Prognostic Meteorological Discussion
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000
FXUS10 KWNH 051841
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
240 PM EDT SUN JUL 05 2015

VALID JUL 05/1200 UTC THRU JUL 09/0000 UTC

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

12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


UPPER TROUGH MOVING THROUGH CNTRL/ERN CANADA MON/TUE
COLD FRONT CROSSING THE NORTHERN PLAINS/GREAT LAKES/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z NAM...12Z GFS...12Z ECMWF BLEND
CONFIDENCE: AVERAGE

OUTSIDE OF THE 12Z UKMET/CMC...WHICH ARE QUICKER TO BRING THE
FRONT THROUGH THE NORTHEAST TUE NIGHT...AGAINST ENSEMBLE AND
REMAINING DETERMINISTIC SUPPORT...THERE ARE NO SIGNIFICANT MASS
FIELD DIFFERENCES TO SPEAK OF WITH THIS SYSTEM WHICH IMPACT THE
LOWER 48. THE 12Z UKMET/CMC HAVE COME INTO BETTER AGREEMENT WITH
THE LATITUDE OF THE FRONT ACROSS THE PLAINS AND MIDWEST ON WED
COMPARED TO THEIR 00Z RUNS.


UPPER TROUGH CROSSING THE UPPER OHIO VALLEY AND CNTRL APPALACHIANS
  THROUGH TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON 12Z UKMET CONSENSUS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

ENSEMBLE SPAGHETTI 500 MB HEIGHTS AT 588 DM HAVE SHOWED A GENERAL
QUICKENING TREND VALID 00Z/07 WITH THE UPPER TROUGH DEPARTING FROM
THE CNTRL APPALACHIANS. MOST OF THE MODELS SHOW REASONABLE
AGREEMENT HERE...BUT THE 12Z UKMET REMAINS WEAKER AND SLIGHTLY
FASTER THAN THE AGREEABLE AND NOW TIGHTLY CLUSTERED
DETERMINISTIC/ENSEMBLE CONSENSUS.


SHORTWAVE CROSSING THE SOUTHWEST AND SOUTHERN PLAINS MON AND TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z ECMWF / 12Z UKMET BLEND
CONFIDENCE: AVERAGE

A LOW-MID LEVEL SHORTWAVE...WHICH BECOMES BETTER DEFINED ACROSS
THE SRN/CNTRL PLAINS ON TUE AND WED...SHOWS SOME NOTABLE
DIFFERENCES IN THE LATEST GUIDANCE. THE 12Z GFS IS LESS DEFINED
WITH THIS FEATURE AND SHOWS WEAKER LOW PRESSURE IN THE 850-700 MB
LAYER COMPARED TO THE REMAINING MODEL CONSENSUS. THE 12Z CMC IS
STILL DISPLACED NORTHWEST OF THE REMAINING MODEL CONSENSUS WITH
THIS FEATURE. THE 12Z ECMWF AND 12Z UKMET HAVE THE BEST AGREEMENT
TO THE ENSEMBLES HERE..AND FITS THE MIDDLE OF THE LATEST SPREAD
AND TRENDS. THE 12Z NAM IS THE SECOND BEST CHOICE HERE BUT IS NOT
INCLUDED IN THE PREFERENCE AS ITS SLIGHTLY STRONG WHICH TENDS TO
BE A NAM BIAS.


EASTERN PACIFIC UPPER LOW HOVERING WEST OF CALIFORNIA THROUGH WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFERENCE: ABOVE AVERAGE

ALL MODELS TAKE AN UPPER LOW OVER THE EASTERN PACIFIC CURRENTLY
CENTERED NEAR 35N 130W SLOWLY EASTWARD INTO THE MIDDLE OF THE WEEK
WITH REASONABLE AGREEMENT AMONG THE 12Z DETERMINISTIC AND LATEST
ENSEMBLE GUIDANCE.


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

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

OTTO

$$




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