115  
FXUS10 KWNH 231901  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT FRI AUG 23 2019  
 
VALID AUG 23/1200 UTC THRU AUG 27/0000 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
12Z FINAL MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST  
CONFIDENCE  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..OVERALL PATTERN ACROSS THE CONUS
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
EXCEPTION: 12Z UKMET/ECMWF FL AND OFF CAROLINAS DAYS 2/3.  
CONFIDENCE: AVERAGE  
 
STRONG MODEL AGREEMENT WITH THE SYNOPTIC FLOW ACROSS NORTH AMERICA  
BEGINS TO DIVERGE SUNDAY NIGHT DUE TO SHORTWAVE TROUGH INFLUENCES  
ON THE TROUGH MOVING SOUTHEAST AND FROM TRACK/DEVELOPMENT OF  
INDIVIDUAL LOW CENTERS, BOTH OFF THE NORTHEAST AND THE TROPICAL  
CENTER OFF FLORIDA STARTING SATURDAY NIGHT. THE 12Z GFS REMAINS  
SLIGHTLY MORE AMPLIFIED AND PROGRESSIVE WITH THE NORTH-CENTRAL  
CONUS WHICH RESULTS IN DAY 3 QPF FARTHER NORTHEAST (MOST NOTABLY  
OVER MI) THAN 12Z CONSENSUS WITH THE 12Z ECMWF THE FARTHEST SOUTH.  
ALL GUIDANCE SHIFTED FARTHER EAST WITH THE TRAILING LOW OVER THE  
NORTHEAST CONUS SUNDAY TO THE CANADIAN MARITIMES THROUGH MONDAY  
WITH THE 12Z GFS STILL A BIT FARTHER EAST.  
 
ALL 12Z GUIDANCE SLOWED THE SYSTEM MOVING NORTH FROM SOUTHERN FL  
WITH THE 12Z ECMWF AND UKMET STILL PRACTICALLY IN LOCKSTEP WITH A  
FARTHER OUT TO SEA SOLUTION. THEREFORE, THE PREFERENCE WITH THIS  
SYSTEM OFF THE SOUTHEAST COAST REMAINS WITH THE LATEST UKMET/ECMWF.  
 
SOME TIMING DIFFERENCES WITH THE REMNANTS OF TS IVO BEGIN ON DAY 3  
WITH THE 12Z ECMWF THE MOST PROGRESSIVE AS IT MOVES NORTH.  
HOWEVER, LITTLE DIFFERENCE IS NOTED WITH THE MOISTURE ADVECTION  
INTO THE DESERT SW WHICH MAINLY OCCURS THROUGH DAY 2 WHEN GUIDANCE  
IS IN GOOD AGREEMENT.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
JACKSON  
 

 
 
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