Prognostic Meteorological Discussion
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000
FXUS10 KWNH 160650
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
249 AM EDT TUE SEP 16 2014

VALID SEP 16/0000 UTC THRU SEP 19/1200 UTC

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

00Z MODEL EVALUATION ALONG WITH PREFERENCES/CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

THERE DID NOT APPEAR TO BE ANY INITIALIZATION ERRORS WITH THE 00Z
NAM/GFS DEEMED SIGNIFICANT ENOUGH TO IMPACT THEIR FORECASTS.


FULL LATITUDE TROF OVER NORTHEASTERN NORTH AMERICA
STRONG COLD FRONT MOVING THROUGH THE NORTHEAST ON WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/ECMWF
CONFIDENCE: AVERAGE

AN AMPLIFIED UPPER PATTERN REMAINS IN PLACE ACROSS MUCH OF THE
NORTHEASTERN SECTOR OF THE CONTINENT WITH A BAND OF HEIGHT FALLS
TRAVERSING THROUGH THE UPPER MID-ATLANTIC EARLY TUESDAY MORNING.
ALL MODELS AGREE THIS ENERGY WILL RACE UP TOWARD FAR EASTERN
CANADA WITH ADDITIONAL ENERGY DIGGING UPSTREAM TOWARD
ONTARIO/QUEBEC. AT THE SURFACE...THE MODELS HAVE MADE A FEW
CHANGES WITH THE 00Z GFS/UKMET APPEARING TO BE THE FASTER
SOLUTIONS WHILE THE 00Z ECMWF HAS TRENDED SLOWER MORE TOWARD THE
00Z NAM. WILL SPLIT THE DIFFERENCE BETWEEN THE TWO CAMPS WITH THE
RECOMMENDATION REMAINING THE SAME AS PREVIOUS. THE CONFIDENCE HAS
BEEN LOWERED SLIGHTLY GIVEN THE SUBTLE INCREASE IN SPREAD.


WEAK SURFACE WAVE MOVING INTO SOUTH TX EARLY TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: A NON-00Z NAM MODEL CONSENSUS
CONFIDENCE: ABOVE AVERAGE

A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY REACH SOUTH TX BY
EARLY TUESDAY. THE 00Z NAM IS PERHAPS A LITTLE FASTER WITH ITS
SOLUTION WHILE OTHER MODELS IN FAIRLY GOOD AGREEMENT. WILL
RECOMMEND A NON-00Z NAM MODEL CONSENSUS.


STALLED FRONT/SURFACE WAVES ACROSS THE SOUTHEASTERN U.S.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 03Z WPC SURFACE ANALYSIS SHOWED A BOUNDARY STALLED ACROSS THE
DEEP SOUTH AND THROUGH THE SOUTHEASTERN U.S. THIS BOUNDARY WILL
SLOWLY NOSE SOUTHWARD AND REMAIN A FOCUS FOR CONVECTION THE NEXT
COUPLE OF DAYS ALONG THE GULF COAST REGION. MODELS ARE FAIRLY
CLOSE TO ANOTHER WITH THE 00Z CMC NOW JOINING THE STRONGER
CONSENSUS. WILL SHIFT OVER TO A GENERAL MODEL COMPROMISE IN THAT
CASE.


DEEP UPPER TROF AFFECTING THE WESTERN STATES WED-FRI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/ECMWF
CONFIDENCE: AVERAGE

THE UPPER RIDGE INITIALLY POSITIONED OVER THE WESTERN U.S. WILL
ADVANCE EASTWARD AHEAD OF A BROAD AREA OF HEIGHT FALLS MOVING
TOWARD THE COAST. THE CORE OF THE LOWEST HEIGHTS WILL CROSS 130W
BY WEDNESDAY MORNING WITH THE 00Z CMC WEST OF THE ENSEMBLE MEANS
AT THIS POINT. THE CMC HAD THIS BIAS LAST NIGHT AS WELL. BY
THURSDAY...THE SYSTEM SPLITS WITH SOME ENERGY JOINING THE NORTHERN
STREAM WHILE A CORE OF THE VORTICITY DIGS INTO NORTHERN/CENTRAL
CA. THE ENSEMBLE MEANS REMAIN A STEADY SOLUTION THROUGHOUT THE
EVOLUTION WITH THE 00Z GFS/ECMWF PROVIDING A REASONABLE
REPRESENTATION OF THESE MEANS. A 00Z GFS/ECMWF BLEND WILL BE THE
PREFERENCE.


TROPICAL STORM ODILE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/ECMWF/UKMET THROUGH
17/1200Z...00Z ECMWF THEREAFTER

RECENTLY DOWNGRADED TO A TROPICAL STORM...ODILE CONTINUES TO DUMP
VERY HEAVY RAINFALL ACROSS BAJA CA WITH ITS MOISTURE EVENTUALLY
LIFTING INTO THE DESERT SOUTHWEST AND FOUR CORNERS REGION. DURING
THE FIRST 12 HOURS OF THE FORECAST...THE 00Z CMC/12Z ECMWF
ENSEMBLE MEAN DIVERGE FROM THE NHC TRACK RELATIVELY QUICKLY.
EVENTUALLY THE SYSTEM IS EXPECTED TO MAKE A TURN TOWARD THE
NORTHEAST CROSSING THE GULF OF BAJA CA/SEA OF CORTEZ BY EARLY
WEDNESDAY. THROUGH 36 HOURS...17/1200Z...SOME COMBINATION OF THE
00Z GFS/ECMWF/UKMET APPEARS TO BE A REASONABLE COMPROMISE TO THE
NHC FORECAST. THEREAFTER...THE 00Z GFS BECOMES QUICKER AND OFF TO
THE WEST WHILE THE 00Z UKMET ALSO BEGINS TO LEAVE THE CLUSTERING.
THE 00Z ECMWF SEEMS TO DO THE BEST JOB AFTER 17/1200Z SO WILL
INCORPORATE THAT SOLUTION IN THE PREFERENCE.


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


RUBIN-OSTER

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