Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1249 AM EDT Thu Oct 17 2019 Valid Oct 17/0000 UTC thru Oct 20/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation with Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Great Lakes closed low transferring to developing Northeast coastal surface Low ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above average Very good agreement now with the synoptic evolution of the deep/anomalous storm system affecting the Northeast U.S. tonight. Secondary low along coast will become parent low and deepen tonight and Thursday morning with the system becoming stacked later Thursday and Thursday night. There is excellent, above average agreement with the low position, strength, and track through the next few days such that a general model blend is acceptable and the preferred blend. Developing area of low pressure in the Gulf ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: ECMWF/CMC with some weighting toward NAM Confidence: Below average Broad area of low pressure located over the Bay of Campeche continues to show increased shower and thunderstorm activity per satellite IR imagery in the last 6-12 hours. This system is expected to gradually move northward and then northeastward over the next day or so as it interacts with a weak mid-level shortwave vort over Texas. Models have come into slightly better agreement with the idea that the broad area of low pressure will begin to move northward, but there remains quite a bit of spread in the eventual track and intensity as it approaches the central Gulf Coast by this weekend. The 00Z GFS remains a fast outlier and should be largely discounted. The 00Z NAM matches fairly well with the 12Z ECMWF/CMC with speed/position of the low as it crosses the Southeast U.S., though it is too deep compared to the rest of the guidance. The 12Z UKMET was discounted as it was too deep/strong given as the low tracked off the North Carolina coast, and the latest 0Z UKMET remains fast and too strong (similar to GFS). Its solution remains discounted for now. All told, the ECMWF/CMC track remains the closest to the consensus approach and its solutions are preferred at this time. Forecast uncertainty is high, especially by Day 2/3. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Taylor