Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 151 AM EST Fri Feb 14 2020 Valid Feb 14/0000 UTC thru Feb 17/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation with preferences & confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Central and Eastern CONUS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above Average 07Z update: No significant changes noted with the rest of the 00Z guidance and the original model blend preference remains. Relatively quiet synoptic pattern expected across the CONUS through the next 3 days. Initially the flow will dominated by a large Arctic high pressure moving from the Upper Midwest toward the Ohio Valley through Friday. This will continue to shunt the slow moving, lingering warm conveyor/frontal zone across the far eastern US. Overall, the latest (14.00Z) guidance remains in excellent agreement with the progression of this feature such that a general model blend for day 1. A secondary shortwave trough clips the northern Plains and Great Lakes region which should pass without much activity other than to reinforce some of the Arctic air and a continuation of the lake effect snows. As such, with the favorable model agreement and relative quieter pattern, a general model blend can be used for the central and eastern CONUS. Pacific Northwest Shortwave Day 3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: ECENS/GEFS mean blend Confidence: Below average 07Z update: The 00Z ECMWF/CMC/UKMET did not offer any better consensus to the shortwave progression on day 3 and it still shows quite a bit of variability in timing and amplification across the Pacific Northwest. The 00Z NAM now appears too amplified and the 00Z ECMWF is uncharacteristically fast. Given the higher than usual variability, a solution geared toward the ECENS/GEFS means seems appropriate for day 3. A compact but amplified shortwave trough will cross through the Gulf of Alaska toward southern BC and Washington State on Day 3. There remains some sizable timing differences due to amplification of upstream ridging in its wake. The UKMET is slower and more amplified while the CMC is flatter and more progressive. This puts the ECMWF/GFS in the middle ground yet these models are also showing some differences, where the GFS is a bit slower than the ECMWF. The 00Z NAM also could be included in a blend with its similar solution to the GFS and ECMWF at this point. Overall, due to these timing differences model forecast confidence is at slightly below average. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor