926  
FXUS10 KWNH 101644  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1243 PM EDT TUE SEP 10 2019  
 
VALID SEP 10/1200 UTC THRU SEP 14/0000 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
12Z MODEL EVALUATION WITH INITIAL PREFERENCES AND FORECAST  
CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..OVERALL PATTERN ACROSS THE CONUS
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND, STRONGEST WEIGHTS TO...  
10/00Z ECMWF, 10/00Z GEFS MEAN, 10/12Z GFS  
CONFIDENCE: AVERAGE  
 
---PREVIOUS DISCUSSION---  
MODELS CONTINUE TO SHOW SIGNS OF CONVERGING ON A CONSISTENT  
SOLUTION OVER THE PAST COUPLE MODEL CYCLES, AND ARE NOW IN  
REASONABLY GOOD AGREEMENT ON THE SYNOPTIC PATTERN OVER THE NEXT  
FEW DAYS. THE DETERMINISTIC MODELS AND ENSEMBLE MEMBERS ARE  
TIGHTLY CLUSTERED WITH THEIR MASS FIELD FORECASTS AS A TROUGH  
PUSHES THROUGH THE WEST OVER THE NEXT COUPLE DAYS, WITH SOME MORE  
SPREAD EMERGING...ESPECIALLY BY THURSDAY EVENING (13.00Z).  
 
THE 10/12Z GFS AND 10/12Z NAM SHOW THE MORE SUBSTANTIAL DEPARTURES  
FROM ENSEMBLE MEANS OUT OF THE AVAILABLE DETERMINISTIC MODELS, BUT  
ARE STILL GENERALLY SUPPORTED BY THE FULL ENSEMBLE DISTRIBUTION AS  
REASONABLE POSSIBILITIES. FURTHERMORE, THEIR QPF IS SIMILAR IN  
MANY RESPECTS TO THE ENSEMBLE MEANS AND OTHER GLOBAL MODELS.  
 
THEREFORE, A BROAD MODEL BLEND IS THE PREFERENCE, WITH SLIGHTLY  
LESS WEIGHT ON THE LATEST NAM, AND GREATER WEIGHT ON THE ECMWF AND  
THE ENSEMBLE MEANS, WHICH HAVE BEEN MORE CONSISTENT. WITH THE  
TENDANCY FOR ENSEMBLE MEANS TO BE TOO WEAK, A BLEND WHICH INCLUDES  
AT LEAST SOME GFS WOULD HELP OFFSET THAT TENDANCY.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
BANN  
 

 
 
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