Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1237 AM EDT Tue Jun 23 2020 Valid Jun 23/0000 UTC thru Jun 26/1200 UTC ...See NOUS42 KWNO (ADMSDM) for the status of the upper air ingest... 00Z Model Evaluation Including Preferences and Forecast Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Closed low over Ontario/Quebec Shortwaves over the lower MS/OH Valleys ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Average The large closed upper low over western Ontario is expected to slowly advanced eastward over the next 3 days, settling into western Quebec by the end of the forecast period. In the synoptic sense, all the models show average to above average consistency and agreement from the past few runs. The main differences lie on the periphery of the troughing where multiple convectively induced shortwaves push across the central Plains to MS River Valley and into the Ohio Valley. A general model blend suffices from a mass field synoptic sense but more mesoscale driven differences including QPF can be expected however. Troughs approaching British Columbia and Pacific Northwest ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: UKMET/GFS/NAM blend Confidence: Average Shortwave trough energy will move through Pacific Northwest into the central/northern Rockies over the next couple of days, with a more significant shortwave trough approaching the region on Wednesday night into Thursday. As has been the case the last several runs, the ECMWF has shown a flatter, more progressive flow pattern that is out of sync with the rest of the deterministic guidance which advertises a slower, more amplified trough that digs over the Rockies into the day 3 period. Meanwhile the GFS remains a slower solution and has strong support from its ensemble mean as well. While the UKMET/NAM offer a middle ground solution, they do lean toward a slower approach similar to the GFS, leaving the ECMWF as more an outlier at this time. Mid-level energy lingering over the lower MS Valley/Texas ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average Lingering upper level energy that is expected to become removed from the westerlies will slowly meander over the lower MS River Valley and Texas areas while toward the day 2/3 time frame, weak tropical energy from the western Gulf approaches TX/LA. Much of the model differences will lie in the mesoscale sector but on a synoptic scale a general model blend suffices. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor