Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1138 PM EST Sat Feb 16 2019 Valid Feb 17/0000 UTC thru Feb 20/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation...with Preferences and Confidences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Overall Pattern Across the CONUS... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average Through 20.12z, the general synoptic pattern across the CONUS is expected to feature subtropical ridging over southern Florida with persistent troughing over the western US. As embedded impulses get ejected out in the downstream southwest flow, southerly return flow from the Gulf of Mexico will impinge on a stalled boundary. The result will be multiple rounds of rainfall, some heavy, particularly toward the end of the current forecast period. One shortwave trough will lift from the central Plains into the Great Lakes, opening up as it gets sheared out by early Monday. Another impulse will dig the Western US trough further with that energy eventually translating into the central Plains by mid-week. Finally, another sharp trough will be working into the Pacific Northwest by late Tuesday into Wednesday. Across the central/eastern US, there is above average forecast confidence through mid-week with respect to the large scale mass fields. The current 00z guidance along with the previous 12z guidance available shows good clustering and the operational runs are closely aligned. There are some notable QPF differences across the Deep South, TN and lower OH Valley by Day 3, but the spatial differences are not significant for being Day 3 with relatively similar magnitudes represented in the 6-hourly amounts. The biggest differences seen in the guidance lies across the Pacific Northwest by Tuesday with the sharp shortwave trough digging in. The GFS shows its typical fast bias while the ECMWF/NAM are on the slower side of the model envelope. The UKMET is considerably stronger and also keeps the bulk of the energy offshore. The CMC resembles the ECMWF but shows the timing of the GFS. For this cycle, the preference would be to lean away from the UKMET solution given its significant timing and magnitude differences. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor