MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 311 AM EDT SAT JUN 06 2015 VALID JUN 06/0000 UTC THRU JUN 09/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION INCLUDING FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SURFACE LOW OFFSHORE OF MID-ATLANTIC CANADIAN COLD FRONT CLIPPING NEW ENGLAND ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ FINAL PREFERENCE: BLEND OF 00Z GFS/00Z ECMWF CONFIDENCE: AVERAGE INTERACTION/MERGING OF CANADIAN COLD FRONT MOVING THROUGH NEW ENGLAND AND THE SURFACE LOW OFF MID-ATLANTIC COAST WITH TRAILING SURFACE TROUGH LINGERS ACROSS THE NORTHEAST THROUGH SATURDAY BEFORE MOVING OFFSHORE. THE CLUSTERING OF THE LOW REMAINS POOR BUT THE ELONGATION OF THE TROF SEEMS REASONABLE. THE 00Z NAM CONTINUES IT TREND TO ACCELERATE THE SURFACE LOW UP THE NORTHEAST SEABOARD QUICKER ALONG THOUGH THE 00Z UKMET HAS BACKED OFF A BIT. THE 00Z CMC HAS A MORE CONSOLIDATED AND STRONGER SURFACE RESPONSE NOT GIVING IT MUCH SUPPORT EITHER. THE 00Z ECMWF CAME IN A BIT WEAKER AND FURTHER NORTH WITH THE SURFACE LOW MAKING THE 00 GFS THE SOUTHERN OUTLIER... STILL GIVEN THE GOOD AGREEMENT OF THE OVERALL SURFACE TROF A BLEND OF THE 00Z GFS/ECMWF IS STILL PREFERRED BUT AT ONLY AVERAGE CONFIDENCE GIVEN THIS SORT OF SPREAD AT SUCH AS SHORT TIME INTO THE FORECAST PERIOD. SHORTWAVE/LOW MOVING THROUGH THE NORTHERN TIER SUN/TUES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ FINAL PREFERENCE: BLEND OF 00Z GFS/12Z ECMWF ENSEMBLE MEAN CONFIDENCE: AVERAGE EVOLUTION OF THE NORTHERN STREAM SHORTWAVE CONTINUES TO BE IN FAIRLY GOOD AGREEMENT AS IT DEEPENS INTO A LARGER SCALE WAVE OVER THE GREAT LAKES AND EASTERN CANADA BY DAY 3. THIS AGREEMENT IS STRONGEST WITH THE EVOLUTION OF THE SURFACE LOW ON SUNDAY INTO THE WESTERN GREAT LAKES WITH VERY STRONG/TIGHT CLUSTERING OF OPERATIONAL AND ENSEMBLE MEMBERS. SLIGHT DIFFERENCES BEGIN TO SHOW UP ALOFT BY MONDAY AT 00Z...AS THE GFS HAS A MUCH STRONGER WAVE THAT ORIGINATES OUT OF THE EASTERN GULF OF ALASKA AND REMAINS STRONG AND CONSOLIDATED IT DEEPENS THE TROF ACROSS THE GREAT LAKES ON MONDAY NIGHT INTO TUESDAY. STILL THIS DOES NOT APPEAR OUT OF LINE AND REMAINS A VIABLE SOLUTION. THE 00Z ECMWF HAS TRENDED STRONGER WITH THE DEPTH OF TROF AS IT PROGRESSES INTO THE GREAT LAKES AND MIDWEST BY MONDAY LIKELY IN RESPONSE TO PULLING SOME ADDITIONAL ENERGY OUT OF THE SHEARING OUT GREAT BASIN UPPER LOW.... THIS SOLUTION IS SUPPORTED BY THE 00Z CMC. THE ORIENTATION OF THE TROF REMAINS IN PHASE WITH THE ENSEMBLE MEANS AND 00Z UKMET/GFS/NAM...AND DOES NOT REFLECT A SIGNIFICANT DIFFERENCE TO THE EVOLUTION OF THE SURFACE LOW/TRAILING COLD FRONT OVER THE PLAINS. STILL GIVEN THE CHANGE AND THE UNCERTAINTY OF ENERGY BEING INJECTED BY CONVECTION ACROSS THE HIGH PLAINS WITH THE SHEARING OUT OF THE GREAT BASIN TROF... WILL EXCLUDE THIS RUN FROM THE BLEND AS IT WOULD BE DEEPER MEMBER OF THE 12Z ECMWF ENSEMBLE SOLUTIONS. A BLEND OF THE 12Z ECMWF ENSEMBLE MEAN AND 00Z GFS IS PREFERRED AT THIS TIME...WITH AN AVERAGE CONFIDENCE. OF NOTE THE 00Z UKMET CONTINUES THE 12Z TREND OF STRONGER AND FASTER WITH THE NEXT SHORTWAVE MOVING ACROSS WESTERN CANADA BY DAY 3. TROPICAL CYCLONE BLANCA ~~~~~~~~~~~~~~~~~~~~~~~~ FINAL PREFERENCE: BLEND OF 00Z GFS/UKMET/ECMWF CONFIDENCE: SEE NHC ADVISORIES FOR BLANCA A BLEND OF THE 00Z ECMWF...00Z UKMET AND 00Z GFS APPEARS TO BE BEST IN LINE WITH NHC'S SOLUTIONS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... GALLINA