Prognostic Meteorological Discussion
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497
FXUS10 KWNH 260445
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1244 AM EDT TUE JUL 26 2016

VALID JUL 26/0000 UTC THRU JUL 29/1200 UTC

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

00Z MODEL EVALUATION...INCLUDING THE NAM AND GFS


...UPPER LEVEL LOW CROSSING THE NORTHERN GULF OF MEXICO...
...ENERGY MOVING INTO TX TUES/WED...

PREFERENCE: NON-NAM CONSENSUS
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM CONTINUES TO BE A BIT DEEPER AND FURTHER WEST WITH THE
UPPER LOW AS IT REACHES THE TX COAST TUE INTO WED. THE 00Z GFS IS
CLOSER TO THE CONSENSUS...AND IT BETTER SUPPORTED BY THE LATEST
ENSEMBLE MEANS. WILL PREFER A NON-NAM CONSENSUS.


...TROUGH OVER THE GREAT LAKES REACHING NEW ENGLAND ON TUES...

PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE MODELS ARE IN SUFFICIENTLY GOOD ENOUGH AGREEMENT THAT A
GENERAL MODEL COMPROMISE CAN BE PREFERRED AT THIS POINT.


...DEVELOPING MID LEVEL TROUGH OVER THE PLAINS/MIDWEST...
...SURFACE WAVE DEVELOPMENT OVER THE OH VALLEY/MID-ATLANTIC...

PREFERENCE: BLEND OF THE 18Z GEFS MEAN AND 12Z ECENS MEAN
CONFIDENCE: BELOW AVERAGE

THE 00Z NAM AND 00Z GFS BOTH ARE A BIT MORE PROGRESSIVE WITH LEAD
SHORTWAVE ENERGY DIGGING SOUTHEAST ACROSS THE CENTRAL
PLAINS/MIDWEST AND THEN EVENTUALLY INTO THE OH VALLEY THIS PERIOD
WHICH IS EXPECTED TO HELP LEAD THE WAY FOR A LARGER SCALE AND
BROAD MID LEVEL TROUGH TO DEVELOP OVER THE MS VALLEY. ADDITIONAL
SHORTWAVE ENERGY DIGGING IN BEHIND THE LEAD ENERGY WILL HELP TO
SHARPEN UP THE TROUGH AXIS WITH TIME. THE NON-NCEP MODELS WITH THE
12Z UKMET/12Z CMC AND 12Z ECMWF ARE ALL SLOWER WITH THE
EVOLUTION...AND ESPECIALLY THE 12Z ECMWF WHICH IS THE SLOWEST AND
DEEPEST.

THE LEAD ENERGY IS ALSO EXPECTED TO HELP GENERATE A WAVE OF LOW
PRESSURE ALONG A FRONT OVER THE OH VALLEY WHICH WILL AIM FOR THE
MID-ATLANTIC STATES. THE NAM AND GFS ARE MORE PROGRESSIVE WITH
THIS AND SUGGEST A STRONGER IMPACT ON THE MID-ATLANTIC BY THE END
OF THE PERIOD...WITH THE UKMET/CMC AND ESPECIALLY THE ECMWF ALL
SLOWER WITH THEIR WAVES AND KEEPING MOST OF THE IMPACTS CONFINED
TO THE OH VALLEY. THE ECMWF THOUGH IS A SLOW OUTLIER WITH ITS
SURFACE WAVE AND WILL BE DISCOUNTED SINCE EVEN THE ECENS MEAN IS
MORE PROGRESSIVE. THE LATEST GEFS MEAN SUGGESTS A SOLUTION SLOWER
THAN THE NAM/GFS CAMP BUT FASTER THAN THE ECENS MEAN AND CLOSE TO
A CONSENSUS OF THE UKMET AND CMC. CONFIDENCE IS LIMITED...BUT THE
PREFERENCE FOR NOW WILL BE TO GO WITH A CONSENSUS OF THE 18Z GEFS
MEAN AND 12Z ECENS MEAN GIVEN THE SPREAD WITHIN THE DETERMINISTIC
GUIDANCE. THIS MEANS DISCOUNTING THE SLOW ECMWF AND FASTER NAM/GFS.

ORRISON

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

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

$$





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