123  
FXUS10 KWNH 021652  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1251 PM EDT SAT NOV 02 2019  
 
VALID NOV 02/1200 UTC THRU NOV 06/0000 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
   
..12Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..OVERALL PATTERN ACROSS THE CONUS
 
 
PREFERENCE: GENERAL MODEL BLEND, WEIGHTED LESS TO 12Z GFS/NAM  
AFTER MONDAY MORNING (04.12Z)  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
MODEL AGREEMENT ON THE OVERALL SYNOPTIC PATTERN IS VERY GOOD, WITH  
THE AVAILABLE DETERMINISTIC MODELS GENERALLY WITHIN THE ENVELOPE  
OF ENSEMBLE SPREAD. THE ENSEMBLE SPREAD ITSELF IS RELATIVELY  
SMALL, WITH ECMWF ENSEMBLE 500MB HEIGHT SPREAD NEAR OR BELOW THE  
PREVIOUS 30-DAY AVERAGE ACROSS THE ENTIRE CONUS OVER THE NEXT FEW  
DAYS. THEREFORE, A GENERAL MODEL BLEND IS PREFERRED.  
 
THERE ARE SOME IMPORTANT DETAIL DIFFERENCES, PRIMARILY WITH  
SHORTWAVES MOVING THROUGH THE STRONGER FLOW AT THE BASE OF A BROAD  
TROUGH FROM THE NORTHERN PLAINS, TO THE MIDWEST, TO THE NORTHEAST.  
THIS AFFECTS THE PLACEMENT OF SOME AREAS OF PRECIPITATION --  
INCLUDING ONE SWATH IN THE UPPER MIDWEST ON SUNDAY NIGHT AND  
MONDAY, AND ANOTHER NEAR THE NORTHEAST COAST ON TUESDAY. IN  
GENERAL, THE PLACEMENT OF AREAS OF PRECIPITATION WAS NEAR A MEDIAN  
POSITION OF THE AVAILABLE MODELS, GIVEN A LACK OF IDENTIFIABLE  
BIAS FROM ANY INDIVIDUAL MODELS AND THE VERY MINOR DIFFERENCES IN  
THE MASS FIELDS OVERALL.  
 
BY MONDAY NIGHT AND TUESDAY, LESS WEIGHT WAS PLACED ON THE GFS AND  
NAM. BOTH MODELS BEGIN TO SHOW A TREND TOWARD LOWER HEIGHTS THAN  
THE GLOBAL MODEL CONSENSUS, PARTICULARLY WITH ONE WAVE IN THE  
NORTHEAST, AND ANOTHER IN THE INTERMOUNTAIN WEST. THIS AFFECTS  
PLACEMENT OF PRECIPITATION NEAR THE NORTHEAST COAST ON TUESDAY,  
AND HOW QUICKLY A CLOSED UPPER LEVEL LOW NEAR NORTHERN BAJA  
CALIFORNIA EJECTS EAST.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
LAMERS  
 

 
 
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