Prognostic Meteorological Discussion
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000
FXUS10 KWNH 281838
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
238 PM EDT MON JUL 28 2014

VALID JUL 28/1200 UTC THRU AUG 01/0000 UTC

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


12Z MODEL EVALUATION WITH PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SOUTHERN PLAINS
~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 12Z NAM IS SLIGHTLY STRONGER ALOFT WITH A SHORTWAVE ROUNDING
THE SOUTHWEST SIDE OF THE UNSEASONABLY DEEP CYCLONE IN SOUTHEAST
CANADA -- ITS USUAL BIAS.  BECAUSE OF THIS, IT LURES ITS SURFACE
LOW OUT OF TEXAS PAST THE ARKLATEX, WHICH ENJOYS THE SUPPORT OF
3-5 00Z GLOBAL ENSEMBLE MEMBERS OUT OF 90.  A NON-NAM COMPROMISE
IS PREFERRED HERE WITH ABOVE AVERAGE CONFIDENCE


NORTHERN CONTINENTAL DIVIDE
~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: BELOW AVERAGE

A SHORTWAVE ROUNDING THE TOP OF THE RIDGE IN THE NORTHERN
CONTINENTAL DIVIDE LATE THURSDAY APPEARS TO BE
CONVECTIVELY-INDUCED BY THUNDERSTORM ACTIVITY ACROSS THE GREAT
BASIN AND/OR THE NORTHERN FRINGE OF TROPICAL STORM HERNAN.  THE
GUIDANCE SHOWS THIS FEATURE, THOUGH DIFFERS AS TO ITS FORWARD
PROGRESSION.  THE 12Z GFS/12Z UKMET ARE QUICKER -- THEIR USUAL
BIAS -- WHILE THE 12Z ECMWF/12Z NAM/12Z CANADIAN SHOW A SLOWER
PROGRESSION.  THE GFS HAS TRENDED WEAKER/SLOWER WITH ENERGY ACROSS
THE NORTHERN GREAT BASIN OVER ITS PAST DAY OF RUNS WHILE THE ECMWF
HAS TRENDED SOMEWHAT QUICKER WITH THE ENERGY, FOCUSING ON A
DIFFERENT SHORTWAVE APPARENTLY SHEARING OUT FROM HERNAN.
CONSIDERING THE RELATIVE WEAKNESS OF THE SHORTWAVE AND ITS
CONVECTIVE ORIGIN, PREFER A GENERAL MODEL COMPROMISE FOR THE TIME
BEING WITH BELOW AVERAGE CONFIDENCE CONSIDERING THEIR DIFFERENCE
OF OPINION.


...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...
...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

ROTH
$$





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