MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 139 AM EDT TUE MAY 23 2017 VALID MAY 23/0000 UTC THRU MAY 26/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH PRELIMINARY PREFERENCES AND CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...SHORTWAVE ENERGY MOVING INTO THE PLAINS AND MS VALLEY TODAY... ...DEEPENING TROUGH AND CLOSED LOW MOVING TOWARDS THE EAST COAST WED INTO THU... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON NAM BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE OVERALL MODELS HAVE COME INTO ABOVE AVERAGE AGREEMENT WITH THE EVOLUTION OF THIS TROUGH AND CLOSED LOW AS IT PROGRESSES EAST. THE 0Z NAM STILL STANDS OUT A BIT AS A DEEP OUTLIER WITH THE CLOSED LOW BY 12Z THURSDAY. MINOR DIFFERENCES EXIST WITHIN THE OTHER DETERMINISTIC GUIDANCE...BUT NOTHING ELSE STANDS OUT AS A LOWER PROBABILITY OUTCOME. THUS A NON NAM BLEND SHOULD SUFFICE. ...SUBTLE SHORTWAVE FEATURES AND SOUTHERN BRANCH JET MOVING ACROSS THE SOUTHEAST TODAY... ...SURFACE LOWS TRAVERSING THE GULF COAST INTO THE SOUTHEAST... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE WHILE SOME MINOR DIFFERENCES STILL EXIST...MODELS HAVE GENERALLY CONVERGED ON SIMILAR SOLUTIONS WITH THIS ACTIVITY MOVING ACROSS THE SOUTHEAST AND MID ATLANTIC. THUS A GENERAL MODEL BLEND SHOULD WORK FINE. ...UPPER TROUGH MOVING ACROSS THE NORTHWEST THROUGH MID WEEK... ...DEVELOPING LONGWAVE TROUGH OVER THE WEST... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 0Z GFS AND 12Z ECMWF BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE A RATHER STRONG UPPER TROUGH IS EXPECTED TO DIG SOUTHEAST ACROSS THE PACIFIC NORTHWEST TUE/TUE NIGHT FROM THE GULF OF AK. THIS ENERGY WILL ADVANCE INLAND SLOWLY...CROSS THE NORTHERN ROCKIES WED AND MOVE INTO THE WESTERN PORTION OF THE NORTHERN PLAINS THU. ADDITIONAL SHORTWAVE ENERGY IS EXPECTED TO DIVE SOUTH AROUND THE BASE OF THIS TROUGH INTO THE INTERMOUNTAIN WEST BY LATE THURSDAY. MODELS ARE INITIALLY IN VERY GOOD AGREEMENT WITH THIS SYSTEM. HOWEVER THE NAM/UKMET/GEM ALL APPEAR A BIT TOO STRONG AND DEEP WITH THE ADDITIONAL SHORTWAVE ENERGY THAT MOVES AROUND THE BASE OF THE TROUGH THURSDAY NIGHT INTO FRIDAY. THE 0Z GFS AND 12Z ECMWF SEEM TO REPRESENT A MORE LIKELY SOLUTION AT THIS TIME. WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML... /ALL LOWER CASE/ WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML... /ALL LOWER CASE/ CHENARD