095  
FXUS10 KWNH 230437  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1237 AM EDT TUE JUN 23 2020  
 
VALID JUN 23/0000 UTC THRU JUN 26/1200 UTC  
 
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
 
CLOSED LOW OVER ONTARIO/QUEBEC  
SHORTWAVES OVER THE LOWER MS/OH VALLEYS  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: AVERAGE  
 
THE LARGE CLOSED UPPER LOW OVER WESTERN ONTARIO IS EXPECTED TO  
SLOWLY ADVANCED EASTWARD OVER THE NEXT 3 DAYS, SETTLING INTO  
WESTERN QUEBEC BY THE END OF THE FORECAST PERIOD. IN THE SYNOPTIC  
SENSE, ALL THE MODELS SHOW AVERAGE TO ABOVE AVERAGE CONSISTENCY  
AND AGREEMENT FROM THE PAST FEW RUNS. THE MAIN DIFFERENCES LIE ON  
THE PERIPHERY OF THE TROUGHING WHERE MULTIPLE CONVECTIVELY INDUCED  
SHORTWAVES PUSH ACROSS THE CENTRAL PLAINS TO MS RIVER VALLEY AND  
INTO THE OHIO VALLEY. A GENERAL MODEL BLEND SUFFICES FROM A MASS  
FIELD SYNOPTIC SENSE BUT MORE MESOSCALE DRIVEN DIFFERENCES  
INCLUDING QPF CAN BE EXPECTED HOWEVER.  
 
TROUGHS APPROACHING BRITISH COLUMBIA AND PACIFIC NORTHWEST  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: UKMET/GFS/NAM BLEND  
CONFIDENCE: AVERAGE  
 
SHORTWAVE TROUGH ENERGY WILL MOVE THROUGH PACIFIC NORTHWEST INTO  
THE CENTRAL/NORTHERN ROCKIES OVER THE NEXT COUPLE OF DAYS, WITH A  
MORE SIGNIFICANT SHORTWAVE TROUGH APPROACHING THE REGION ON  
WEDNESDAY NIGHT INTO THURSDAY. AS HAS BEEN THE CASE THE LAST  
SEVERAL RUNS, THE ECMWF HAS SHOWN A FLATTER, MORE PROGRESSIVE FLOW  
PATTERN THAT IS OUT OF SYNC WITH THE REST OF THE DETERMINISTIC  
GUIDANCE WHICH ADVERTISES A SLOWER, MORE AMPLIFIED TROUGH THAT  
DIGS OVER THE ROCKIES INTO THE DAY 3 PERIOD. MEANWHILE THE GFS  
REMAINS A SLOWER SOLUTION AND HAS STRONG SUPPORT FROM ITS ENSEMBLE  
MEAN AS WELL. WHILE THE UKMET/NAM OFFER A MIDDLE GROUND SOLUTION,  
THEY DO LEAN TOWARD A SLOWER APPROACH SIMILAR TO THE GFS, LEAVING  
THE ECMWF AS MORE AN OUTLIER AT THIS TIME.  
 
MID-LEVEL ENERGY LINGERING OVER THE LOWER MS VALLEY/TEXAS  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
LINGERING UPPER LEVEL ENERGY THAT IS EXPECTED TO BECOME REMOVED  
FROM THE WESTERLIES WILL SLOWLY MEANDER OVER THE LOWER MS RIVER  
VALLEY AND TEXAS AREAS WHILE TOWARD THE DAY 2/3 TIME FRAME, WEAK  
TROPICAL ENERGY FROM THE WESTERN GULF APPROACHES TX/LA. MUCH OF  
THE MODEL DIFFERENCES WILL LIE IN THE MESOSCALE SECTOR BUT ON A  
SYNOPTIC SCALE A GENERAL MODEL BLEND SUFFICES.  
 
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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