MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 140 AM EST MON NOV 14 2016 VALID NOV 14/0000 UTC THRU NOV 17/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION INCLUDING PREFERENCE AND FORECAST CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ MID-LEVEL CLOSED LOWS IN THE SOUTHEAST TODAY COMBINING AND LIFTING NEWD SUPPORTING SURFACE LOW DEVELOPMENT MONDAY ALONG THE EAST COAST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS/ECMWF/CMC BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE MODELS HAVE SHOWN VERY LITTLE VARIATION OVER THE LAST FEW CYCLES FAIRLY LOCKED TO THEIR OWN DEVELOPMENTS. THE 00Z NAM LIKE THE 12Z UKMET REMAIN STRONGER WITH THE UPSTREAM WAVE CURRENTLY IN THE OZARKS FAVORING IT WITHIN THE PAIR SLOWING THE LEAD WAVE IN UPSTATE SC. THIS RESULTS IN A SLOWER AND MORE TIGHT/SLIGHTLY INLAND SURFACE WAVE TRACK. THE 00Z GFS LIKE ITS PRIOR RUNS REMAINS ON THE FAR EASTERN SIDE OF THE ENSEMBLE PACKING THOUGH HAS SHIFTED SLIGHTLY EAST TOWARD THE CMC PROVIDING ADDITIONAL OVERALL CONFIDENCE. THE ECMWF PROBABLY SHOWS THE MOST VARIATION FROM PRIOR EC RUNS SHIFTING A BIT FURTHER TO THE COAST YET REMAINS FASTER THAN THE UKMET/NAM IF SLOWING JUST A BIT. THE 12Z CMC/CMCE SEEMS TO SPLIT THE DIFFERENCE OF THE GFS/GEFS AND ECMWF/ECENS MEAN WITHIN THE FAVORED FASTER EVOLUTION...I.E. EASTERN WAVE DOMINANCE IN THE WAVE CONSOLIDATION. BY DAY 3 INFLUENCES OF UPSTREAM SHORTWAVE WILL ALSO IMPACT THIS SURFACE WAVE SO PLEASE REFER TO SECTIONS BELOW FOR ADDITIONAL INFORMATION/PREFERENCE ON THESE INFLUENTIAL SYSTEMS. AS FOR THIS WAVE... AN ECMWF/CMC/GFS BLEND REMAINS PREFERENCE THOUGH WEIGHTED TOWARD THE ECMWF/CMC. 07Z UPDATE: MINOR SHIFTS SEEN IN THE 00Z NON-NCEP SOLUTIONS...REMAINING FAIRLY CONSISTENT WITH THEIR PRIOR RUNS. AS SUCH WILL KEEP INITIAL PREFERENCE 00Z GFS/ECMWF/CMC BLEND. SOUTHERN HALF OF CANADIAN SHORTWAVE DIVING INTO THE SOUTHEAST FILLING OUT THE BASE OF THE EASTERN U.S. TROF BY WED MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-ECMWF BLEND CONFIDENCE: AVERAGE THE BASE ENERGY OF SHORTWAVE CROSSING THE DAKOTAS AT THIS TIME DESCENDS INTO REINFORCE THE EASTERN U.S. TROF ACROSS THE SOUTHEAST INTO PENINSULAR FL BY WED. MODELS ARE FAIRLY TIGHT AGREEMENT THROUGH EARLY TUESDAY BUT AS THE SHORTWAVE FILLS OUT THE BASE...THE 12Z UKMET BECOMES VERY STRONG/AMPLIFIED ACROSS N AL/GA SUPPORTING A TIGHT/CYCLONIC VORT OFF THE CAROLINAS BY WED MORNING. THE 12Z ECMWF IS ALSO STRONG WITH THE WAVE BUT MUCH FURTHER SOUTH INTO THE WESTERN FLORIDA STRAIT. IMPACT TO TIMING/STRENGTH OF THE FRONTAL ZONE CROSSING SOUTH FLORIDA SEEMS MINOR FOR THE ECMWF ESPECIALLY AS IT COUNTERBALANCES THE WEAKER SOLUTION PRESENTED BY THE 00Z GFS. THE UKMET HOWEVER INDICATES A STRONGER SURFACE REFLECTION/QPF SIGNAL AND THOUGH IT IS OFFSHORE WILL KEEP IT FROM THE PREFERENCE AT THIS TIME. AS SUCH A NON-UKMET BLEND IS FAVORED AT SLIGHTLY ABOVE AVERAGE CONFIDENCE (GIVEN THE OTHERWISE HIGHER AGREEMENT OF TIMING/STRENGTH IN THE REMAINING GUIDANCE SUITE. 07Z UPDATE: THE 00Z ECMWF APPEARS TO HAVE A ISSUE WITH A VERY SMALL CONSOLIDATED VORT CENTER THAT REFUSES TO SHEAR IN A FLOW THAT WOULD SUPPORT SUCH...LEADING TO SOME ODDLY SHAPED HEIGHT FIELDS IN THE MIDDLE TROPOSPHERE ACROSS THE OHIO VALLEY TUESDAY AND WED. THIS LEADS TO A SLOWING OF THE WAVE ENERGY REACHING THE BASE OF THE TROF COMPARED TO THE GFS/NAM AND 00Z UKMET WHICH IN TURN LEADS TO AMPLIFICATION AND CONSOLIDATION AS WELL AS STALLING THE FRONTAL ZONE THROUGH THE FL STRAIT. THE 00Z CMC THOUGH NOT HAVING THE SAME ISSUES ACROSS THE OHIO VALLEY...IS SLOWER AND SEEMS TO BE A BIT MORE AMPLIFIED ACROSS THE FL PENINSULA BY WED BUT NOT AS DRAMATIC AS THE ECMWF. ALL CONSIDERED WILL SUPPORT A NON-ECMWF BLEND AT AVERAGE CONFIDENCE WITH THE BASE OF THE TROF. LEAD SHORTWAVE ENERGY INTO BRITISH COLUMBIA TODAY WITH ASSOCIATED COLD FRONT ACROSS THE DAKOTAS BY TUESDAY REJUVENATING UPPER TROUGH ACROSS THE GREAT LAKES BY WED AND SLIDING OFF THE MID-ATLANTIC COAST THROUGH THURS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS/ECMWF BLEND CONFIDENCE: AVERAGE THE TIMING OF SHORTWAVE ENERGY SWINGING THROUGH THE PACIFIC NORTHWEST LATER TODAY RAPIDLY CROSSES THE SOUTHERN ROCKIES AND OVERTOPS THE RIDGE IN THE WESTERN HIGH PLAINS BEFORE SLIDING/SHEARING/ELONGATING SOUTHEASTWARD INTO THE GREAT LAKES LATE TUES/WED. THE 12Z CMC IS A BIT SLOWER BUT ALSO PUMPS THE RIDGE FURTHER NORTHEAST INTO THE WESTERN LAKES FORCING THE TROF FURTHER EAST/NORTH THAN THE REMAINING GUIDANCE. AFTER WED INTO THURSDAY GUIDANCE FURTHER SPLITS IN TIMING/CONSOLIDATION OF THE LEADING EDGE OF SHORTWAVE ENERGY. THE 12Z UKMET IS A BIT FASTER/FURTHER NORTHEAST AND DOES NOT BEGIN TO CLOSE OFF A WAVE ALONG THE MID-ATLANTIC/CAROLINA COAST ALOFT LIKE THE SLOWER 12Z ECMWF DOES. THE 00Z NAM WHICH HAS A CONSOLIDATION BIAS BY DAY 3 FAVORS THE 12Z ECMWF SOLUTION IN CLOSING THE LOW OFF BY THE END OF THE FORECAST PERIOD. THE 00Z GFS IS A BIT FASTER AND SPLITS THE DIFFERENCE OF THE UKMET AND NAM/ECMWF SOLUTIONS THOUGH HAS TRENDED A BIT SLOWER AND MORE CONCENTRIC VORT SIGNAL LIKE THE NAM/ECMWF JUST AT A SLOWER EVOLUTIONARY PACE AND FURTHER NORTHEAST. THE 12Z ECENS MEAN AND 18Z GEFS ARE MORE SUPPORTIVE OF THE GFS SOLUTION. GIVEN THE TRENDS WILL FAVOR THE 00Z GFS AS A COMPROMISE BETWEEN THE CONTINUITY AND THE NAM/ECMWF SOLUTIONS...WILL INCLUDE SOME 18Z GEFS/12Z ECENS MEAN BLEND INTO THE PREFERENCE TO HANDLE SOME OF THE OVERALL SPREAD AND KEEP SOME ROOT IN CONTINUITY. CONFIDENCE IS AVERAGE. 07Z UPDATE: THE 00Z CMC CONTINUES TO BE SLOWER AND THEREFORE MORE PROGRESSIVE ACROSS THE GREAT LAKES WITH LIMITED SHEARING ENERGY TOWARD THE CAROLINA COAST...WELL OUT OF PHASE BY THE END OF THE FORECAST PERIOD. THE 00Z UKMET BEING A BIT FASTER THROUGH SOUTHERN CANADA BUT SLOWER ACROSS NEW ENGLAND WITH THE DOWNSTREAM WAVE...SHOWS STRONGER INTERACTION DRAWING ENERGY EASTWARD AND CLOSING OFF THE UPPER LOW NEAR NEW ENGLAND. THE 00Z ECMWF HOWEVER TRENDED TOWARD GOOD AGREEMENT IN TIMING/PLACEMENT AND STRENGTH OF THE SHEAR AXIS WITH THE INITIAL PREFERENCE OF THE GFS. THIS WAS FURTHER SUPPORTED BY THE GEFS SOLUTIONS TO BUILD CONFIDENCE IN SUPPORTING A 00Z GFS/ECMWF BLEND FOR THIS SYSTEM AT AVERAGE CONFIDENCE. SHORTWAVE AMPLIFYING INTO THE PACIFIC NORTHWEST TUES/WED SETTLING INTO THE INTERMOUNTAIN WEST BY THURS...SUPPORTING LEE SURFACE CYCLOGENESIS ACROSS CO/KS BY WED EVENING/THURS. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-GFS BLEND BUT WEIGHTED CLOSEST TO 00Z UKMET. CONFIDENCE: BELOW AVERAGE AN UNUSUAL CONFIGURATION OF MODEL SOLUTIONS CONTINUES AS THE 00Z GFS LIKE ITS PRIOR RUNS AND BULK OF GEFS SOLUTIONS IS SLOW AND THEREFORE BECOMES MUCH STRONGER EVEN CLOSING OFF A LOW ACROSS THE GREAT BASIN BY THURSDAY WITH SOME NEGATIVE TILTING/BROAD DIFFLUENT PATTERN OVER THE CENTRAL ROCKIES SUPPORTING DEEP SURFACE WAVES IN UT AND DEVELOPING IN KS/CO. THIS IS COUNTED BY THE ECMWF/ECENS SOLUTION THAT IS GENERALLY SHALLOWER/FASTER IN CROSSING THE GREAT BASIN INTO UT/W WY BY THURSDAY. INTERESTINGLY THE 12Z ECMWF IS SLOWER THAN THE ECMWF MEAN AS WELL...MUDDYING THE SITUATION. THE 12Z CMC IS IN A TRADITIONAL POSITION FAVORING THE SLOWER MEMBER WITH FAIRLY GOOD CONTINUITY AND ALIGNMENT WITH ITS CMCE MEAN BUT SHOWS MORE OF A NEUTRAL TILT TO THE TROF OVERALL. THE NEUTRAL TILT IS FURTHER SUPPORTED BY THE OTHER MIDDLE GROUND SOLUTIONS OF THE 00Z NAM AND BROADER WAVELENGTH PRESENTED IN THE 12Z UKMET. MUCH OF THE MODEL SPREAD SEEMS TO BE RELATED TO THE TIMING WHICH CAN BE TIED TO THE FILLING OF THE DEEP UPPER LOW CURRENTLY OVER THE GULF OF ALASKA. THE 00Z GFS DID SHOW A SLIGHT EASTWARD DRIFT FROM THE 18Z AND 12Z RUNS THOUGH BOTH WERE ON THE WESTERN FRINGE OF THE ENSEMBLE SUITE OVERALL. DAY TO DAY TRENDS IN THE ENSEMBLE SUITE CONTINUE TO SHOW A BROADENING BETWEEN THE SOLUTIONS AS WELL PROVIDING REDUCED CONFIDENCE OVERALL. CONTINUITY WOULD FAVOR THE ECMWF SOLUTION TOO...SO WILL HEDGE THIS DIRECTION BUT INCLUDE THE 00Z NAM/UKMET/CMC AT HIGHER WEIGHTING THAN THE ECMWF. CONFIDENCE IS BELOW AVERAGE. 07Z UPDATE: THE 00Z ECMWF REMAINS THE FASTEST WITH LITTLE CHANGE IN TIMING/STRENGTH BUT A BIT LESS NEGATIVELY TILTED THROUGH EARLY THURSDAY...BUT ALSO GAINED A TRADITIONAL PATTERN...THE 00Z CMC WHICH MATCHES VERY WELL ALOFT THROUGH SUPPORTS A MUCH STRONGER AND FURTHER NORTHEAST SURFACE REFLECTION BY THURSDAY ACROSS NEB...WHICH LOOKS A BIT SUSPICIOUS. THE 00Z UKMET TRENDED SLIGHTLY FASTER BUT NEARER THE ECMWF. THIS FURTHER SUPPORTS VERY LITTLE FAVOR IN THE SLOWER SOLUTION OF THE GFS EVEN THOUGH THE 00Z GEFS SOLUTIONS ARE VERY TIGHTLY CLUSTERED TO IT. OVERALL THIS KEEPS CONFIDENCE LOW...BUT SLIGHTLY BETTER IN FAVORING A UKMET WEIGHTED NON-GFS BLEND. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... GALLINA