Prognostic Meteorological Discussion
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000
FXUS10 KWNH 310445
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1244 AM EDT THU JUL 31 2014

VALID JUL 31/0000 UTC THRU AUG 03/1200 UTC

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


00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
TERM FORECASTS.


NORTHWEST/NORTHERN CONTINENTAL DIVIDE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z NAM/00Z GFS/12Z ECMWF BLEND
CONFIDENCE: AVERAGE

THE 12Z UKMET IS STRONGER WITH ENERGY MOVING FROM NV INTO THE
NORTHERN CONTINENTAL DIVIDE FROM THURSDAY INTO SATURDAY THAN SEEN
ON THE OTHER GUIDANCE. THE 12Z CMC TAKES A DEVIANT TRACK WITH
MID-LEVEL ENERGY INTO WASHINGTON/OREGON AND ENDS UP WITH A
STRONGER UPPER TROUGH OVER THE NORTHWEST BY THE WEEKEND. A BLEND
OF THE NAM/GFS/ECMWF APPEARS REASONABLE FOR THIS SECTION OF THE
COUNTRY GIVEN THEIR DECENT AGREEMENT WITH ONE ANOTHER.


UPPER LEVEL LOW OPENING UP AS IT REACHES SRN CALIFORNIA BY SUN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS / 12Z ECMWF BLEND
CONFIDENCE: AVERAGE

THE GFS/ECMWF HAVE GOOD RUN TO RUN CONTINUITY WITH THIS FEATURE
AND WITH THE INTENSIFICATION OF A MID-LEVEL LOW CENTER OVER THE
CA/MX BORDER BY 12Z SUN. THE 00Z NAM APPEARS TOO STRONG WITH THE
MID-LEVEL REFLECTION COMPARED TO THE REMAINING MODELS. THE 12Z
UKMET/CMC SHOW DISAGREEMENT FROM THE GFS/ECMWF AND HAVE LESS
FAVORABLE RUN TO RUN AGREEMENT.


UPPER TROUGH LINGERING IN THE ERN HALF OF THE NATION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

THE GUIDANCE IS IN GOOD AGREEMENT HERE SO A GENERAL MODEL
COMPROMISE IS ADVISED TO SMOOTH OUT SMALLER SCALE DIFFERENCES.


...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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