Prognostic Meteorological Discussion
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000
FXUS10 KWNH 010633
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT WED JUL 01 2015

VALID JUL 01/0000 UTC THRU JUL 04/1200 UTC

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

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


DEEP CYCLONE MOVING THROUGH WESTERN CANADA FRI/SAT
FRONT DROPPING INTO MONTANA FRIDAY NIGHT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE SHOWS GOOD AGREEMENT WITH THIS SYSTEM.


UPPER LOW/WEAKNESS ACROSS CENTRAL MEXICO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF/CANADIAN COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 00Z UKMET BECOMES A WEAK OUTLIER WITH THIS SYSTEM WHILE THE
00Z NAM IS THE STRONGEST.  A COMPROMISE OF THE 00Z GFS/00Z
ECMWF/00Z CANADIAN APPEARS BEST HERE, AND IS PREFERRED WITH ABOVE
AVERAGE CONFIDENCE.


SECOND WAVE MOVING FROM KS THROUGH THE MID-SOUTH
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECMWF
CONFIDENCE: AVERAGE

THE 00Z GFS/TO SOME DEGREE THE 21Z SREF MEAN WERE THE MOST
AMPLIFIED ALOFT WITH THIS SYSTEM (SIMILAR TO THE 29/12Z ECMWF RUN)
AND BROUGHT THE LOW FARTHEST TO THE NORTH ALONG THE OH RIVER.
THIS IS A PROBLEM AS A WEAK SHORTWAVE UPSTREAM ACROSS ALBERTA LATE
THURSDAY AND MT/ND LATE FRIDAY COULD PREVENT A MORE AMPLIFIED
SOLUTION ALOFT DOWNSTREAM.  THE 00Z UKMET WAS THE WEAKEST ALOFT
AND THE FARTHEST SOUTH WITH THE SURFACE LOW MOVING IT INTO TN.
THE 00Z ECMWF WAS SIMILAR TO ITS OLD ENSEMBLE MEAN SOLUTION WHICH
IS IN THE MIDDLE OF THE GUIDANCE SPREAD, SO IT IS PREFERRED WITH
AVERAGE CONFIDENCE.


FIRST WEAK WAVE MOVING BY THE VA CAPES FRIDAY MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECMWF/UKMET COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z GFS WAS TOO WEAK WITH ITS PARENT SHORTWAVE, WHICH LED TO A
WEAKER AND MORE DEPRESSED SURFACE SOLUTION.  THE 00Z CANADIAN
LOOKS LIKE THE GFS AT THE SURFACE DESPITE ITS REASONABLE SOLUTION
ALOFT.  A COMPROMISE OF THE 00Z ECMWF/00Z UKMET IS SUPPORTED BEST
BY THE 12Z GLOBAL ENSEMBLE LOW CLUSTERING AND IS PREFERRED WITH
SLIGHTLY 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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