Prognostic Meteorological Discussion
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991
FXUS10 KWNH 050630
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
229 AM EDT THU MAY 05 2016

VALID MAY 05/0000 UTC THRU MAY 08/1200 UTC

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

00Z MODEL EVALUATION INCLUDING PREFERENCES/CONFIDENCE INTERVALS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SYSTEM MOVING BY THE NORTHWEST SATURDAY NIGHT
FRONT CROSSING THE GREAT LAKES SATURDAY MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
THE GUIDANCE SHOWS VERY GOOD AGREEMENT WITH THESE SYSTEMS, SO WE
PREFER A GENERAL MODEL COMPROMISE TO DEAL WITH ANY LINGERING
DETAIL ISSUES WITH ABOVE AVERAGE CONFIDENCE.


SYSTEM MOVING INTO THE SOUTHWEST/GREAT BASIN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM IS SLOW/SOUTHWEST WITH THIS SYSTEM BY SUNDAY MORNING
-- ITS TYPICAL BIAS AT THIS TIME RANGE.  THE OTHER GUIDANCE SHOWS
VERY GOOD AGREEMENT, SO PREFER A COMPROMISE OF THE 00Z
CANADIAN/00Z UKMET/00Z ECMWF/00Z GFS WITH ABOVE AVERAGE CONFIDENCE.


LOW MOVING BY NEW ENGLAND THURSDAY EVENING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECMWF/UKMET COMPROMISE
CONFIDENCE: BELOW AVERAGE

THE 12Z GLOBAL ENSEMBLE GUIDANCE SHOW MUCH MORE DISPERSION THAN
USUAL WITH THIS SYSTEM, THOUGH THE 00Z DETERMINISTIC GUIDANCE HAS
CONVERGED.  OVERALL, THE 00Z UKMET/00Z ECMWF SPLITS THE DIFFERENCE
SEEN IN THE GUIDANCE, AND ARE PREFERRED WITH AVERAGE CONFIDENCE.


LOW NEAR THE MID-ATLANTIC COAST FRIDAY/SATURDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/CANADIAN COMPROMISE
CONFIDENCE: AVERAGE

THE DETERMINISTIC/12Z GLOBAL ENSEMBLE GUIDANCE SHOWS WIDER THAN
NORMAL SPREAD WITH THIS SYSTEM AS WELL, THOUGH NOT QUITE AS WIDE
AS THE NEW ENGLAND SYSTEM.  OVERALL, THE 00Z GFS/00Z CANADIAN BEST
FITS THE MIDDLE OF THE ENSEMBLE LOW CLUSTERING, SO PREFER A
COMPROMISE OF THOSE PIECES OF GUIDANCE WITH AVERAGE CONFIDENCE.


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

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

ROTH
$$





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