974  
FXUS10 KWNH 030445  
PMDHMD  
 
MODEL DIAGNOSTIC DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1245 AM EDT FRI NOV 03 2017  
 
VALID NOV 03/0000 UTC THRU NOV 06/1200 UTC  
 
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR  
INGEST...  
 
00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
 
   
..UPPER TROUGH IN THE PACIFIC NORTHWEST TODAY
 
DEAMPLIFYING AND  
EJECTING INTO THE NRN PLAINS THIS WEEKEND...  
...ASSOCIATED COLD FRONT EXTENDING FROM THE GREAT LAKES TO THE SRN  
PLAINS BY MON MORNING...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: BLEND OF 12Z ECMWF / 00Z GFS / 12Z CMC  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
THE 12Z UKMET CONTINUES TO BE FASTER THAN THE LATEST DETERMINISTIC  
MODELS WITH THE SHORTWAVE TRACKING THROUGH S-CNTRL CANADA ON  
SATURDAY AND THE UKMET ALSO REMAINS ON THE FASTEST EDGE OF  
AVAILABLE ENSEMBLE GUIDANCE. DESPITE SOME FASTER TRENDS OVERALL IN  
THE ENSEMBLES SINCE YESTERDAY...THE 12Z UKMET STANDS OUT ENOUGH TO  
DISCOUNT IT FROM THE PREFERENCE. THE 00Z NAM IS ON THE STRONGER  
SIDE OF THE MODEL GUIDANCE AND THE 00Z GFS A BIT WEAKER REGARDING  
THE 500 MB REFLECTION OF THIS SYSTEM. HOWEVER...THE BEST ENSEMBLE  
MEAN AGREEMENT FAVORS A BLEND OF THE 00Z GFS WITH THE 12Z ECMWF  
AND 12Z CMC.  
 
...MID-UPPER LEVEL SHORTWAVE AMPLIFYING TOWARD THE PACIFIC  
NORTHWEST SATURDAY INTO SUNDAY...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: NON 12Z CMC BLEND  
CONFIDENCE: SLIGHTLY ABOVE AVERAGE  
 
MODEL AGREEMENT WITH THE MASS FIELDS FOR THIS SYSTEM IS FAIRLY  
GOOD BUT THERE ARE SOME TIMING DIFFERENCES WORTH NOTING BY MONDAY  
ACROSS THE WEST WITH THE 500 MB TROUGH AXIS. THE DETERMINISTIC  
MODELS HAVE BEEN TRENDING FASTER SINCE YESTERDAY BUT THE TREND IN  
THE ENSEMBLES HAS JUST BEEN TO BE A BIT WEAKER OVER THE PAST 4  
12Z/00Z CYCLES. CURRENTLY THE 12Z CMC STANDS OUT THE MOST WITH A  
MORE AMPLIFIED/SLOWER SOLUTION. BLENDING THE REMAINING NON 12Z CMC  
DIFFERENCES SHOULD WORK THROUGH 12Z/06 WITH AN AVERAGE OF THESE  
MODELS NEAR THE MIDDLE OF THE LATEST ENSEMBLE CLUSTERING.  
 
...UPPER LEVEL SHORTWAVE REACHING TX/OK THIS MORNING AND TRACKING  
EASTWARD THROUGH FRIDAY AND AMPLIFYING OVER FLORIDA ON SATURDAY...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: NON 00Z NAM BLEND  
CONFIDENCE: AVERAGE  
 
THERE REMAINS SOME MINOR STRENGTH DIFFERENCES NOTED WITH THE  
MID-LEVEL REFLECTION OF THIS SYSTEM. THE 00Z NAM REMAINS TOWARD  
THE STRONGER SIDE OF THE MODELS IN THE LOW-MID LEVELS. A NON 00Z  
NAM BLEND SHOWS GOOD AGREEMENT AT THIS TIME WHICH IS REFLECTED IN  
THE PREFERENCE.  
 
...SHORTWAVE CLIPPING NRN NEW ENGLAND TODAY WITH ASSOCIATED  
TRAILING COLD FRONT TO THE SOUTHWEST...  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
PREFERENCE: GENERAL MODEL BLEND  
CONFIDENCE: ABOVE AVERAGE  
 
ONLY MINOR TIMING DIFFERENCES ARE IN PLACE WITH THIS SYSTEM SUCH  
THAT A GENERAL MODEL BLEND CAN BE USED..  
 
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WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML  
 
OTTO  
 

 
 
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