Prognostic Meteorological Discussion
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FXUS10 KWNH 271635
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1235 PM EDT MON JUL 27 2015

VALID JUL 27/1200 UTC THRU JUL 31/0000 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

12Z NAM/GFS EVALUATION...INCLUDING PRELIMINARY PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

STRONG UPPER TROUGH CROSSING THE DAKOTAS ON TUE WITH ATTENDANT COLD
  FRONT CROSSING THE MID-MISS VALLEY EARLY WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

NO SIGNIFICANT TIMING/STRENGTH DIFFERENCES WERE SEEN IN THE MODELS
FOR THIS SYSTEM.


LOW-MID LEVEL TROUGH AXIS IMPACTING THE SOUTHEAST/FL PENINSULA
  THROUGH THU
POTENTIAL UPPER TROUGH / CLOSED LOW REDEVELOPMENT IN THE WRN
  ATLANTIC BY MID TO LATE WEEK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z NAM...12Z GFS...00Z ECMWF BLEND
CONFIDENCE: SLIGHTLY BELOW AVERAGE

WHILE CONFIDENCE IS REDUCED GIVEN GREATER THAN AVERAGE ENSEMBLE
SPREAD...THERE IS ENOUGH AGREEMENT AMONG THE ENSEMBLES TO EXCLUDE
THE 00Z UKMET AS A LIKELY SOLUTION OFF OF THE SOUTHEAST COAST BY
THU. THERE IS BETTER SUPPORT FROM THE ENSEMBLE MEANS TOWARD A
GENERAL BLEND OF THE 12Z NAM...12Z GFS AND 00Z ECMWF WHICH SHOW
DECENT AGREEMENT THROUGH THU EVENING. THE 00Z CMC ALSO STANDS
OUTSIDE OF THE BETTER ENSEMBLE CLUSTERING WITH ITS EASTWARD
DISPLACED SURFACE LOW BY THU.

AGAIN...THE NAM/GFS/ECMWF SHOWED REASONABLE AGREEMENT TO EACH
OTHER FROM THE SURFACE TO THE UPPER LEVELS...ALTHOUGH THE GFS IS
WEST OF THE ECMWF/NAM BY THU IN THE WESTERN ATLANTIC REGARDING A
SURFACE LOW. THEREFORE...A BLEND OF THE GFS WITH THE NAM/ECMWF
FITS THE MODE OF THE PAST SEVERAL RUNS OF THE DETERMINISTIC MODELS.


...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...

...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

OTTO

$$




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