561  
FXUS10 KWNH 080522  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1222 AM EST FRI NOV 08 2019  
 
VALID NOV 08/0000 UTC THRU NOV 11/1200 UTC  
 
..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
...00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES AND  
CONFIDENCE...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
   
..SHORTWAVES CUTTING INTO THE PACIFIC NORTHWEST RIDGE
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: 00Z NAM, 00Z GFS, 12Z ECMWF BLEND WITH INCREASING  
WEIGHT ON ECMWF THROUGH 12Z/11  
CONFIDENCE: SLIGHTLY BELOW AVERAGE  
 
THE LATEST GUIDANCE CONTINUES TO SHOW DIFFERENCES ON THE TEMPORARY  
BREAKDOWN OF AN ANOMALOUS EASTERN PACIFIC RIDGE LATE TODAY INTO  
SATURDAY. TRENDS SHOW CONVERGENCE IN SOLUTIONS COMPARED TO  
YESTERDAY WITH DIFFERENCES WITH SHORTWAVE INTENSITY THROUGH  
SATURDAY MORNING OFF OF THE NORTHWEST COASTLINE. THE 12Z UKMET  
LOOKS TO BE THE MOST AGGRESSIVE WITH A FAVORED MODEL BLEND  
REPRESENTED BY A 12Z ECMWF/00Z NAM/00Z GFS BLEND.  
 
ATTENTION THEN TURNS DOWNSTREAM ACROSS THE NORTH-CENTRAL CONUS AS  
TROUGHING ADVANCING SOUTH FROM CENTRAL CANADA REACHES THE NORTHERN  
TIER ON SUNDAY. THE 00Z GFS HAS TRENDED TOWARD THE REMAINING MODEL  
CONSENSUS COMPARED TO YESTERDAY BUT CONTINUES TO LIE ON THE  
SOUTHERN EDGE OF THE ENSEMBLE SPREAD REGARDING 500 MB HEIGHT  
AMPLIFICATION INTO THE NORTH-CENTRAL CONUS ON SUNDAY INTO MONDAY.  
TIMING DIFFERENCES WITH A RELATED COLD FRONT THROUGH THE GREAT  
PLAINS SHOW THE 00Z GFS AS THE FASTEST WHILE THE 12Z UKMET MAKES  
UP THE OTHER END OF THE SPECTRUM WITH A SLOWER PROGRESSION. A  
COMBINATION OF THE 12Z ECMWF/00Z NAM APPEARS TO BE A FAVORABLE  
BLEND EARLY ON BUT THE 00Z NAM BEGINS TO LAG IN TIMING WITH  
ELEMENTS OF THE GFS LOOKING MORE REASONABLE WHEN COMPARED TO THE  
NAM. THE 12Z ECMWF IS A PREFERRED MIDDLE GROUND BY MONDAY MORNING  
(12Z/11) BUT PIECES OF THE 00Z NAM AND 00Z GFS ARE USABLE  
ELSEWHERE ACROSS THE PLAINS AND MIDWEST ON SUNDAY.  
   
..REMAINDER OF OVERALL PATTERN ACROSS THE CONUS
 
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
A RIDGE-TROUGH PATTERN FROM WEST TO EAST STARTS OFF THE SHORT  
RANGE PERIOD. THERE IS FLATTENING OF THE FLOW INTO SATURDAY  
EVENING WITH A FAST UPPER LEVEL FLOW SETTING UP FROM THE PACIFIC  
NORTHWEST INTO THE MID-ATLANTIC REGION. AMPLIFICATION REAPPEARS BY  
MONDAY MORNING WITH STRONG RIDGING ALONG THE WEST COAST AND  
DOWNSTREAM TROUGHING INTO THE NORTH-CENTRAL CONUS. A CLOSED LOW  
WEST OF SOUTHERN CALIFORNIA IS FORECAST TO NEAR THE BAJA PENINSULA  
THROUGH MONDAY MORNING.  
 
REGARDING THE CLOSED LOW OFF OF THE BAJA PENINSULA AND AN EXITING  
COLD FRONT FROM THE EAST LATER TODAY, THE MODELS ARE IN FAIR  
AGREEMENT WITH A GENERAL MODEL BLEND RECOMMENDED.  
 
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML  
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
OTTO  
 

 
 
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