Prognostic Meteorological Discussion
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FXUS10 KWNH 270506
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
105 AM EDT MON JUL 27 2015

VALID JUL 27/0000 UTC THRU JUL 30/1200 UTC

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

00Z MODEL EVALUATION...INCLUDING THE 00Z NAM/GFS AND 26/12Z
UKMET/CMC AND ECMWF

...SHORTWAVE IMPULSE CROSSING THE NORTHERN PLAINS/UPPER MIDWEST...

PREFERENCE: NON-NAM CONSENSUS
CONFIDENCE: ABOVE AVERAGE

A SHORTWAVE IMPULSE CURRENTLY EJECTING EAST ACROSS THE UPPER
MIDWEST WILL ADVANCE DOWNSTREAM AND BEGIN TO SHEAR OUT ACROSS
PORTIONS OF THE GREAT LAKES REGION THROUGH MON. THE 00Z NAM
REMAINED A STRONG OUTLIER SOLN AND WAS DISCOUNTED GIVEN EXCELLENT
AGREEMENT AMONG THE GLOBAL MODELS ON A MORE SHEARED/WEAKER SYSTEM
BY COMPARISON.


...UPPER LOW/TROUGH DIGGING THROUGH THE NORTHWEST...
...ENERGY TRAVERSING THE NORTHERN PLAINS/UPPER MIDWEST...
...CYCLOGENESIS OVER THE NORTHERN HIGH PLAINS...

PREFERENCE: BLEND OF 00Z GFS AND 12Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

AN UPPER LOW AND ASSOCIATED TROUGH WILL DIG SOUTHEAST FROM BRITISH
COLUMBIA/WASHINGTON AND MOVE ACROSS THE NORTHWEST U.S. THROUGH THE
DAY TODAY BEFORE EJECTING EAST OUT ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST TUES AND WED. MEANWHILE...LEE-SIDE CYCLOGENESIS OVER
THE NORTHERN HIGH PLAINS WILL OCCUR BY EARLY MON...WITH THE
GUIDANCE AGREEING ON THE DEVELOPMENT OF LOW PRESSURE OVER
SOUTHEAST MT. THE NEW GFS AND OLD ECMWF CONTINUE TO BE IN GOOD
AGREEMENT IN HANDLING THIS SYSTEM AND CONTINUED TO BE THE FAVORED
MODEL SOLNS.

...MID LEVEL TROUGH IMPACTING THE SOUTHEAST/FL PENINSULA...

PREFERENCE: NON-NAM CONSENSUS
CONFIDENCE: ABOVE AVERAGE

THE MODELS MAINTAIN AN ELONGATED MID LEVEL TROUGH AXIS FROM THE
EASTERN GULF OF MEXICO TO THE SOUTHWEST ATLANTIC BASIN THROUGH THE
PERIOD. THE GLOBAL MODELS ARE CLUSTERED WELL ENOUGH OTHERWISE THAT
A NON-NAM CONSENSUS CAN BE PREFERRED.


...UPPER TROUGH REDEVELOPING OFF THE EAST COAST MON AND TUES...

PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE

THE MODELS STRONGLY FAVOR THE IDEA OF A TROUGH RELOADING ALOFT OFF
THE EAST COAST BY TUES AS ENERGY OVER SOUTHEAST CANADA INCLUDING A
CLOSED LOW DROPS SOUTHEAST AND COUPLES WITH LEFTOVER ENERGY
SHEARING THROUGH THE GREAT LAKES ASSOCIATED WITH THE CURRENT UPPER
MIDWEST SHORTWAVE TROUGH. THE GUIDANCE ALSO FAVORS DEVELOPING LOW
PRESSURE WELL OFF THE EAST COAST. THE 00Z NAM REMAINS AS A
STRONGER OUTLIER WITH THE HEIGHT FALLS AND ALSO DEVELOPING SURFACE
LOW PRESSURE. THE 12Z UKMET APPEARS HOWEVER TO BE A TAD TOO
WEAK...WITH THE 12Z GFS/12Z CMC AND 12Z ECMWF SPLIT THE DIFFERENCE
WITH RESPECT TO THE DEPTH OF THE UPPER TROF.  THE GFS AND ECMWF
HAVE BEEN MORE CONSISTENT AND CLUSTER TOGETHER WELL AND HAVE THE
SUPPORT OF THE LATEST GEFS MEAN AND ECENS MEAN...SO A BLEND OF
THESE SOLUTIONS WILL BE PREFERRED.


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

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

BANN

$$





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