Prognostic Meteorological Discussion
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000
FXUS10 KWNH 250702
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
301 AM EDT THU MAY 25 2017

VALID MAY 25/0000 UTC THRU MAY 28/1200 UTC

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

00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CLOSED UPPER LOW OVER THE UPPER MIDWEST DIGGING ACROSS THE
MIDDLE/LOWER MS VALLEY LATER TODAY AND TRACKING TOWARD THE EAST
COAST THU...EXITING NEW ENGLAND FRI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE

THE LATEST DETERMINISTIC MODELS REMAIN IN OVERALL GOOD AGREEMENT
WITH THE LARGER SCALE FEATURES ASSOCIATED WITH THIS SYSTEM AS IT
MOVES FROM THE OH VALLEY ON THU TO THE NORTHERN NEW ENGLAND COAST
BY LATE FRI.

CLOSED LOW TRACKING ALONG THE WESTERN US/CANADIAN BORDER WITH
DEVELOPING TRAILING TROUGH ACROSS SNAKE RIVER PLAIN FRI...NORTHERN
ROCKIES SAT AND NORTHERN PLAINS SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY BELOW AVERAGE

THE 00 UTC NAM AND GFS HAVE REMAINED FAIRLY CONSISTENT WITH THEIR
12 UTC RUNS.  THEREFORE SOME DIFFERENCES CONTINUE LATE IN THE
PERIOD ACROSS THE UPPER MIDWEST...WITH THE NCEP MODELS REMAINING
SLOWER AND MORE AMPLIFIED WITH THE UPPER TROUGH THAN THE LATEST
RUNS OF THE ECMWF/UKMET/CANADIAN GLOBAL.  IN ADDITION TO THE
DIFFERENCES ALOFT...THE NCEP MODELS BOTH TRACK A SLIGHTLY DEEPER
SURFACE LOW MORE QUICKLY TO THE NORTHEAST ACROSS THE MID MS VALLEY
INTO THE GREAT LAKES REGION EARLY SUN.  THE 00 UTC UKMET IS SLOWER
AND MORE AMPLIFIED WITH THE UPPER TROUGH THAN ITS PREVIOUS RUN
ACROSS THE UPPER MIDWEST...WHILE THE CANADIAN HAS REMAINED FAIRLY
CONSISTENT.  HOWEVER...NEITHER ARE AS SHARP WITH THE TROUGH AS THE
NCEP MODELS SHOW ACROSS THE EASTERN DAKOTAS AND MN AT THE END OF
THE PERIOD.  THE 12 UTC ECMWF...WHICH HAD BEEN ALONG THE FASTER
AND LESS AMPLIFIED EDGE OF THE GUIDANCE...IS NOW SLOWER AND MORE
AMPLIFIED AS WELL AND IN GENERALLY GOOD AGREEMENT OVERALL WITH THE
UKMET AND CANADIAN GLOBAL...BOTH WITH THE UPPER TROUGH AND THE
TIMING OF THE SUFFACE LOW.  THE 00 UTC GEFS MEAN SUPPORTS ITS
DETERMINISTIC RUN ALOFT...WHILE THE 00 UTC ECMWF IS NOW SLOWER
THAN ITS 12 UTC ENSEMBLE MEAN.  THE 00 UTC NAEFS...LEANS CLOSER TO
THE NCEP SOLUTIONS.  WITH THE 00 UTC GUIDANCE SHOWING SOME
EVIDENCE OF CONVERGENCE TOWARD A COMMON SOLUTION...FORECAST
CONFIDENCE HAS INCREASED...BUT REMAINS SLIGHTLY BELOW AVERAGE
GIVEN THE CONTINUED SPREAD.  TO ADDRESS THESE LINGERING
DIFFERENCES...A GENERAL MODEL BLEND IS RECOMMENDED.

WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML... /ALL LOWER CASE/
WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML... /ALL LOWER CASE/

PEREIRA

$$





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