Prognostic Meteorological Discussion
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000
FXUS10 KWNH 110704
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
203 AM EST SUN DEC 11 2016

VALID DEC 11/0000 UTC THRU DEC 14/1200 UTC

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

00Z MODEL EVALUATION ALONG WITH FINAL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

LOW AMPLITUDE SHORTWAVE CROSSING THE GREAT LAKES AND NEW ENGLAND
INTO THE EARLY SUNDAY MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE MODELS CONTINUE TO HANDLE THE SYSTEM COMPARABLY.


PROGRESSIVE SHORTWAVE CROSSING THE UPPER MIDWEST TODAY...PASSING
OVER
THE GREAT LAKES EARLY MON WITH ACCOMPANYING SURFACE LOW/FRONT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 11/00Z GFS/ECMWF
CONFIDENCE: AVERAGE

BOTH THE 11/00Z GFS TRENDED TO A SLOWER AND MORE AMPLIFIED SOLN
COMPARED WITH THEIR 12Z RUNS AS A MID LEVEL IMPULSE APPROACHES THE
GREAT LAKES ON MONDAY.  THE IN THIS RESPECT...THE GFS JOINED THE
NAM IN BEING SLOWER AND DEEPER.  EVEN SO...THE ECMWF REMAINED ON
THE WEAK/FLATTER SIDE OF THE ENVELOPE OF SOLNS.  A BLEND OF THE
GFS AND ECMWF SHOULD RESULT IN A GOOD COMPROMISE WHICH ENDS UP
CLOSE TO BOTH THE GEFS MEAN AND ECMWF ENS MEAN.

REGARDING SURFACE LOW DEVELOPMENT NEAR THE COAST OF MAINE ON
MON...THE 00Z GFS IS TOWARD THE NRN AND STRONGER SIDE OF THE
LATEST ENSEMBLE SPREAD...IN PART GIVEN ITS SLOWER/DEEPER IMPULSE
MAKING ITS WAY ACROSS THE GREAT LAKES SOME 12 TO 18 HOURS EARLIER.
A POSITION CLOSER TO THE 11/00Z ECMWF SHOULD BE GIVEN MORE WEIGHT.


CONTINUED ONSHORE FLOW INTO THE WEST COAST FROM SUN-TUE
EXPECTED FRONTAL WAVE APPROACHING THE N-CNTRL CA COAST ON TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 11/00Z GFS/ECMWF BLEND
CONFIDENCE: BELOW AVERAGE

THE 00Z NCEP OPERATIONAL GUIDANCE KEPT IN FAIR AGREEMENT WITH THE
OTHER OPERATIONAL MODELS IN DEVELOPING A TROUGH DOWNSTREAM OF A
HIGH AMPLITUDE RIDGE ON MONDAY.  THERE REMAINS SIGNIFICANT SPREAD
IN THE ENSEMBLES...WHICH LIMITS CONFIDENCE IN ANY ONE SOLN.


LARGE VORTEX SINKING SSEWD THROUGH S-CNTRL CANADA MON/TUE WITH
  ASSOCIATED ARCTIC COLD FRONT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

THE 00Z NCEP MODELS REMAINED IN FAIRLY GOOD AGREEMENT THROUGH
14/12Z WITH ONLY A FEW OUTLIERS NOTED IN THE LATEST ENSEMBLE
GUIDANCE. STAYING CLOSE TO THE CONSENSUS IS THE COURSE OF ACTION
HERE.

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

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

BANN



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