Prognostic Meteorological Discussion
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000
FXUS10 KWNH 140458
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1257 AM EDT SUN SEP 14 2014

VALID SEP 14/0000 UTC THRU SEP 17/1200 UTC

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

...AN EVALUATION OF THE 00Z NAM/GFS ALONG WITH PRELIMINARY
PREFERENCES/FORECAST CONFIDENCE...

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


...SHORTWAVE LIFTING FROM SOUTHERN QUEBEC INTO FAR NORTHEASTERN
CANADA...

PRELIMINARY PREFERENCE: GENERAL MODEL CONSENSUS
FORECAST CONFIDENCE: HIGH

A PRONOUNCED SHORTWAVE WILL CONTINUE LIFTING TO HIGHER LATITUDES
WHILE EVENTUALLY EXITING THE MAP DOMAIN BY 14/1800Z. MODEL
DIFFERENCES ARE RATHER SMALL SO A GENERAL MODEL CONSENSUS APPROACH
WILL SUFFICE.


...ADDITIONAL HEIGHT FALLS CROSSING THE NORTHERN TIER OF THE
CONUS...
...PROGRESSIVE COLD FRONT...

PRELIMINARY PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF
FORECAST CONFIDENCE: SLIGHTLY ABOVE AVERAGE

ON THE WINGS OF THE INITIAL SHORTWAVE CROSSING SOUTHERN QUEBEC
WILL BE ANOTHER AREA OF HEIGHT FALLS DROPPING THROUGH THE NORTHERN
PLAINS AND EVENTUALLY ACROSS THE GREAT LAKES. THE LEAD IMPULSE IS
FORECAST TO TRACK OVER LAKE SUPERIOR BY 14/1800Z WITH MODELS IN
DECENT AGREEMENT. ADDITIONAL SHORTWAVE ENERGY WILL PROPAGATE
EASTWARD REACHING THE NORTHEASTERN U.S. BY EARLY TUESDAY. THERE
ARE SOME SLIGHT DIFFERENCES IN TIMING AT THIS POINT WITH THE 00Z
NAM/12Z CMC BEING SLOWER THAN THE MORE PROGRESSIVE 00Z GFS/12Z
ECMWF. WILL ERR TOWARD THE FASTER SOLUTIONS GIVEN THE FAST-MOVING
MID-LATITUDE FLOW IN PLACE. THE PREFERENCE IS A 00Z GFS/12Z ECMWF
BLEND.


...EASTERLY WAVES TRACKING TOWARD EASTERN MEXICO...

PRELIMINARY PREFERENCE: INITIAL ENERGY MOVING INTO TX: BLEND OF
THE 00Z GFS WITH THE 12Z ECMWF/UKMET...EASTERLY WAVE EMERGING OFF
SOUTH FL: BLEND OF THE 00Z GFS/12Z ECMWF
FORECAST CONFIDENCE: AVERAGE

A PAIR OF EASTERLY WAVES ARE FORECAST TO IMPACT EASTERN MEXICO
DURING THE PERIOD OF INTEREST. THE FIRST SUCH DISTURBANCE IS
ALREADY MOVING INTO MEXICO WITH SOME OF THE ENERGETICS MIGRATING
TOWARD THE BIG BEND OF TX AND EVENTUALLY INTO THE TX PANHANDLE BY
SUNDAY EVENING. THE 00Z GFS AND 12Z ECMWF/UKMET SHOW A PRETTY
CONSISTENT SOLUTION WHILE THE 12Z CMC IS QUICKER AND THE 00Z NAM
SUGGESTS A WEAKER MID-LEVEL SIGNAL. LOOKING TO THE SECOND AREA OF
INTEREST EMERGING OFF SOUTH FL...MODELS INDICATE A WEAK AREA OF
LOW PRESSURE WILL TRACK WESTWARD ACROSS THE CENTRAL GULF OF
MEXICO. THE 12Z CMC IS THE MOST DEVELOPED RELATIVE TO THE MORE
TAME SOLUTIONS OUT THERE. WILL MAINTAIN THE PREFERENCE FROM THE
INITIAL SYSTEM BUT NOT INCLUDE THE 12Z UKMET AS ITS A BIT EAST OF
THE 00Z GFS/12Z ECMWF IN THE WESTERN GULF OF MEXICO.


...UPPER TROF SETTLING INTO THE EASTERN PACIFIC BY MID-WEEK...

PRELIMINARY PREFERENCE: A NON-00Z GFS SOLUTION
FORECAST CONFIDENCE: SLIGHTLY ABOVE AVERAGE

AN UPPER RIDGE ANCHORING THE WEST COAST WILL GRADUALLY MOVE
EASTWARD AS HEIGHT FALLS APPROACH FROM THE WEST. THE INITIAL
SHORTWAVE SHOULD APPROACH THE PACIFIC NORTHWEST BY LATE MONDAY
WITHIN THE SOUTHWESTERLY FLOW ALOFT. BEHIND IT A MORE PRONOUNCED
SHORTWAVE ENTERS THE MAP WITH DIFFERENCES IN TIMING NOTED. THE 00Z
GFS IS NOTABLY MORE PROGRESSIVE THAN OTHER DETERMINISTIC MODELS AS
WELL AS THE ENSEMBLE MEANS. FOR NOW WILL RECOMMEND A NON-00Z GFS
SOLUTION ASSUMING NO FUTURE 00Z RUNS JOIN THIS IDEA.


...HURRICANE ODILE...

PRELIMINARY PREFERENCE: 12Z ECMWF ENSEMBLE MEAN
FORECAST CONFIDENCE: AVERAGE

HURRICANE ODILE WHICH CURRENTLY HAS MAXIMUM SUSTAINED WINDS OF 95
KNOTS AND WAS MOVING NORTH-NORTHWEST AT 10 KNOTS SHOULD CONTINUE
THIS TRACK PLACING IT PARALLEL TO THE BAJA CA COAST. THROUGHOUT
THE FORECAST...THE 00Z NAM IS SLOWER AND WEST OF THE NHC TRACK
WHILE THE 00Z GFS/12Z ECMWF ARE JUST OFF TO THE WEST. ON THE OTHER
SIDE ARE THE 12Z CMC/UKMET WHICH ARE EAST OF THE TRACK WITH THE
CMC BEING MUCH SLOWER AND MOST AWAY FROM THEIR SOLUTION.
OVERALL...WOULD SAY THE 12Z ECMWF ENSEMBLE MEAN BEST REPRESENTS
THE FORECAST TRACK.



...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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