352  
FXUS10 KWNH 110444  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1243 AM EDT FRI OCT 11 2019  
 
VALID OCT 11/0000 UTC THRU OCT 14/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z INITIAL MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..DEEP CLOSED LOW NEAR THE 40N/70W BENCHMARK  
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
THE NOR'EASTER SITUATED ABOUT 100 MILES SOUTHEAST OF THE 40N/70W  
BENCHMARK HAS GENERALLY LEVELED OFF IN INTENSITY AND IS EXPECTED  
TO REMAIN NEARLY STATIONARY THROUGH MOST OF FRIDAY BEFORE TRACKING  
TOWARDS THE EAST-NORTHWEST AND GRADUALLY WEAKENS AND BECOMES AN  
OPEN WAVE. THIS STORM IS CURRENTLY BLOCKED BY A RIDGE AXIS OVER  
EASTERN CANADA AND PART OF A REX BLOCK PATTERN. BY SATURDAY  
MORNING, THE RIDGE MOVES OUT OF THE WAY AND THE BROAD CIRCULATION  
AROUND THE BIG CENTRAL U.S. LOW BEGINS TO PROPEL THE OCEANIC STORM  
EASTWARD. THERE ARE ONLY MINOR DIFFERENCES IN TIMING OF THE  
EASTWARD TRACK, WITH THE GFS AND GEFS MEAN SLIGHTLY FASTER AND THE  
CMC SLIGHTLY SLOWER. HOWEVER, THEY ARE CLOSE ENOUGH TO MERIT A  
GENERAL MODEL BLEND.  
 
   
..DEEP PLAINS/UPPER MIDWEST CYCLONE  
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
AN IMPRESSIVE UPPER LEVEL TROUGH AND CLOSED LOW OVER THE  
NORTH-CENTRAL U.S. IS SUPPORTING A RAPIDLY DEVELOPING SURFACE LOW  
THAT WILL TRACK ACROSS NORTHERN MINNESOTA TO SOUTHWESTERN ONTARIO  
BY FRIDAY NIGHT, BEFORE MAKING A SLOW CYCLONIC LOOP AND THEN  
EVENTUALLY LIFTING TOWARDS THE NORTHEAST WHILE WEAKENING. THIS  
WILL BE ACCOMPANIED BY A PRONOUNCED COLD FRONT CROSSING THE  
MIDWEST AND EXTENDING SOUTHWARD TO THE GULF COAST, ALONG WITH  
POTENTIALLY RECORD SNOWFALL FOR PARTS OF THE DAKOTAS AND  
NORTHWESTERN MINNESOTA. THE MODELS REMAIN IN VERY GOOD AGREEMENT  
WITH THIS LARGE SCALE STORM SYSTEM THROUGH THE FORECAST PERIOD  
WITH ONLY MINOR DIFFERENCES IN TIMING AND PLACEMENT.  
 
   
..WESTERN U.S.  
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GFS/ECMWF COMPROMISE  
CONFIDENCE: ABOVE AVERAGE  
 
THE NEXT FEATURE OF INTEREST TO AFFECT THE WESTERN U.S. WILL BE A  
PROGRESSIVE UPPER LEVEL TROUGH THAT SHOULD REACH THE WEST COAST BY  
12Z SUNDAY, WITH A FRONTAL BOUNDARY REACHING THE NORTHERN ROCKIES  
BY MONDAY MORNING. THE NAM APPEARS MORE AMPLIFIED THAN THE OTHER  
GUIDANCE, WHILST THE CMC FLATTER AND TOO PROGRESSIVE. BOTH THE  
ECMWF AND GFS APPEAR TO FIT THE PATTERN WELL AND A BLEND OF THESE  
TWO MODELS SHOULD WORK WELL AS A STARTING POINT.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
ORRISON  
 
 
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