Prognostic Meteorological Discussion
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000
FXUS10 KWNH 291829
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
228 PM EDT MON JUN 29 2015

VALID JUN 29/1200 UTC THRU JUL 03/0000 UTC

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

FINAL 12Z MODEL EVALUATION WITH PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SHORTWAVE TROUGH/SURFACE LOW MOVING ACROSS THE GREAT LAKES LATE
TUE/EARLY WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~
PREFERENCE: NON-NAM COMPROMISE
CONFIDENCE: ABOVE AVERAGE

BY LATE TUE ACROSS THE UPPER GREAT LAKES...THE NAM APPEARS TO BE
THE OUTLIER HERE...WITH A SLOWER/MORE AMPLIFIED SOLUTION THAT IS
NOT WELL-SUPPORTED BY THE LATEST DETERMINISTIC GUIDANCE AND THE
09Z SREF.  THE ECMWF...WHICH HAD BEEN ONE OF THE FASTER SOLUTIONS
IS NOW SLOWER...FALLING INTO BETTER AGREEMENT WITH THE GFS AND
UKMET.


SHORTWAVE TROUGHS SPILLING OVER THE WESTERN RIDGE INTO THE
NORTHERN PLAINS-UPPER MIDWEST
TO THE OH AND TN VALLEYS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF COMPROMISE
CONFIDENCE: AVERAGE

FROM LATE TUE TO LATE WED...THE NAM APPEARS TO BE A RELATIVE
OUTLIER HERE AS WELL...CARVING OUT LOWER HEIGHTS THAN THE MODEL
CONSENSUS FROM THE LOWER MO TO THE LOWER OH AND TN VALLEYS.
OVERALL THE GFS/ECMWF ARE IN FAIRLY GOOD AGREEMENT THROUGH LATE
WED.  ON THU THE NAM IS ALONE IS DIGGING THE SHORTWAVE THAT SLIDES
OUT OF SOUTHERN ALB/SASK FURTHER TO THE SOUTHWEST INTO THE
NORTHERN/CENTRAL HIGH PLAINS.  IN CONTRAST...BY LATE THU THE ECWMF
IS WELL TO THE EAST ACROSS THE UPPER MIDWEST WITH THIS
SYSTEM...BUT IT IS WELL-SUPPORTED BY ITS ENSEMBLE MEAN...MAKING IT
DIFFICULT TO DISCOUNT COMPLETELY.

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

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

PEREIRA

$$




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