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Pagano