706  
FXUS10 KWNH 100644  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
243 AM EDT SUN MAY 10 2020  
 
VALID MAY 10/0000 UTC THRU MAY 13/1200 UTC  
 
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION INCLUDING LATEST PREFERENCES AND CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..EXITING DEEP LAYER CYCLONE IMPACTING THE NORTHEAST
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE DETAILS OF THE DEEP  
LAYER CYCLONE CURRENTLY IMPACTING THE NORTHEAST, WHICH WILL BE  
LIFTING OFF TO THE NORTHEAST ACROSS THE CANADIAN MARITIMES THROUGH  
TONIGHT AND SUNDAY. A GENERAL MODEL BLEND IS PREFERRED.  
 
...COMPACT SHORTWAVES/SURFACE LOW IMPACTING THE NORTHERN PLAINS  
AND MIDWEST THIS WEEKEND...  
...ENERGY AMPLIFYING FROM THE OH VALLEY TO THE NORTHEAST MON AND  
TUES...  
...SHORTWAVE MOVING ACROSS THE GREAT LAKES AND NORTHEAST TUESDAY  
AND WEDNESDAY...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND THROUGH 00Z WEDNESDAY, FOLLOWED BY  
A NON-UKMET COMPROMISE  
CONFIDENCE: ABOVE AVERAGE  
 
THE GUIDANCE TAKES THE VIGOROUS COMPACT SHORTWAVE AND ASSOCIATED  
SURFACE LOW OVER THE NORTHERN PLAINS SOUTHEASTWARD ACROSS THE  
MIDWEST GOING THROUGH SUNDAY. ON MONDAY THIS LEAD ENERGY AND A  
FAST-MOVING SECONDARY SHORTWAVE IN ITS WAKE WILL CONSOLIDATE AND  
TRANSIT THE OH VALLEY. AS THE ENERGY ROUNDS THE BASE OF THE LARGER  
SCALE TROUGHING THAT WILL BE PERSISTING FROM THE GREAT LAKES  
REGION INTO MUCH OF SOUTH-CENTRAL AND SOUTHEAST CANADA, THIS OH  
VALLEY ENERGY SHOULD AMPLIFY, AND BY TUESDAY ALL OF THE MODELS  
SUPPORT THE IDEA OF A NEGATIVELY TILTING SHORTWAVE AND POSSIBLE  
CLOSED MID-LEVEL LOW CROSSING NEW ENGLAND ALONG WITH AN  
INTENSIFYING SURFACE LOW CENTER.  
 
EARLY TRENDS IN THE 00Z MODELS SUGGEST MODELS ARE MOVING INTO  
BETTER AGREEMENT WITH THEIR HANDLING OF THIS CONSOLIDATING  
SHORTWAVE MOVING FROM THE OHIO VALLEY INTO THE NORTHEAST ON  
MONDAY. THE NAM WHICH HAD SHOWN A MORE AMPLIFIED SHORTWAVE MOVING  
FROM THE OHIO VALLEY INTO THE NORTHEAST LATE TUESDAY, HAS BACKED  
AWAY SOME FROM THAT SOLUTION - MOVING ITS 00Z RUN INTO BETTER  
AGREEMENT WITH THE OVERALL MODEL CONSENSUS. THE GFS HAS ALSO  
TRENDED TOWARD THE CONSENSUS AS WELL. WHILE ITS 12Z RUN WAS  
FASTER THAN MOST MODELS LIFTING THE SHORTWAVE ACROSS THE NORTHEAST  
LATE MONDAY INTO EARLY TUESDAY, THE 00Z GFS IS NOW SLOWER. THIS  
PUTS MOST OF THE DETERMINISTIC GUIDANCE INTO FAIRLY GOOD AGREEMENT  
THROUGH 12Z TUESDAY AS THE LEADING FEATURE MOVES FROM NORTHERN NEW  
ENGLAND INTO THE CANADIAN MARITIMES.  
 
WITH RESPECT TO THE UPSTREAM TROUGH MOVING ACROSS THE GREAT LAKES  
INTO THE NORTHEAST ON TUESDAY, THE MODELS ARE IN OVERALL GOOD  
AGREEMENT UNTIL AROUND 00Z WEDNESDAY. THEN THE UKMET BECOMES A  
SLOWER OUTLIER AS THE SYSTEM MOVES ACROSS THE NORTHEAST.  
   
..SHORTWAVE ENERGY CROSSING THE SOUTHWEST ON SUNDAY
 
   
..ENERGY SHEARING ACROSS THE SOUTHERN PLAINS BY TUE
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: AVERAGE  
 
THE MODELS SHOW A WEAK SHORTWAVE CROSSING THE DESERT SOUTHWEST ON  
SUNDAY. THIS ENERGY IS THEN EXPECTED TO GRADUALLY SHEAR OFF TO THE  
EAST AND REACH THE SOUTHERN PLAINS BY TUESDAY AND THE LOWER  
MISSISSIPPI VALLEY BY EARLY WEDNESDAY. WHILE DIFFERENCES IN THE  
FINER DETAILS PERSIST - WITH LOW PREDICTABILITY REGARDING THE  
TIMING/AMPLIFICATION OF THE EMBEDDED ENERGY MOVING ACROSS THE  
SOUTHERN PLAINS - OVERALL SPREAD WITH RESPECT TO THE LARGER SCALE  
PATTERN IS MODEST.  
 
...UPPER TROUGH/CLOSED LOW LIFTING ALONG THE NORTHWEST COAST  
MON-WED...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: NON-NAM CONSENSUS  
CONFIDENCE: ABOVE AVERAGE  
 
AN UPPER TROUGH AND ASSOCIATED CLOSED LOW WILL BE APPROACHING THE  
WEST COAST BY TUESDAY AS THE LARGER SCALE BLOCKING PATTERN ACROSS  
WESTERN NORTH AMERICA BEGINS TO BREAK DOWN. THE NAM REMAINS THE  
GENERAL OUTLIER HERE - BRINGING AN UPPER LOW OVER WESTERN CANADA  
FARTHER WEST, DRAWING THE LOW OFF OF THE COAST FARTHER EAST THAN  
THE MODEL CONSENSUS. THE LATEST RUNS OF THE GFS, ECMWF, UKMET,  
GEFS AND EC ENSEMBLE MEANS ARE IN GENERALLY GOOD AGREEMENT WITH  
OVERALL PATTERN ACROSS WESTERN CANADA AND THE PACIFIC NORTHWEST  
INTO EARLY WEDNESDAY.  
 
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML  
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
PEREIRA/ORRISON  
 

 
 
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