Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 241 AM EDT Fri Jul 26 2019 Valid Jul 26/0000 UTC thru Jul 29/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation, Including Final Confidence and Preferences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Northern Tier of the U.S... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: non 00Z GFS blend Confidence: Average ...07Z update... The 00Z UKMET slowed down its progression to be closer to the remaining model consensus Sunday into Monday across the Dakotas. Therefore, it has been added to the preference. Outside of this adjustment in the 00Z UKMET, no significant differences were noted with the 00Z UKMET/CMC/ECMWF compared to their previous 12Z cycles. ...previous discussion follows... Two shortwaves will track across southern Canada from west to east through Sunday night. The first shortwave entering Manitoba early this morning shows no significant differences as it tracks into Ontario and Quebec over the weekend. The timing has gotten better regarding a second shortwave to enter Saskatchewan Saturday night compared to yesterday's guidance. While timing of this second wave has gotten better, the 00Z GFS is weak with a mid-level vort and low level wave to the south of the Canadian shortwave over the Dakotas. The 12Z UKMET is slightly quicker than the consensus leaving the 00Z NAM, 12Z ECMWF and 12Z CMC is good agreement with the ensemble means while carrying good run to run consistency. ...Remainder of the CONUS including the Southwest... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Slightly above average ...07Z update... No major changes were noted in the 00Z ECMWF/UKMET/CMC compared to their previous 12Z cycles. ...previous discussion follows... No significant mass field differences were noted with the southwestern ridge and some of the more significant vorticity maxima revolving around the center of the ridge. Regarding the remainder of the U.S., similarly, no significant mass field differences were noted in the latest guidance. Model trends at www.wpc.noaa.gov/html/model2.html 500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml Otto