MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1151 AM EST MON NOV 09 2015 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 FORECAST CONFIDENCE... CLOSED LOW OVER CENTRAL PLAINS LIFTING TROUGH OHIO VALLEY TUES AND THROUGH NEW ENGLAND WED WITH ASSOCIATED SURFACE LOW ACROSS GULF COAST REDEVELOPING ALONG THE MID-ATLANTIC COAST WED AND LIFTING NORTHEAST OFFSHORE OF NEW ENGLAND. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM BLEND CONFIDENCE: AVERAGE THE CLOSED LOW CURRENTLY LOCATED IN MO WILL CONTINUE TO LIFT ACROSS THE NORTHERN OHIO VALLEY OR LOWER GREAT LAKES WHILE FILLING...EVENTUALLY SHIFTING EAST. MASS FIELDS ALOFT APPEAR IN FAIRLY STRONG AGREEMENT BUT SIGNIFICANT DIFFERENCES REMAIN PARTICULARLY AT THE SURFACE WITH THE MID-ATLANTIC REDEVELOPMENT AND ASSOCIATED QPF. THIS SPREAD CAN BE SEEN IN MODERATE SPREAD OF THE SURFACE LOW CLUSTER...THOUGH DIFFERENCES IN DEPTH/INTENSITY ARE LIKELY TO BE THE MORE SIGNIFICANT PLAYER. A BULK OF THE ECMWF MEMBERS REMAIN ON THE WESTERN AND NORTHERN PORTION OF THE CLUSTER WITH THE 00Z OPERATIONAL RUN OUTPACING MUCH OF CLUSTER THROUGH 11/00Z WED BEFORE BECOMING MORE CENTRAL BUT SOUTHERN OF ITS ECMWF MEMBERS...AS IT MOVES OUT TO SEA. THE 00Z GEFS MEMBERS WERE THE GENERALLY THE SOUTHERN MEMBERS OF THE SUITE BUT LOCATION IS STRUNG OUT WEST TO EAST ALONG THE CLUSTER WITH THE OPERATIONAL 00Z GFS ALSO LEADING THE GEFS SUITE....THIS MADE THE 00Z GFS AN SOUTHEAST OUTLIER COMPARED TO THE OTHER 00Z RUNS. THE 06-12Z RUNS REMAIN WITH SOLID CONTINUITY OF THIS SOLUTION THIS TREND CONTINUED WITH THE 12Z GFS. THE 12Z NAM CONTINUES IT TREND OF BEING MUCH FURTHER WEST OF THE SURFACE CLUSTER AND DEEPER ALOFT...THIS ALSO PRODUCES SIGNIFICANT DIFFERENCES IN THE QPF...SO PLEASE REFER TO THE QPFPFD FOR FURTHER DETAILS. THE ENSEMBLE MEANS GARNER THE MOST SUPPORT...EXCEPT THE 09Z SREF....WHICH FOLLOWED ITS OPERATIONAL MODEL. THOUGH THE DETERMINISTIC RUNS GENERALLY ON ON THE PERIPHERY OF THE ENSEMBLE CLUSTERS...A BLEND OF THE REMAINING MODELS: 00Z ECMWF/UKMET/CMC AND THE 12Z GFS... ARE SUPPORTIVE OF THE MEANS. THE NON-NAM BLEND IS PREFERRED BUT GIVEN SPREAD AT SUCH A SHORT TIME FRAME BEFORE THE EVENT PARTICULARLY IN QPF/SURFACE TRACK...CONFIDENCE IS WEAKENED TO AVERAGE. DEEP UPPER TROUGH CROSSING THE WESTERN U.S. AND EJECTING INTO THE MIDWEST WED... DEEPENING SURFACE CYCLONE ACROSS THE CENTRAL PLAINS INTO THE GREAT LAKES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: OPERATIONAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE THE DEEP LAYERED TROF CURRENTLY MOVING INTO THE WEST COAST WILL VIGOROUSLY EJECT GOING NEGATIVE TILT ACROSS THE CENTRAL PLAINS INTO THE GREAT LAKES BY THE END OF THE PERIOD PRODUCING A STRONG MID-980 MB SURFACE LOW BY THE TIME IT REACHES THE WESTERN GREAT LAKES BY WED NIGHT/THURS MORNING. MODEL AGREEMENT IS TIGHT BOTH IN TIMING BUT STRENGTH TO SUPPORT THE ENSEMBLE MEANS EVEN REACHING SUB-990MB SURFACE LOWS ACROSS THE MIDWEST AND GREAT LAKES. MINOR DIFFERENCES START TO MANIFEST THURSDAY AFTERNOON/NIGHT...DRIVEN MAINLY BY INTERACTION WITH THE UPSTREAM SHORTWAVE BUT NOT DRAMATICALLY SO. AS SUCH A BLEND OF THE OPERATIONAL MODELS IS PREFERRED AT ABOVE AVERAGE CONFIDENCE. PROGRESSIVE SHORTWAVE REACHING THE PACIFIC NORTHWEST BY WED EJECTING ACROSS THE NORTHERN PLAINS BY THURS NIGHT. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF OPERATIONAL MODELS UNTIL 12/12Z... 12Z GFS/00Z ECMWF/UKMET AFTERWARD CONFIDENCE: SLIGHTLY ABOVE AVERAGE A PROGRESSIVE SHORTWAVE AND ASSOCIATED COLD FRONT CONTINUE TO BE WELL PROGGED CROSSING THE PAC NORTHWEST WED...MOVING INTO THE NORTHERN PLAINS THURS. THE STRONG MODEL AGREEMENT CONTINUES MAINLY THROUGH THURSDAY MORNING...AFTERWARD THE 12Z NAM AND 00Z CMC ARE A BIT MORE AMPLIFIED WITH THE SHORTWAVE AND DOWNSTREAM S/W RIDGE ACROSS LAKE MICHIGAN...THE 00Z UKMET/ECMWF HAVE THE STRONGER CONSOLIDATED LOW BUT A BIT FLATTER ACROSS THE DAKOTAS ALOFT... THE 12Z GFS SPLITS THE DIFFERENCE BUT FAVORS THE FLATTER SOLUTION A BIT MORE. HOWEVER...THE 06Z GEFS WAS A BIT FASTER AND STRONGER WITH THE S/W SO PATTERN MAY BE SHIFTING TOWARD THE STRONGER MORE AMPLIFIED SOLUTION. STILL OVERALL DIFFERENCES ARE SMALL ENOUGH TO CONTINUE AN OPERATIONAL MODEL BLEND PRIOR TO 12/12Z (THURS)...AFTERWARD WILL FAVOR THE 12Z GFS IN A BLEND WITH THE 00Z ECMWF/UKMET AT SLIGHTLY ABOVE AVERAGE CONFIDENCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... GALLINA