Prognostic Meteorological Discussion
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000
FXUS10 KWNH 300641
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
240 AM EDT WED JUL 30 2014

VALID JUL 30/0000 UTC THRU AUG 02/1200 UTC

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


FINAL 00Z MODEL EVALUATION
~~~~~~~~~~~~~~~~~~~~~~~~~~

LARGE UPPER TROUGH ACROSS THE PLAINS AND EAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: MODEL BLEND OF GFS/ECMWF/MEANS
CONFIDENCE: ABOVE AVERAGE

THE LARGE ANOMALOUS TROUGH OVER THE ERN PORTION OF THE COUNTRY
WILL REMAIN SO THROUGH FRI. THE UPPER VORTEX WILL LOOP NEAR JAMES
BAY BEFORE SHEARING OFF TO THE NORTH AND EAST INTO NRN QUEBEC...
WHILE UPSTREAM DYNAMICS GRADUALLY DIG THROUGH THE UPPER MIDWEST
BEFORE SETTLING OVER THE MID MS VALLEY/WRN OH VALLEY. THE
AMPLIFIED UPPER TROUGH AXIS WILL ACTUALLY RETROGRADE DURING THE
FCST PERIOD FROM NEAR THE EAST COAST TO THE MS RIVER... WHILE THE
ASSOCIATED SURFACE COLD/STATIONARY FRONT WILL FOLLOW SUIT FROM
OVER THE WRN ATLANTIC TO THE ERN SEABOARD. OVERALL THE GUIDANCE IS
IN SOLID AGREEMENT WITH THIS LONG WAVE FEATURE... LITTLE SPREAD
OTHER THAN DETAIL DIFFERENCES AND PERHAPS THE 00Z NAM BEING A
SLIGHT OUTLIER SHIFTING THE TROUGH AXIS/FRONT FARTHER WEST BY SAT
MORNING. WPC WILL RECOMMEND A BLEND OF THE GFS/ECMWF AND ITS MEANS
FOR THE FCST PERIOD.


SOUTHERN PLAINS/LOWER MS VALLEY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE GUIDANCE
CONFIDENCE: ABOVE AVERAGE

A SMALL SCALE STRING OF SHORT WAVE DYNAMICS ASSOCIATED WITH THE
MID-LEVEL LOW OVER NRN UT WILL STREAM INTO THE SRN PLAINS ON WED
BEFORE REACHING THE LOWER MS VALLEY ON THURS. THIS WILL RESULT IN
POTENTIAL HEAVY RAIN IN AN ACTIVE NWRLY FLOW REGIME... AS A
SURFACE WAVE PROPAGATES DOWNSTREAM. HEAVY CONVECTIVE RAINS THIS
EVENING OVER ERN CO WILL EXPAND INTO SWRN KS AND OK/TX PANHANDLES
BEFORE ADVANCING INTO OK/EXTREME SRN KS ON WED. THE SHORT WAVE
DYNAMICS BEGIN TO SHEAR OUT A BIT ON THURS INTO THE SOUTH BUT
HEAVY RAIN WILL STILL THREAT THE ARKLATEX INTO MS. OVERALL THE
GUIDANCE SHOWS RATHER SOLID AGREEMENT ON THE DEPTH AND PROGRESSION
OF THIS DETAILED FEATURE WITH A FEW MINOR DIFFERENCES WITH QPF.
WPC WILL RECOMMEND A BLEND OF THE GUIDANCE ON THE PATTERN AND FOR
MORE ON THE QPF... PLEASE REFER TO THE LATEST QPFPFD.


INTER-MOUNTAIN WEST
~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF BLEND
CONFIDENCE: AVERAGE

AN UPPER RIDGE WILL RE-POSITION ITSELF OVER NRN MEXICO AND AZ/NM
TO CALM THE MONSOONAL FETCH SOME DURING THE FCST PERIOD.
HOWEVER... AN ARRAY OF SMALL SCALE IMPULSES IS ANTICIPATED TO
ADVECT INTO THE INTER-MOUNTAIN WEST AHEAD OF DECENT THICKNESS
PACKING/FRONTAL ZONE OVER WA/OR. IT STILL APPEARS SOME MID-LEVEL
DYNAMICS WILL STREAM THROUGH CENTRAL CA INTO NV BEFORE PROCEEDING
DOWNSTREAM THROUGH UT INTO CO... WHILE SOME PAC DYNAMICS ORGANIZE
ALONG NRN CA/OR COAST BEFORE MOVING INTO THE INTERIOR NW. REALLY
TOUGH TO GAUGE WHICH MODEL IS HANDLING THESE FEATURES CORRECTLY
BUT THE GFS AND ECMWF SEEM TO BE MOST SIMILAR AND A BLEND OF THESE
TWO SEEMS WISE.


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

MUSHER

$$




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