MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 128 AM EST MON NOV 03 2014 VALID NOV 03/0000 UTC THRU NOV 06/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION...INCLUDING THE NAM/GFS/UKMET/GEM AND THE ECMWF ...SOUTHWEST U.S. TROUGH IMPACTING THE SOUTHERN PLAINS AND LOWER MS VALLEY... PREFERENCE: BLEND OF 00Z UKMET/00Z GEM AND 00Z ECMWF CONFIDENCE: SLIGHTLY ABOVE AVERAGE A POSITIVELY TILTED TROUGH AND ASSOCIATED FRONTAL ZONE IS EXPECTED TO PROMOTE A WIDESPREAD RAINFALL EVENT ACROSS A LARGE PORTION OF THE SOUTHERN PLAINS AND INTO THE LOWER MS VALLEY REGION TUES AND WED. THE LATEST GUIDANCE SUPPORTS A WELL-DEFINED MID TO HIGH LEVEL MOISTURE FEED DEVELOPING AND AIMING FOR THIS REGION FROM THE EASTERN PACIFIC OCEAN WHICH IS EXPECTED TO BE AIDED BY THE NORTHWARD ADVANCE OF HURRICANE VANCE SOUTH OF MEXICO OVER THE NEXT COUPLE OF DAYS. THE AFOREMENTIONED TROUGH WILL BE INTERACTING WITH THIS FEED OF MOISTURE ALONG WITH AN ADDITIONAL LOW LEVEL MOISTURE TAP FROM THE WESTERN GULF OF MEXICO. THE LATEST GOES-SOUNDER TPW IMAGERY ALREADY CONFIRMS THE SET UP OF BOTH STREAMS OF MOISTURE. THE MODELS THOUGH ARE STRUGGLING WITH THE MASS FIELD EVOLUTION OF THE UPPER TROUGH. THE 00Z NAM IS MORE PROGRESSIVE WITH THE TROUGH AXIS AND SUGGESTS MUCH MORE ENERGY ADVANCING INTO THE LOWER MS VALLEY BY LATE TUES AND WED...WHEREAS THE 00Z ECMWF/00Z GEM AND 00Z UKMET ARE SLOWER AND DEEPER...AND SUPPORT THE IDEA OF MUCH MORE ENERGY SETTLING ACROSS THE UPPER RIO GRANDE VALLEY AND INTO NORTHERN MEXICO. THE 00Z GFS HAS TRENDED SLOWER AND FAVORS THE NON-NCEP MODEL THEME OF BEING SLOWER...BUT THE GFS IS STILL EAST OF THE NON-NCEP MODEL CONSENSUS BY THE END OF THE PERIOD WITH ITS ENERGY. THE LATEST GEFS MEAN AND ECENS MEAN FAVOR A SLOWER NON-NCEP CONSENSUS. BECAUSE THE NAM IS FASTER WITH THIS ENERGY...IT SUPPORTS A BIT STRONGER SURFACE LOW DEVELOPMENT OVER THE LOWER MS VALLEY INVOLVING A FRONT THAT WILL HAVE SETTLED SOUTHEAST OVER THIS REGION. THE GLOBAL MODELS ARE OTHERWISE ILL-DEFINED WITH ANY WAVE ACTIVITY HERE. BASED ON THE LATEST TRENDS AND ENSEMBLE CLUSTERING...A CONSENSUS OF THE NON-NCEP MODELS WILL BE PREFERRED. ...LEAD NORTHERN STREAM WAVE CROSSING THE MIDWEST/GREAT LAKES THROUGH TUES... ...ASSOCIATED COLD FRONT PUSHING TOWARD THE LOWER MS/OH VALLEYS... PREFERENCE: BLEND OF THE OPERATIONAL MODELS CONFIDENCE: ABOVE AVERAGE THE MODELS ARE WELL CLUSTERED AND SHOWING LITTLE RUN TO RUN VARIATION WITH THIS SYSTEM. ...SHORTWAVE TROUGH CROSSING THE PACIFIC NORTHWEST AND NORTHERN ROCKIES TUES/WED... ...AMPLIFYING TROUGH OVER THE MIDWEST WED/THURS... ...DEEPENING SURFACE LOW CROSSING THE MIDWEST... PREFERENCE: 00Z GFS CONFIDENCE: AVERAGE THE MODELS SHOW A PROGRESSIVE SHORTWAVE TROUGH AND ASSOCIATED JET STREAK THAT CROSSES THE PACIFIC NORTHWEST AND NORTHERN ROCKIES THROUGH TUES. THE ENERGY IS THEN FORECAST TO AMPLIFY AND DIG AGGRESSIVELY SOUTHEASTWARD INTO THE MIDWEST BY WED ALONG WITH AN AREA OF LOW PRESSURE THAT INTENSIFIES TOWARD LAKE MI EARLY THURS. THE 00Z NAM IS THE SLOWEST MODEL WITH THIS TROUGH AMPLIFICATION INTO THE MIDWEST. THE 00Z GFS/00Z ECMWF/00Z UKMET AND 00Z GEM ARE ALL CLUSTERED AROUND A SOMEWHAT FASTER SOLUTION. REGARDING THE LATITUDE OF THE LOW TRACK...THE 00Z UKMET IS THE FARTHEST NORTH...WITH THE 00Z ECMWF THE FARTHEST SOUTH. THE 00Z GFS AND 00Z GEM SPLIT THE DIFF...BUT OVERALL THE SPREAD WITH LATITUDE IS NOT THAT LARGE. THE 00Z GFS WILL BE THE PREFERENCE AS IT BASICALLY REFLECTS THE GLOBAL MODEL CONSENSUS. ...NEXT TROUGH APPROACHING THE PACIFIC NORTHWEST BY LATE WED... PREFERENCE: BLEND OF THE 00Z ECMWF AND 00Z GEM CONFIDENCE: AVERAGE THE NEXT IN A SERIES OF PROGRESSIVE SHORTWAVE TROUGHS WILL ENCROACH ON THE PACIFIC NORTHWEST BY LATE WED. THE 00Z NAM AND 00Z GFS ARE A LITTLE MORE PROGRESSIVE WITH THIS NEXT SYSTEM...WITH THE 00Z GEM/00Z ECMWF AND THE 00Z UKMET ALL A LITTLE SLOWER. THE 00Z UKMET IS ACTUALLY THE SLOWEST SOLUTION AND HAS TRENDED AS SUCH WITH THE 00Z CYCLE. BASED ON STRONGER MODEL CLUSTERING AND THE OVERALL SPREAD OF SOLUTIONS...A BLEND OF THE ECMWF AND GEM WILL BE PREFERRED AT THIS TIME. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON