164  
FXUS10 KWNH 310413  
PMDHMD  
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1212 AM EDT THU OCT 31 2019  
 
VALID OCT 31/0000 UTC THRU NOV 03/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
 
CENTRAL TO EASTERN U.S. STORM THROUGH FRIDAY  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: 12Z GFS AND 00Z UKMET/ECMWF BLEND  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
THE ENVIRONMENTAL PIECES ARE COMING TOGETHER TOWARD THE FAIRLY  
RAPID DEVELOPMENT OF A STRONG SURFACE CYCLONE IN THE OHIO VALLEY  
SLIDING INTO THE ST. LAWRENCE VALLEY TOWARD FRI WITH A STRONG,  
PROGRESSIVE COLD FRONT PRESSING ACROSS THE EASTERN US. THE  
OVERALL GUIDANCE, WHILE THERE ARE SOME SMALL INTERNAL DIFFERENCES  
PARTICULARLY AFTER 36HRS (CMC IS NORTH, AND THE 12Z NAM IS  
SLOWER), THE AGREEMENT IN THE 12Z GFS AND 00Z ECMWF/UKMET WITH  
PRIOR RUNS PROVIDES ABOVE AVERAGE CONFIDENCE IN A GFS/ECMWF AND  
UKMET BLEND.  
 
NEXT UPPER SHORTWAVE, PRESS OF COLD AIR BEHIND FRONT OVER THE  
PLAINS/MIDWEST BY THIS WEEKEND  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: 12Z GFS AND 00Z ECWMF/CMC BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
A NORTHWEST FLOW REGIME SETS UP ACROSS CANADA, ALLOWING FOR  
ANOTHER SHOT OF COLD AIR TO PRESS INTO THE NORTHERN  
PLAINS/BOUNDARY WATERS REGION, SUPPORTING A SURFACE WAVE AND  
FRONTAL BOUNDARY CLIPPING THE GREAT LAKES BY LATE SAT INTO SUNDAY.  
THE 12Z NAM, LIKELY BEING A BIT COLDER WITH ITS KNOWN BIAS, DIGS  
A BIT FURTHER SOUTH AND IS A BIT STRONGER/DEEPER SOUTH WITH THE  
TROF THROUGH THE OHIO AND TENNESSEE VALLEY BY SUNDAY. SIMILARLY  
THE UKMET IS DEEP IN THE UPPER TN VALLEY/S APPALACHIANS, THOUGH  
THIS IS BETTER MASS AGREEMENT WITH THE GFS/ECMWF/CMC THAN THE NAM;  
THIS IS A BIT OUTSIDE OF THE ENSEMBLE SUITE BUT COULD POTENTIALLY  
BE ADDED AT LOWER WEIGHTING IN A BLEND, IF SO DESIRED. HOWEVER,  
WILL FAVOR A 12Z GFS AND 00Z CMC/ECMWF BLEND AT ABOVE AVERAGE  
CONFIDENCE.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
GALLINA  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page