535  
FXUS10 KWNH 300430  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1230 AM EDT WED OCT 30 2019  
 
VALID OCT 30/0000 UTC THRU NOV 02/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..POWERFUL CLOSED LOW OVER THE CENTRAL ROCKIES WED
 
   
..ENERGY CROSSING THE THE PLAINS/MIDWEST/OH VALLEY THURS
 
   
..COLD FRONT/SURFACE WAVE IMPACTING THE EASTERN U.S
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF  
CONFIDENCE: AVERAGE  
 
VIGOROUS SHORTWAVE ENERGY CURRENTLY DROPPING DOWN THROUGH THE  
INTERMOUNTAIN WEST WILL REACH THE CENTRAL ROCKIES ON WEDNESDAY AND  
FOSTER A VERY STRONG MID-LEVEL CLOSED LOW WHICH WILL CROSS THE  
CENTRAL PLAINS AND PORTIONS OF THE MIDWEST AND OH VALLEY THROUGH  
THURSDAY. AS THE ENERGY CROSSES THE OH VALLEY, IT IS EXPECTED TO  
BECOME NEGATIVELY TILTED AND IS FORECAST TO THEN RAPIDLY LIFT  
NORTHEAST ACROSS THE LOWER GREAT LAKES AND NORTHEAST THROUGH  
FRIDAY. MULTIPLE WAVES OF LOW PRESSURE DEVELOPING ALONG AN  
ATTENDANT COLD FRONT WILL INITIALLY EVOLVE OVER PORTIONS OF THE  
TN/OH VALLEYS BY LATE WEDNESDAY, BUT THESE LOWS WILL CONSOLIDATE  
INTO ONE DOMINANT WAVE OF LOW PRESSURE WHICH WILL DEEPEN OVER THE  
UPPER OH VALLEY ON THURSDAY BEFORE LIFTING UP THROUGH THE LOWER  
GREAT LAKES AND NORTHEAST. A STRONG COLD FRONT TRAILING SOUTH FROM  
THE SURFACE LOW WILL CROSS THE EASTERN U.S. AND REACH THE EAST  
COAST BY LATER THURSDAY NIGHT. THE MODEL GUIDANCE HAS FINALLY COME  
INTO BETTER AGREEMENT, AND IN PARTICULAR WITH THE 00Z GFS FINALLY  
SIDING WITH THE MORE CONSISTENT 12Z ECMWF WITH THIS SYSTEM. THE  
00Z NAM FROM 48 HOURS ONWARD TAKES THE CLOSED LOW NORTH OF THE  
GLOBAL MODEL CONSENSUS, AND ALSO APPEARS TO BE TOO DEEP AS THE  
ENERGY CROSSES THE GREAT LAKES AND ADJACENT AREAS OF SOUTHEAST  
CANADA. THE 12Z UKMET AND 12Z ECMWF ARE RELATIVELY CLOSE TO THE  
GFS/ECMWF CAMP WITH TIMING, BUT APPEAR TO BE OVERALL A LITTLE TOO  
WEAK WITH THEIR MID-LEVEL LOW CENTERS. THERE IS STILL SOME SPREAD  
WITHIN THE GEFS AND ECENS MEMBERS WITH HOW DEEP THE HEIGHT FALLS  
WILL BE, BUT FOR NOW A BLEND OF THE 00Z GFS AND 12Z ECMWF WILL BE  
PREFERRED.  
 
   
..NEXT UPPER TROUGH/FRONT OVER THE PLAINS/MIDWEST BY FRI/SAT
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
ANOTHER STRONG SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL  
QUICKLY DROP SOUTHEAST ACROSS THE PLAINS AND MIDWEST FRIDAY AND  
SATURDAY. MODEL SPREAD IS MINIMAL WITH THIS NEXT SYSTEM, SO A  
GENERAL MODEL BLEND WILL BE PREFERRED.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
ORRISON  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page