Prognostic Meteorological Discussion
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FXUS10 KWNH 161853
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
253 PM EDT TUE SEP 16 2014

VALID SEP 16/1200 UTC THRU SEP 20/0000 UTC

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

12Z MODEL EVALUATION...INCLUDING THE NAM/GFS/UKMET/GEM AND ECMWF


...TROPICAL STORM ODILE...

PREFERENCE: THE LATEST NHC TRACK FORECAST

T.S. ODILE CONTINUES TO LIFT NORTH-NORTHWEST UP THROUGH THE BAJA
PENINSULA AS PER THE LATEST NHC ADVISORY...AND A TURN TO THE
NORTH-NORTHEAST WITH A DECREASE IN FORWARD SPEED IS EXPECTED OVER
THE NEXT 24 HOURS. THIS WILL ALLOW THE SYSTEM TO MOVE OVER THE
NORTHERN GULF OF CA AND THEN MOVE INLAND OVER NORTHERN PORTIONS OF
NORTHWEST MAINLAND MEXICO. THE 12Z GFS IS THE FASTEST
SOLN...FOLLOWED BY THE 12Z ECMWF AND 12Z UKMET. THE 12Z NAM
INITIALLY IS FARTHER NORTH AND FASTER THAN THE GFS/ECMWF
SOLNS...BUT GRADUALLY THE NAM BECOMES TOO SLOW WITH THE MID LEVEL
ENERGY LIFTING NORTHEAST ACROSS SOUTHEAST AZ AND INTO NM. THE 12Z
GEM BECOMES TOO SLOW LIKE THE NAM. GIVEN THE TRENDS IN THE ECMWF
TO BE FASTER LIKE THE GFS...AND WITH THE GFS STILL TRENDING A
LITTLE MORE PROGRESSIVE...A SOMEWHAT MORE PROGRESSIVE SOLN APPEARS
REASONABLE SUCH AS A BLEND OF THE GFS AND ECMWF. THIS APPLIES TO
THE MID LEVEL ENERGY OF ODILE WHICH IS EXPECTED TO SEPARATE AWAY
FROM THE LOW LEVEL CENTER OVER THE NEXT COUPLE OF DAYS. THE LOW
LEVEL CENTER SHOULD SLOW DOWN AND THE PREFERRED TRACK OF THIS WILL
BE COMPARABLE TO A BLEND OF THE 12Z ECMWF AND 12Z UKMET WHICH ALSO
APPEARS CLOSEST TO THE LATEST NHC FORECAST TRACK.


...DEEP UPPER TROUGH AFFECTING THE WESTERN STATES WED TO FRI...

PREFERENCE: BLEND OF THE 12Z UKMET/12Z GEM AND 12Z ECMWF
CONFIDENCE: AVERAGE

THE UPPER RIDGE INITIALLY POSITIONED OVER THE WESTERN U.S. WILL
SHIFT EASTWARD AHEAD OF A BROAD UPPER TROUGH OFFSHORE THE WEST
COAST THAT WILL BE DIGGING INTO THE SOUTHWEST U.S. BY FRI. THE 12Z
GEM/12Z UKMET AND 12Z ECMWF ARE A LITTLE SLOWER AND STRONGER THAN
THE 12Z NAM AND 12Z GFS SOLNS. THERE HAS BEEN A BIT OF A TREND TO
SLOW DOWN THIS ENERGY AS IT MOVES INTO THE SOUTHWEST AS IT WILL BE
ATTEMPTING TO SEPARATE OUT AWAY FROM THE WESTERLIES FARTHER NORTH.
WILL PREFER A SOMEWHAT SLOWER/DEEPER SOLN LED BY A NON-NCEP MODEL
CONSENSUS.


...UPPER TROUGH OVER NORTHEASTERN NORTH AMERICA...
...STRONG COLD FRONT MOVING THROUGH THE NORTHEAST ON WED...

PREFERENCE: BLEND OF THE 12Z ECMWF AND 12Z GEM
CONFIDENCE: AVERAGE

AN AMPLIFIED UPPER PATTERN REMAINS IN PLACE ACROSS MUCH OF THE
NORTHEAST U.S. AND SOUTHEAST CANADA. THE 12Z NAM/12Z GFS AND 12Z
UKMET ARE A LITTLE SLOWER/DEEPER THAN THE 12Z GEM AND 12Z ECMWF.
THE LATEST GEFS MEAN AND ESP THE ECENS MEAN ARE A TAD FASTER
THOUGH LIKE THE GEM/ECMWF CAMP...AND SO A BLEND OF THE ECMWF AND
GEM WILL BE PREFERRED ATTM.


...UPPER TROUGH DIGGING INTO THE NORTHERN PLAINS ON FRI...

PREFERENCE: BLEND OF THE 12Z GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE

ALL OF THE MODELS INDICATE A TROUGH DIGGING INTO THE NORTHERN
PLAINS ON FRI ALONG WITH A COLD FRONT. THE 12Z NAM AND 12Z UKMET
ARE SLIGHTLY MORE PROGRESSIVE WITH THE HEIGHT FALLS WITH THE 12Z
GFS/12Z ECMWF AND 12Z GEM A LITTLE SLOWER. THE GEFS MEAN AND ECENS
MEAN ARE A LITTLE SLOWER LIKE THE GFS/ECMWF/GEM CAMP. WILL FAVOR A
BLEND OF THE 12Z GFS AND 12Z ECMWF ATTM.


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

ORRISON

$$





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