Prognostic Meteorological Discussion
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000
FXUS10 KWNH 200632
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT WED AUG 20 2014

VALID AUG 20/0000 UTC THRU AUG 23/1200 UTC

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

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


LOWER 48
~~~~~~~~
PREFERENCE: GFS/ECMWF/UKMET COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM IS STRONG WITH ENERGY MOVING ACROSS THE CENTRAL
US/CANADIAN BORDER FRIDAY (ITS USUAL BIAS) WHILE THE 00Z CANADIAN
IS WEAK. THE 00Z CANADIAN IS MORE PROGRESSIVE THAN THE OTHER
GUIDANCE WITH TROUGHING IN THE SOUTHWEST/CENTRAL ROCKIES ON
FRIDAY.  THE 00Z CANADIAN SHALLOWER WITH A TROUGH/POSSIBLE CLOSED
LOW EXPECTED ACROSS THE NORTHERN GREAT BASIN (EVEN WHEN COMPARED
TO THE 00Z GEFS/12Z ECMWF ENSEMBLE MEAN SOLUTIONS) WHICH LIKELY
LED TO DOWNSTREAM ISSUES.  WITH STRONG RIDGING EXPECTED ACROSS THE
EASTERN PACIFIC, THE DOWNSTREAM TROUGH IN THE WEST SHOULD BE
STRONG, RULING OUT THE CANADIAN FROM CONSIDERATION.  SINCE THE
GFS/ECMWF/UKMET GUIDANCE IS SO AGREEABLE AT 500 HPA, 700 HPA, AND
THEIR SURFACE PRESSURE PATTERNS, PREFER A NON-CANADIAN COMPROMISE
WITH ABOVE 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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