Prognostic Meteorological Discussion
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000
FXUS10 KWNH 250632
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT SAT OCT 25 2014

VALID OCT 25/0000 UTC THRU OCT 28/1200 UTC

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


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


POST-TROPICAL CYCLONE ANA/
DEEP CYCLONE APPROACHING THE PACIFIC NORTHWEST MON/TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/UKMET/CANADIAN/ECMWF COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM IS MUCH WEAKER ALOFT WITH THIS SYSTEM WHEN COMPARED TO
THE OTHER GUIDANCE.  THERE SHOULD BE ENOUGH SEPARATION BETWEEN
THIS SYSTEM AND OTHER SYSTEMS ACROSS THE NORTHEAST PACIFIC AND
NORTHWEST CANADA FOR THE CYCLONE TO BE CLOSED AT 500 HPA, SO
PREFER A COMPROMISE OF THE GFS/UKMET/ECMWF/CANADIAN GUIDANCE.
THIS IS IN LINE WITH THE LATEST FORECAST FROM CPHC AND THOUGHTS
FROM OPC...SEE CPHC PRODUCTS FOR THE LATEST INFORMATION ON
HURRICANE ANA.


DEEP CYCLONE MOVING THROUGH THE WEST AND PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECMWF
CONFIDENCE: AVERAGE

THE 00Z GFS/00Z UKMET ARE QUICKER THAN THE OTHER GUIDANCE LATE
MONDAY/TUESDAY, WHICH IS MOST NOTICEABLE AT THE 500 AND 700 HPA
LEVELS -- ONE OF THEIR USUAL BIASES.  THE 00Z NAM MOVES THE SYSTEM
ALOFT A TOUCH SLOWER THAN THE OTHER GUIDANCE -- WHICH FITS ITS
USUAL BIASES -- INCLUDING THE 12Z ECMWF AND 18Z GEFS MEANS. THIS
PROGRESSION ISSUE ALOFT IS REFLECTED WITHIN THE NAM`S FRONTAL
PROGRESSION ACROSS THE SOUTHERN PLAINS LATE MONDAY/EARLY TUESDAY.
THE 00Z CANADIAN IS THE MOST SOUTHERLY WITH THE CLOSED CYCLONE --
ONE OF ITS USUAL BIASES.  THE 00Z ECMWF SPLITS THE DIFFERENCE SEEN
IN THE 12Z ECMWF/00Z GEFS ENSEMBLE MEANS.  OVERALL, THE FLOW
PATTERN SHOULD REMAIN PROGRESSIVE WITH DEEP CYCLONES TRACKING NEAR
THE 50TH PARALLEL.


DEEP CYCLONE MOVING ACROSS NEW ENGLAND/ATLANTIC CANADA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: HIGH

THE GUIDANCE IS IN GOOD AGREEMENT WITH THIS SYSTEM.


...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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