Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 235 AM EST Thu Feb 07 2019 Valid Feb 07/0000 UTC thru Feb 10/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation...with Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 08z update: Overall, with the rest of the 00z model guidance now available, there continues to be above average model agreement through 84 hours. With the system across the central/eastern US lifting quickly through in the next 24 to 36 hours, a general model blend for the mass fields will be sufficient. There is now better agreement with the timing of the stronger shortwave dropping through Washington Friday night into Saturday. The UKMET is a touch fast, but the rest of the guidance is well clustered. A general model blend of the 00z guidance will be preferred. ...Central/Eastern US... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend, led by the 12z ECMWF Confidence: Above average There is above average model agreement across the central/eastern US with respect to the mass fields through the next 84 hours. Current shortwave trough digging across the southern Rockies will lift northeast through the central US into the Great Lakes by Friday, then will close off over the Hudson Bay region. All of the latest deterministic and ensemble guidance is well clustered at the 500 mb heights. At the surface, a wave of low pressure will develop across the southern Plains then quickly lift into Michigan by Thursday night. Again, there is very good agreement in the models with its track and speed. Overall, minor QPF differences exist along and ahead of the low track across the TN, OH Valleys and lower Great Lakes. But in general there is decent spatial agreement. As a result, a general model blend will be sufficient. ...Western US... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend, led by the 18z/00z GFS Confidence: Slightly above average A pair of closed mid/upper level lows will drop through the western US during the forecast period. The first, currently near 130W/40N, will drop southeast toward the central California coast before weakening and opening up inland. There is fairly good agreement for this feature, though the CMC is a tad faster, while the UKMET is weaker/flatter and the NAM on the stronger side. A general model blend for that feature would likely yield a good approach. A much stronger closed low is expected to form across B.C. Friday night then drop south in Washington or just offshore. There are some timing differences with the CMC/ECMWF on the faster side compared to the slower GFS. The speed differences become more pronounced toward th end of the forecast period Saturday into Saturday evening as the ECMWF continues to be faster than the GFS. The WPC preference will be for a general blend, leaning toward the GFS for the western US. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor