MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 239 PM EDT TUE APR 26 2016 VALID APR 26/1200 UTC THRU APR 30/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM/GFS/UKMET/CMC AND ECMWF ...DEEP CLOSED LOW CENTERED OVER EASTERN QUEBEC... ...REINFORCING COLD FRONTS INTO NEW ENGLAND... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS ARE IN GOOD AGREEMENT WITH THESE FEATURES THROUGH WED...SO WILL PREFER A GENERAL MODEL COMPROMISE. ...SURFACE LOWS/FRONT MOVING THROUGH THE MID-ATLANTIC REGION... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS ARE IN GOOD AGREEMENT WITH THE COLD FRONT TIMING AND SURFACE WAVE EVOLUTION ALONG IT THROUGH TONIGHT. ...DEEP CYCLONE EMERGING INTO THE HIGH PLAINS LATE TODAY... ...CROSSING THE MIDWEST/MID-ATLANTIC THURS AND FRI... PREFERENCE: BLEND OF THE 12Z UKMET/12Z CMC AND 12Z ECMWF CONFIDENCE: AVERAGE THE 12Z ECMWF APPEARS BEST WITH THIS SYSTEM AND HAS THE BEST RUN TO RUN CONTINUITY OF ANY DETERMINISTIC MODEL. THE 12Z UKMET HAS NOW COME INTO BETTER AGREEMENT WITH THE REMAINING GUIDANCE AND IS NOT AS FAR NORTH AS ITS PREVIOUS RUN WITH ITS CLOSED LOW/NEGATIVELY-TILTED TROUGH THAT PIVOTS OUT ACROSS THE CENTRAL PLAINS THROUGH WED. ALL OF THE MODELS SUGGEST THIS ENERGY IS THEN EXPECTED TO BEGIN SHEARING OUT ACROSS THE MIDWEST ON THURS BEFORE THEN DROPPING DOWN ACROSS THE MID-ATLANTIC ON FRI. THE BETTER MODEL CLUSTERING SUGGESTS LEANING TOWARD THE NON-NCEP SOLUTIONS WITH A BLEND OF THE 12Z CMC/12Z UKMET AND 12Z ECMWF WHICH ARE WELL SUPPORTED BY THE 00Z ECENS MEAN. THE 12Z NAM APPEARS TO BE TOO SLOW WITH THE EVOLUTION OF THE SYSTEM. THE 12Z GFS ALSO APPEARS TO POSSIBLY BE TOO SLOW ALTHOUGH IT IS NOT AS SLOW AS THE NAM. WILL LEAN TOWARD THE NON-NCEP CAMP AT THIS TIME. ...SYSTEM APPROACHING THE PACIFIC NORTHWEST LATE TODAY... ...DIGGING INTO THE SOUTHWEST BY THURS... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: SLIGHTLY ABOVE AVERAGE ALL OF THE MODELS DROPPING ADDITIONAL JET ENERGY ACROSS THE PACIFIC NORTHWEST BY LATER TODAY WHICH WILL LEAD TO A NEW CLOSED LOW OVER THE SOUTHWEST BY THURS AND THEN OVER THE CENTRAL ROCKIES ON FRI. THE 12Z UKMET GRADUALLY BECOMES SOMEWHAT FASTER THAN THE MULTI-MODEL CONSENSUS BY THE END OF THE PERIOD AND IS ALSO A TAD STRONGER THAN THE MODEL CONSENSUS. THE ENSEMBLE MEANS FAVOR A SOMEWHAT LESS PROGRESSIVE SOLUTION AND CLOSER TO A NON-UKMET CONSENSUS. ...SHORTWAVE/COLD FRONT NEARING THE PACIFIC NORTHWEST BY FRI... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z NAM APPEARS TOO WEAK AND PROGRESSIVE WITH THE NEXT UPPER TROUGH MOVING INTO THE PACIFIC NORTHWEST BY FRI...WITH THE REMAINING GLOBAL MODELS ALL CLUSTERED AROUND A SOMEWHAT SLOWER AND DEEPER SOLUTION WHICH IS SUPPORTED BY THE LATEST GEFS MEAN AND ECENS MEAN. A NON-NAM CONSENSUS IS PREFERRED. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON