161  
FXUS10 KWNH 110439  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1238 AM EDT SAT APR 11 2020  
 
VALID APR 11/0000 UTC THRU APR 14/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION...WITH PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..CLOSED LOW EXITING THE SOUTHWEST
 
   
..ENERGY EJECTING TOWARD THE LOWER MS VALLEY BY SUNDAY
 
   
..POWERFUL SURFACE LOW OVER THE GREAT LAKES BY MONDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: 00Z GFS/12Z UKMET AND ECENS/GEFS BLEND  
CONFIDENCE: AVERAGE...THROUGH 48 HOURS  
BECOMING BELOW AVERAGE...AFTER 48 HOURS  
 
THE LARGE, SLOW-MOVING CUT-OFF SOUTHERN STREAM LOW OVER SOUTHERN  
CALIFORNIA WILL GRADUALLY MOVE TOWARD SOUTHERN AZ/NM LATER TODAY  
AND THEN OPEN UP INTO A PROGRESSIVE SHORTWAVE ACROSS THE SOUTHERN  
PLAINS BY EARLY SUNDAY. BY LATE SUNDAY, THIS ENERGY WILL BEGIN TO  
TAKE ON A NEGATIVE TILT OVER THE LOWER MS VALLEY AND QUICKLY REACH  
THE OH VALLEY BY EARLY MONDAY. THE ENERGY COUPLED WITH INCREASING  
INFLUENCE FROM A STRONG NORTHERN STREAM TROUGH AMPLIFYING OVER THE  
UPPER MIDWEST SUNDAY AND MONDAY WILL LEAD THE WAY FOR A POWERFUL  
SURFACE CYCLONE TO LIFT OVER LOWER MI ON MONDAY. THE MOST RECENT  
GUIDANCE CONTINUES TO ZERO IN ON A SOLUTION FOR THE DEPTH AND  
TRACK OF THE SURFACE LOW AS IT MOVES FROM THE LOWER MS VALLEY TO  
LOWER MICHIGAN. ENSEMBLE LOW TRACK SPREAD HAS LESSENED IN THE LAST  
24 HOURS AND NOW OUTSIDE OF THE NAM (TOO FAST) AND CMC (TOO FAR  
NORTHWEST), THE DETERMINISTIC GFS/UKMET OFFER FAIRLY REASONABLE  
SOLUTIONS WITH THEIR MASS FIELDS, THOUGH THE 12Z ECMWF WAS LESS  
PREFERRED FOR ITS NORTHWEST JUMP. FOR NOW, WILL SIDE ON THE  
FURTHER SOUTH GFS/UKMET SOLUTION AND ALSO THE ECENS/GEFS. BUT IT'S  
ADMITTEDLY A LOWER CONFIDENCE FORECAST BEYOND 48-60 HOURS AND  
THERE COULD BE A TREND TO THE NORTHWEST LIKE WHAT THE 12Z ECMWF  
SUGGESTS.  
 
   
..AMPLIFYING UPPER TROUGH OVER THE NORTHERN U.S. BY MONDAY
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
THE MODELS BRING AMPLIFYING SHORTWAVE/JET ENERGY SOUTHEASTWARD  
FROM THE SOUTHERN COAST OF AK AND THE ADJACENT YUKON TERRITORY  
DOWN ACROSS SOUTHWEST CANADA AND OUT ACROSS THE NORTHERN ROCKIES  
AND NORTHERN PLAINS BY SUNDAY. BY MONDAY, THIS ENERGY WILL AMPLIFY  
INTO A DEEP LONGWAVE TROUGH OVER THE NORTHERN U.S. THAT WILL  
GRADUALLY PHASE WITH THE AFOREMENTIONED SOUTHERN STREAM ENERGY  
EJECTING ACROSS THE SOUTH AND LIFTING TOWARD THE GREAT LAKES  
REGION. THE MODELS ARE IN GOOD AGREEMENT WITH THE DETAILS OF THE  
LONGWAVE TROUGH EVOLUTION. SO, A GENERAL MODEL BLEND WILL BE  
PREFERRED WITH THIS.  
 
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML  
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
TAYLOR  
 

 
 
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