Prognostic Meteorological Discussion
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000
FXUS10 KWNH 220356
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1155 PM EDT MON JUL 21 2014

VALID JUL 22/0000 UTC THRU JUL 25/1200 UTC

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

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


...MID LEVEL LOW SLOWLY RETROGRADING OVER THE GULF COAST STATES...

PREFERENCE: NON-NAM CONSENSUS
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE IS IN GOOD AGREEMENT WITH THE DETAILS OF WHAT WILL BE
A RETROGRADING MID LVL LOW OVER THE GULF COAST STATES THE NEXT
COUPLE OF DAYS. THE LOW SHOULD RETROGRADE TO THE LWR RIO GRANDE
VLY BY FRI. THE 00Z NAM IS A LITTLE FASTER THAN THE GLOBAL MODEL
CONSENSUS TO RETROGRADE THE LOW...AND IS ALSO FASTER THAN THE
LATEST GEFS MEAN AND ECENS MEAN. AS A RESULT...WILL FAVOR A
NON-NAM CONSENSUS WITH THIS SYS.


...DEEP UPPER TROUGH/CLOSED LOW OVER THE GULF OF AK DROPPING INTO
THE NORTHWEST...
...SURFACE LOW PRESSURE DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES...

PREFERENCE: NON-UKMET CONSENSUS
CONFIDENCE: ABOVE AVERAGE

OVERALL THE MODELS ARE IN EXCELLENT AGREEMENT ON DROPPING A CLOSED
LOW AND ASSOCD UPR TROUGH DOWN FROM THE GULF OF AK THE NEXT COUPLE
OF DAYS AND SWINGING IT INTO THE PAC NORTHWEST BY LATE WED. ON
THURS...THE ENERGY WILL EJECTING EWD ACROSS SRN CANADA AND THE NRN
HIGH PLAINS. THE ONE MODEL THAT APPEARS AS AN OUTLIER IS THE 12Z
UKMET BY WED AND THURS WHEN IT SUGGESTS A NOTABLY MORE PROGRESSIVE
TROUGH CROSSING THE NORTHWEST AND IMPACTING SOUTHWEST CANADA.
THESE HEIGHT FALLS ARE EXPECTED TO INDUCE LEESIDE CYCLOGENESIS
OVER THE HIGH PLAINS OF ALBERTA AND ALSO ERN MT BY EARLY THURS AND
THERE IS VERY GOOD CLUSTERING WITH SURFACE LOW
PLACEMENT...ALTHOUGH AGAIN THE UKMET WAS SEEN BEING A BIT MORE
PROGRESSIVE. GIVEN THE STRONG MODEL CLUSTERING SEEN
OTHERWISE...WILL PREFER A NON-UKMET CONSENSUS FOR THIS SYS.


...MID LEVEL SHORTWAVE CROSSING THE UPPER MIDWEST AND GREAT LAKES
REGION...
...SURFACE LOW CROSSING THE UPPER MIDWEST AND MOVING INTO
ONTARIO...

PREFERENCE: NON-UKMET CONSENSUS
CONFIDENCE: ABOVE AVERAGE

THE 12Z UKMET CAME IN AGAIN A LITTLE TOO FAR NORTH AND A BIT
FASTER THAN THE GLOBAL MODEL CONSENSUS WITH RESPECT TO THE
EVOLVING SURFACE LOW ACROSS THE REGION. THE UKMET IS ALSO PERHAPS
A TAD TOO WEAK ALOFT WITH THE SHORTWAVE ENERGY. THE REMAINING
MODELS ARE REASONABLY WELL CLUSTERED TOGETHER AND SO A NON-UKMET
CONSENSUS 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...

ORRISON

$$





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