MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1240 AM EDT WED SEP 24 2014 VALID SEP 24/0000 UTC THRU SEP 27/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...CLOSED LOW/TROUGH IMPACTING THE EAST... ...INVERTED TROUGH/SURFACE LOW ALONG THE EAST COAST... PREFERENCE: BLEND OF THE 00Z NAM/12Z GEM AND 12Z ECMWF CONFIDENCE: AVERAGE THE MODELS HAVE CONTINUED TO CONSOLIDATE AROUND A FARTHER WEST SOLN RELATING TO THE CLOSED MID LVL LOW CENTER AND ASSOCD TROUGH AXIS CURRENTLY OVER THE INTERIOR SOUTHEAST. ALL OF THE MODELS DRIVE THIS ENERGY GRADUALLY NWD INTO THE MID-ATLANTIC REGION AROUND THE WRN PERIPHERY OF A STRENGTHENING SUBTROPICAL RIDGE OFF THE EAST COAST. THIS RIDGE OFF THE EAST COAST IS PROGGED TO BUILD WWD SOMEWHAT...AND FOR THIS REASON IT MAKES MORE SENSE THAT A MORE WWD SOLN INVOLVING THE HEIGHT FALLS WOULD EVOLVE. MEANWHILE...AT THE SFC...A WELL-DEFINED INVERTED TROUGH/COASTAL FRONT WILL ESTABLISH ITSELF JUST OFF THE MID-ATLANTIC AND SOUTHEAST COAST. A WEAK SFC LOW IS EXPECTED TO DEVELOP ALONG THIS BNDRY AND POTENTIALLY MOVE INLAND OVER ERN NC AND THE DELMARVA LATE WED AND THURS BEFORE THEN SHIFTING BACK OFFSHORE ON FRI. THE ECMWF HAS BEEN VERY CONSISTENT ALONG WITH THE ECENS MEAN IN INDICATING A SOLN THAT IS FARTHER INLAND. THE GEM...NAM AND SREF MEAN ALL SUPPORT A FARTHER WEST SOLN LIKE THE ECMWF. THE UKMET AND GFS ARE A LITTLE FARTHER EAST AND FOCUS MORE ENERGY RIGHT ALONG OR OFFSHORE THE MID-ATLANTIC COAST THROUGH THE PERIOD. BASED ON STRONG CONTINUITY SEEN ON THE ECMWF AND BETTER GLOBAL MODEL AND ENSEMBLE SUPPORT...A SOLN FARTHER WEST WILL BE FAVORED. ...WEAK CLOSED LOW/TROUGH MOVING INTO THE MIDWEST THROUGH THURS... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: ABOVE AVERAGE A WEAK MID LVL CLOSED AND ASSOCD TROUGH CURRENTLY OVER THE NRN/CNTRL PLAINS WILL MOVE ENEWD INTO THE UPR MIDWEST OVER THE NEXT COUPLE OF DAYS. A PORTION OF THIS ENERGY WILL WEAKEN AND SHEAR OFF TO THE NORTHEAST OVER THE UPR GRT LAKES REGION...BUT A LARGE PORTION WILL BREAK OFF AND ACTUALLY SETTLE SWWD TWD THE MID MS VLY REGION THURS AND FRI IN RESPONSE TO A DEVELOPING RIDGE FARTHER NORTH OVER THE UPR MIDWEST AND SRN ONTARIO. ALL OF THE MODELS ARE IN EXCELLENT AGREEMENT ON THIS SCENARIO WITH THE EXCEPTION BEING THE UKMET WHICH IS FARTHER WEST WITH THE ENERGY BY FRI. A NON-UKMET CONSENSUS WILL BE PREFERRED ATTM. ...MID LEVEL LOW FORECAST TO ORGANIZE OVER TEXAS THROUGH THE WEEK... PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF CONFIDENCE: AVERAGE THERE IS VERY BROAD AGREEMENT WITH ALL OF THE LATEST GUIDANCE WITH A WEAK MID LVL LOW CENTER DEVELOPING OVER TX. THERE ARE SOME DIFFS WITH WHERE THE STRONGER VORTICITY SETS UP WITH THE GFS AND ECMWF FOCUSED A LITTLE FARTHER WEST COMPARED TO UKMET AND ESP THE GEM. THE NAM IS SEEN AS THE WEAKEST SOLN. WILL PREFER A BLEND OF THE GFS AND ECMWF ATTM. ...DEVELOPING SURFACE LOW OVER THE GULF OF MEXICO BY EARLY SAT... PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF CONFIDENCE: AVERAGE THE MODELS ARE COMING AROUND TWD A SOLN THAT INVOLVES A SURFACE LOW DEVELOPING ALONG THE SWRN END OF A FRONT OVER THE CNTRL GULF OF MEXICO BY FRI OR SAT DEPENDING ON THE MODEL. THE UKMET AND NAM ARE THE MOST AGGRESSIVE WITH THIS WAVE DEVELOPMENT...WITH THE GFS/GEM AND ECMWF ALL FLATTER. THE LATEST GEFS MEAN AND ECENS MEAN FAVOR A FLATTER SOLN AT LEAST THROUGH EARLY SAT. WILL FAVOR A BLEND OF THE GFS AND ECMWF ATTM. ...DEEP TROUGH/CLOSED LOW ALONG THE WEST COAST THROUGH SAT... PREFERENCE: 00Z NAM CONFIDENCE: AVERAGE ALL OF THE MODELS INDICATE A DEEP TROUGH AND CLOSED LOW MOVING INTO THE WEST FRI AND SAT. THE UKMET AND GFS ARE FARTHER INLAND BY SAT WITH THEIR HEIGHT FALLS. THE GEM AND ECMWF ARE SLOWER AND FARTHER BACK TO THE WEST. THE NAM SPLITS THE DIFF BETWEEN THE TWO CAMPS. THE LATEST GEFS MEAN AND ECENS MEAN FAVOR A SOLN CLOSE TO THAT OF THE NAM. WILL PREFER THE NAM AS A RESULT. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON