Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 132 AM EST Mon Nov 11 2019 Valid Nov 11/0000 UTC thru Nov 14/1200 UTC ..See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... ...00Z Model Evaluation with Final Preferences and Confidence... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Amplifying mid-level trough into the north-central U.S./Great Lakes today/tonight... ...Surface low in the vicinity of New England Tuesday morning... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above Average The 00Z UKMET adjusted slower for Tuesday with its mid-level trough progression, toward the remaining model consensus compared to its 12Z cycle. Therefore, given the good agreement with all of the available models, a general model blend is preferred. ...Cold front nearing the Pacific Northwest on Tuesday and accompanying shortwave into the Great Plains on Wednesday... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average The latest deterministic models are in fairly good agreement with a cold front into the Pacific Northwest and the corresponding shortwave downstream into the Great Plains on Wednesday. While some minor timing differences regarding the mid-level shortwave show up by Thursday morning with the 00Z GFS fastest, the differences are small enough though that time to support a general model blend. ...Closed low currently over the Baja Peninsula... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: non 00Z NAM blend Confidence: Average While a subtle trend to be faster has been noted in the ensembles Thursday morning, the 12Z UKMET remains faster than a majority of the latest models. The 00Z UKMET slowed down enough to be included as part of a blend while the 00Z ECMWF sped up slightly from its 12Z cycle. The 00Z NAM was slightly slower with the 00Z GFS by Thursday morning while the CMC remained consistent. The 00Z NAM is the only model to stand out enough to exclude it from the preference. ...Weakening shortwave trough approaching California mid-week... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly below average Timing differences with this shortwave are prevalent in the ensemble members. Trends from the 00Z ECMWF/UKMET/CMC were toward the middle of the ensemble spread and while the 00Z NAM/GFS were toward the quicker side of the guidance, the faster trends in some of the non NCEP guidance supports a general model blend at this time. However, ensemble spaghetti heights show enough spread to lower confidence below average for now. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Otto