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000
FXUS10 KWNH 220428
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1227 AM EDT WED MAR 22 2017

VALID MAR 22/0000 UTC THRU MAR 25/1200 UTC

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

...PLEASE NOTE THAT THE NAM WAS UPGRADED TO A NEW VERSION 21/12Z
CYCLE...


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


SYSTEM MOVING INTO THE WEST FRIDAY NIGHT
UPPER LOW CLOSING OFF IN THE BAHAMAS
UPPER TROUGH LEAVING NEW ENGLAND TODAY
SHORTWAVE STREAKING THROUGH SOUTHEAST CANADA
FRONT MOVING INTO THE NORTHEAST SATURDAY MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS.  A
COMPROMISE OF THE AVAILABLE GUIDANCE, SIMILAR TO THE PARALLEL
VERSION OF THE NATIONAL BLEND OF MODELS, IS PREFERRED WITH ABOVE
AVERAGE CONFIDENCE.


DEEP CYCLONE MOVING THROUGH THE SOUTHERN PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: COMPROMISE OF THE AVAILABLE GUIDANCE
CONFIDENCE: AVERAGE

THE 12Z ECMWF/ITS ENSEMBLE MEAN REMAIN NORTHEAST OF THE OTHER
GUIDANCE WITH THIS SYSTEM.  IT APPEARS THIS IS DUE TO A SLIGHTLY
MORE PROGRESSIVE TROUGH/RIDGE COUPLET OUT WEST AND SLIGHTLY MORE
TROUGHING ALOFT NEAR MICHIGAN.  THE RIDGE MOVING OVER THE TOP OF
THE SYSTEM SHOULD SLOW ITS PROGRESSION, AND FOR NOW, THE ECMWF AND
ENSEMBLE MEAN PROGRESSION IN THE WEST SLIGHTLY EXCEEDS THE REST OF
THE GUIDANCE.  PREFER A COMPROMISE OF THE AVAILABLE GUIDANCE --
SIMILAR TO THE PARALLEL VERSION OF THE NATIONAL BLEND OF MODELS --
WHICH IS A SOLUTION WEIGHTED SLOWER THAN THE 12Z ECMWF.
CONFIDENCE IS AVERAGE IN THIS CHOICE.


www.wpc.ncep.noaa.gov/html/model2.shtml...

www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

Roth
$$





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