741  
FXUS10 KWNH 030623  
PMDHMD  
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
122 AM EST SUN NOV 03 2019  
 
VALID NOV 03/0000 UTC THRU NOV 06/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
   
..00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE  
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~   
..OVERALL PATTERN ACROSS THE CONUS  
 
PREFERENCE: GENERAL MODEL BLEND  
EXCEPTION: REMOVE 00Z GFS IN PLAINS AFTER 06.00Z  
CONFIDENCE: ABOVE AVERAGE  
 
07Z UPDATE: A SLIGHT SHIFT/TIGHTENING OF THE INVERTED SURFACE TROF  
ACROSS THE CENTRAL PLAINS IN THE 12Z GEFS ALIGNED BETTER WITH THE  
ECMWF/NAM AND ECENS MEAN SUGGESTS THE SLOWER 00Z GFS IS ON THE  
OUTER FRINGE OF CONSENSUS TO REMOVE IT ACROSS THE PLAINS AFTER  
06.00Z. OTHERWISE, THE ECMWF, CMC AND UKMET SHOW SOLID  
CONSISTENCY. THERE IS SOME SMALL TIMING DIFFERENCES ACROSS THE  
NORTHERN PLAINS/BOUNDARY WATERS OF MN BY THE END OF DAY 3, BUT A  
GENERAL BLEND (WITH EXCEPTION OF THE GFS) REMAINS WARRANTED AT  
ABOVE AVERAGE CONFIDENCE.  
 
---PRIOR DISCUSSION---  
MODEL AGREEMENT ON THE OVERALL SYNOPTIC PATTERN REMAINS VERY  
STRONG, INCLUDING THE 00Z GFS/NAM DETERMINISTIC MODELS GENERALLY  
WITHIN A NARROW ENVELOPE OF ENSEMBLE SPREAD. THERE ARE SOME  
IMPORTANT VERY SMALL SCALE DETAIL DIFFERENCES, PRIMARILY WITH  
SHORTWAVES MOVING THROUGH THE STRONGER FLOW AT THE BASE OF A BROAD  
GLOBAL SCALE TROUGH FROM THE NORTHERN PLAINS, GREAT LAKES, INTO  
THE NORTHEAST. THIS AFFECTS THE PLACEMENT OF SOME AREAS OF  
PRECIPITATION -- INCLUDING ONE SWATH IN THE UPPER MIDWEST ON  
SUNDAY NIGHT AND MONDAY, AND ANOTHER NEAR THE NORTHEAST COAST ON  
TUESDAY. IN GENERAL, THE PLACEMENT OF AREAS OF PRECIPITATION WAS  
NEAR A MEDIAN POSITION OF THE AVAILABLE MODELS, GIVEN A LACK OF  
IDENTIFIABLE BIAS FROM ANY INDIVIDUAL MODELS AND THE VERY MINOR  
DIFFERENCES IN THE MASS FIELDS OVERALL. IN THE SOUTHWEST, A  
CLOSED LOW WILL BE DEVELOPING IN THE VICINITY OF THE CALIFORNIA  
BIGHT, SLOWLY DROPPING SOUTH. BY EARLY WED, THE UPSTREAM RIDGE  
BREAKS DOWN A BIT, ALLOWING FOR NORTHERN STREAM ENERGY TO DIP  
SOUTH ENOUGH TO START PULLING THE CLOSED LOW NORTHEASTWARD. THE  
00Z GFS HAS SLOWED THIS PROCESS, HAVING BEEN THE FASTEST EJECTING  
BACK INTO THE STREAM AND NOW MATCHING THE ECMWF, UKMET, CMC AND  
ENSEMBLE SUITE. THE 00Z NAM IS SLOWER AS WELL, BUT IS A BIT  
FASTER LIFTING OUT, BREAKING FROM STRONGER CONSENSUS. HOWEVER,  
THIS IS FAIRLY SMALL. SO OVERALL, A GENERAL MODEL BLEND CAN BE  
SUPPORTED AT ABOVE AVERAGE CONFIDENCE.  
 
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
GALLINA  
 
 
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