201  
FXUS10 KWNH 230639  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
238 AM EDT SAT JUN 23 2018  
 
VALID JUN 23/0000 UTC THRU JUN 26/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION...INCLUDING PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
 
   
..UPPER LOW CROSSING THE OH VALLEY
 
   
..DEAMPLIFYING OVER THE NORTHEAST
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
THE MODELS ARE IN VERY GOOD MASS FIELD AGREEMENT WITH THIS SYSTEM.  
 
   
..UPPER TROUGH CROSSING THE PLAINS/MIDWEST THROUGH SATURDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
THE MODELS ARE IN VERY GOOD MASS FIELD AGREEMENT WITH THIS SYSTEM.  
 
   
..UPPER TROUGH CURRENTLY MOVING INTO THE NORTHWEST
 
   
..AMPLIFYING INTO A CLOSED LOW OVER THE INTERMOUNTAIN WEST
 
   
..EJECTING OUT ACROSS THE PLAINS/MIDWEST MONDAY/TUESDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: BLEND OF THE 00Z GFS AND 00Z ECMWF  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
AN UPPER LEVEL TROUGH ARRIVING ACROSS THE NORTHWEST WILL AMPLIFY  
INTO A CLOSED LOW ON SATURDAY AND DROP DROP DOWN ACROSS THE  
INTERMOUNTAIN WEST THROUGH SUNDAY. ON MONDAY AND TUESDAY, THE  
SYSTEM WILL PROGRESSIVELY EJECT OUT ACROSS THE CENTRAL/NORTHERN  
PLAINS AND THE UPPER MIDWEST. THE GUIDANCE OVERALL IS IN PRETTY  
GOOD AGREEMENT WITH SOME MODEST TIMING DIFFERENCES, ALTHOUGH THE  
00Z UKMET APPEARS TO BE A LITTLE TOO WEAK WITH ITS ENERGY AS IT  
ARRIVES ACROSS THE PLAINS AND UPPER MIDWEST. THE 00Z GFS AND 00Z  
ECMWF CLUSTER TOGETHER THE BEST, AND ESPECIALLY WITH THE DETAILS  
OF SURFACE LOW PRESSURE EAST OF THE ROCKIES, AND SO A BLEND OF  
THESE SOLUTIONS WILL BE PREFERRED.  
 
   
..UPPER LEVEL TROUGH AFFECTING THE NORTHEAST BY MONDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: BLEND OF THE 00Z UKMET AND 00Z ECMWF  
CONFIDENCE: AVERAGE  
 
AN UPPER TROUGH WILL AMPLIFY ACROSS THE NORTHEAST BY MONDAY AND  
THEN EVOLVE INTO A CLOSED LOW NEAR NOVA SCOTIA THROUGH TUESDAY.  
THE NON-NCEP MODELS LED BY THE ECMWF, CMC AND UKMET SOLUTIONS ALL  
SLOWED DOWN A BIT WITH THIS CYCLE AND ARE CLOSER TO THE NAM AND  
GFS WITH RESPECT TO TIMING. HOWEVER, THERE ARE SOME NOTABLE  
DIFFERENCES WITH RESPECT TO THE DEPTH OF THE CLOSED LOW ALONG WITH  
THEIR SURFACE REFLECTIONS SOUTHEAST OF NOVA SCOTIA BY THE END OF  
THE PERIOD. THE GFS IS THE WEAKEST SOLUTION AT THIS POINT,  
FOLLOWED BY THE CMC. THE NAM, UKMET AND ECMWF ALL ARE A BIT  
STRONGER. THE NAM THOUGH DOES TEND TO BE JUST A LITTLE SLOWER THAN  
THE MODEL CONSENSUS. MEANWHILE, THE CMC IS SEEN AS BEING A LITTLE  
MORE PROGRESSIVE AND ESPECIALLY WITH ITS SURFACE WAVE. BASED ON  
THE LATEST TRENDS AND CLUSTERING, A SOLUTION TOWARD A BLEND OF THE  
UKMET AND ECMWF WILL BE PREFERRED AS THE GFS APPEARS TOO WEAK.  
 
   
..UPPER TROUGH CROSSING THE NORTHWEST MONDAY/TUESDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
AN UPPER TROUGH WILL CROSS THE NORTHWEST ON MONDAY AND TUESDAY.  
THE GUIDANCE OVERALL IS IN GOOD AGREEMENT WITH THEIR MASS FIELDS,  
WITH ONLY VERY MODEST TIMING/DEPTH DIFFERENCES, SO A GENERAL MODEL  
BLEND WILL BE PREFERRED.  
 
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML  
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
ORRISON  
 

 
 
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