Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 214 PM EST Sat Nov 09 2019 Valid Nov 09/1200 UTC thru Nov 13/0000 UTC ..See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... ...12Z Model Evaluation with Preferences and Confidence... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Amplifying mid-level trough axis into the north-central U.S. for Monday... ...Surface low in the vicinity of New England Tuesday morning... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 00Z ECENS/12Z GFS blend Confidence: Average 19Z update: The biggest question marks remains to be the low track across New England on Day 3. The 12Z ECMWF continues to be the western solution, with its low more inland, while the rest of the deterministic guidance takes the low offshore. The ECENS is to the right of the deterministic run and closer to the operational GFS and GEFS, so the preference will be toward the ECENS/GFS/GEFS solution for now. ---previous discussion--- Anomalous trough axis will amplify over the north-central U.S. and move across the Great Lakes through mid-week. The most recent cycle of the models shows fairly good agreement in the strength, position, and timing of the trough axis, with the CMC a bit slower compared to the GFS/NAM/ECMWF. A surface low will develop near the Mid-Atlantic and move along the Northeast and New England coasts. The NAM is the fastest with its low track while there is reasonable agreement now between the GFS/ECMWF (though the ECMWF is inland while the GFS is just offshore). A blend of the GFS/ECMWF yields a solution close to consensus and is preferred at this time. ...Cold front nearing the Pacific Northwest on Tuesday... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: 12Z GFS/NAM, 00Z CMC Confidence: Slightly above average A weak shortwave trough will push into the Pacific Northwest Tuesday into Wednesday. Overall, timing between the various models is fairly similar with the 00Z ECMWF slightly ahead of the GFS/NAM/CMC. As such, the best consensus and model trends suggest a GFS/NAM blend with some incorporation of the CMC is sufficient. ...Closed low over northwestern Mexico... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Average The most recent model guidance is in above average agreement with little spread throughout the next 3 days as a closed upper level low currently off the Baja of California drifts eastward. The consensus is for this feature to remain removed from the northern stream energy through 84 hours as it approaches western Mexico. A general model blend is sufficient for this feature. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Taylor