MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 242 AM EDT TUE JUN 24 2014 VALID JUN 24/0000 UTC THRU JUN 27/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... ============================================== 00Z MODEL EVALUATION AND PREFERENCES ============================================== NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO SIGNIFICANTLY AFFECT THEIR LARGE SCALE OUTPUT. ============================================== ...AMPLIFYING LARGE SCALE TROUGHING IN THE WEST SPILLING INTO THE NORTHERN PLAINS... PREFERENCE: BLEND OF 00Z GFS/ECMWF/CANADIAN CONFIDENCE: ABOVE AVERAGE A MEDIUM WAVELENGTH TROUGH WILL DIG OVER THE WESTERN U.S...DOWNSTREAM OF A STRONGER CLOSED LOW APPROACHING THE PACIFIC NORTHWEST. MODEL AGREEMENT IS FAIRLY STRONG...ESPECIALLY AMONG THE OPERATIONAL AND ENSEMBLE MEMBERS OF THE GFS AND ECMWF. WITH SUPPORT FROM THE OTHER GLOBAL MODELS AND SOME RUN TO RUN CONTINUITY DEVELOPING...CONFIDENCE IS ABOVE AVERAGE. THE UKMET WAS DEEMED JUST SLIGHTLY FLAT BY DAY 3...AND THE NAM IS CONSIDERED JUST SLIGHTLY TOO FAST AND IS NOT QUITE AS DEEP AT THE BASE OF THE TROUGH OVER THE SOUTHWEST U.S. ...MUCH OF THE CENTRAL AND EASTERN U.S... PREFERENCE: BLEND OF 00Z GFS/ECMWF CONFIDENCE: ABOVE AVERAGE THE GFS AND ECMWF ARE HANDLING SOME SMALL SCALE AND LOW AMPLITUDE WAVES WITH RELATIVE SIMILARITY OVER THE WESTERN GREAT LAKES. THE ECMWF...WHICH HAD BEEN SLIGHTLY FAST ON DAY 3 OVER NEW ENGLAND...TRENDED INTO BETTER AGREEMENT WITH THE GFS MASS FIELDS...WHICH THEMSELVES HAD IMPROVED RELATIVE TO THE 12Z RUN. THIS RAISES CONFIDENCE...BUT THERE ARE STILL SOME MEANINGFUL DIFFERENCES...AS THE GFS CONTINUE TO PRODUCE ITS PRECIPITATION SWATH FARTHER NORTH IN NEW ENGLAND. PLEASE REFER TO THE WPC QPF DISCUSSION FOR DETAILS. MEANWHILE...THE NAM MAY HAVE SOME UTILITY THROUGH DAY 2...BUT APPEARS TOO FLAT ALONG THE COAST BY DAY 3...AND TOO DEEP OVER THE GREAT LAKES. ...GULF COASTAL STATES... PREFERENCE: BLEND OF 00Z OPERATIONAL MODELS CONFIDENCE: ABOVE AVERAGE THROUGH DAY 3 A LOW LEVEL RIDGE WILL REMAIN CENTERED IN THE EASTERN GULF OF MEXICO...WITH A RICH FEED OF MOISTURE CIRCULATING AROUND IT AND KEEPING THE FORECAST WET OVER THE GULF STATES AND FLORIDA. THE MODELS HANDLE THE RIDGE SIMILARLY...AND APPEAR TO HAVE AVOIDED ANY EXCESSIVE CONVECTIVE FEEDBACK DURING THE 00Z CYCLE. THE CANADIAN DRIES OUT ALONG THE WESTERN AND CENTRAL GULF COAST BY DAY 3...WHEREAS CONSENSUS WOULD MAINTAIN SCATTERED TO NUMEROUS DIURNALLY-DRIVEN THUNDERSTORMS THROUGH THAT TIME. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... BURKE