MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 249 PM EDT WED JUN 08 2016 VALID JUN 08/1200 UTC THRU JUN 12/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION INCLUDING MODEL PREFERENCE AND FORECAST CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ UPPER LOW/TROUGH OVER SOUTHEASTERN CANADA AND THE NORTHEASTERN U.S REINFORCING SHORTWAVES DROPPING ACROSS UPPER MIDWEST TO THE NORTHEAST/MID ATL WED-FRI ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: OPERATIONAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE MODELS CONTINUE TO TIGHTEN IN AGREEMENT AS THE FINER DETAILS IN PRECISE TIMING MANIFEST WITH THE ONLY REMAINING SPREAD EXISTS WITH THE LAST SHORTWAVE AT ABOUT 54-60HRS MOVING THROUGH NEW ENGLAND. THE 12Z IS A BIT SLOWER AND LESS CONSOLIDATED IN COMPARISON TO THE SUITE OVERALL...ATYPICAL OF ITS BIAS AND THE 00Z UKMET IS A BIT DEEPER IN COMPARISON AT 5H. STILL THIS IS QUITE MINOR WITH RESPECT TO THE LARGER SCALE FEATURES TO SUPPORT AN OPERATIONAL MODEL BLEND AT ABOVE AVERAGE CONFIDENCE. WEAK UPPER LOW FROM THE GREAT BASIN INTO THE CENTRAL ROCKIES/HIGH PLAINS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: OPERATIONAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE MODELS REMAIN IN GENERALLY GOOD AGREEMENT WITH THIS FEATURE AS IT EVENTUALLY FADES INTO THE DEVELOPING RIDGE NEAR THE OK/TX PANHANDLES BY SAT TO SUPPORT AN OPERATIONAL MODEL BLEND AT ABOVE AVERAGE CONFIDENCE. SHORTWAVE AND SURFACE WAVE TRACKING ACROSS CANADIAN PRAIRIES CLIPPING NORTHERN TIER OF US THROUGH FRIDAY AND GREAT LAKES BY SAT EVENING. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-CMC BLEND CONFIDENCE: AVERAGE THE 12Z GFS HAS TRENDED MUCH CLOSER TOWARD THE AVERAGE OVERALL AS IT NO LONGER HANGS UP THE SHORTWAVE ACROSS ALBERTA...THOUGH IT ALSO REMAINS ON THE SOUTHERN SIDE OF THE BEST CLUSTERING THROUGH ITS TRANSLATION ACROSS CENTRAL CANADA...THOUGH TIMING/PLACEMENT MATCHES BETTER ACROSS THE NORTHERN TIER OF THE U.S. BY SAT INTERACTION WITH THE ARCTIC STREAM INCREASES SPREAD OVERALL...THOUGH THE 12Z GFS STARTS TO MATCH MORE ALIGNED WITH THE 12Z NAM AND 00Z ECMWF...THE THE 00Z UKMET/CMC CARVE OUT A CLOSED STRONG UL FEATURE OVER ONTARIO THOUGH DOES NOT AFFECT THE TIMING/ORIENTATION OF THE FRONTAL ZONE TOO MUCH ACROSS THE GREAT LAKES BUT LIKELY INDUCES IMPORTANT MESOSCALE INGREDIENTS. SOME INCLUSION OF THE GFS MAY BE WARRANTED BUT WITH BETTER AGREEMENT AND CONSISTENCY/CONTINUITY WILL FAVOR A 12Z NAM AND 00Z ECMWF BLEND AT AVERAGE CONFIDENCE. 19Z UPDATE: LITTLE CHANGE EXCEPT SLIGHT SHIFT SOUTH OVERALL WITH THE 12Z ECMWF KEEPS BEST ALIGNMENT IN TIMING/PLACEMENT WITH THE 12Z NAM...THOUGH DOES ENCAPSULATE A BETTER ALIGNMENT WITH THE 12Z GFS AS WELL...BUILDING SOME CONFIDENCE. BY THE END OF DAY 3...THE UKMET/CMC ARE EARLIER IN CONSOLIDATING AND CLOSING OFF A LOW IN ONTARIO BUT THE UKMET IS CLOSER IN PLACEMENT AS THE CMC LAGS ENOUGH TO BE NOTICEABLE. WILL CONTINUE TO WEIGHT THE 12Z NAM/ECMWF A BIT HIGHER IN A NON-CMC BLEND AT AVERAGE CONFIDENCE. UPPER TROUGH APPROACHING THE WEST BY TUE INTO SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z NAM/GFS/CMC BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE THROUGH 11/00Z... BELOW AVERAGE BY 12/00Z. MODELS AND ENSEMBLES ARE WELL AGREED UPON THROUGH 48HRS TO SUPPORT AN OPERATIONAL MODEL BLEND UP TO THIS POINT. THE 00Z UKMET REMAINS ALONE IN ELONGATING THE UPPER LOW FAVORING THE SHORTWAVE MOVING INTO BRITISH COLOMBIA AND PAC NW FRI. AFTER 84HRS /SAT 12Z/ THE 00Z ENSEMBLE ANALYSIS SHOWS INCREASING SPREAD AS A MULTITUDE OF ECENS MEMBERS BEGIN TO WEAKEN THE TROF AND LIFT IT INTO CANADA WHILE GEFS/CMCE MEMBERS MAINTAIN THE UL ACROSS N CA/OR MUCH SLOWER TO FILL. THE 12Z GFS/NAM AND 00Z CMC ARE MORE IN LINE WITH THIS SLOWER TRANSITION AS ALL SEEM TO ROTATE SOME INTERNAL CORE ENERGY AROUND THE CENTER TO REINFORCE THE BASE WHILE THE ECMWF WAS A BIT MORE DISPLACED AND SLOWER TO DO SO ALLOWING FOR THIS EARLIER SHIFT NE. BY THE END OF THE FORECAST PERIOD THE DISPLACEMENT IS NOT PARTICULARLY DRAMATIC BUT RAPIDLY CHANGES THEREAFTER FOR DAY 4...PLEASE SEE WPC PMDEPD FOR ADDITIONAL INFORMATION. AS SUCH WILL CONTINUE TO FAVOR A NON-UKMET BLEND WITH HIGH CONFIDENCE THROUGH 72HRS REDUCING THEREAFTER TO AVERAGE OR SLIGHTLY BELOW AVERAGE BY 12/00Z. 19Z UPDATE: THE 12Z ECMWF HAS TRENDED FASTER TO MATCH THE UKMET IN LIFTING THE NORTHERN CLOSED LOW INTO BC/ALBERTA BY SAT EVENING...FOLLOWING MANY 00Z ECENS MEMBERS AND CREATING A DISTINCT SPLIT IN MODEL SOLUTIONS AND REDUCING CONFIDENCE OVERALL. THE 12Z CMC IS MORE ELONGATED OVERALL PERHAPS TRENDING A BIT FASTER BUT CURRENTLY RESIDES ON THE FASTER SIDE OF THE SLOWER CAMP. CONTINUITY FAVORS THE SLOWER SOLUTIONS AND GIVEN THE AMPLIFYING RIDGE ACROSS THE CENTRAL U.S...A 12Z NAM/GFS/CMC BLEND BUT CONFIDENCE IS BELOW AVERAGE AFTER 11/00Z GIVEN THE INCREASING SPREAD. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... GALLINA