Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 231355
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
655 AM PDT SAT AUG 23 2014

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.

CRNT FCST LOOKS ON TRACK. SOME MINOR DIFFS LT IN THE PERIOD WITH A
CLD FRNT MOVING INTO THE PZ05 WTRS AND THIS MAY POSE A FCST
CHALLENGE IN LATER UPDATES. FOR NOW WL REFRESH THE GRIDS W/THE
LATEST MDL DATA...GFS 30M WNDS THRU 27/12Z THEN ALL ECMWF...SEAS
WAM/WW3 BLEND THRU 27/12Z THEN ALL WAM.

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PREVIOUS DISCUSSION...

OVER THE SHORT TERM...THE NEW 00Z MDLS ARE IN RSNBLY GOOD AGRMT
THAT A STRONG HIGH PRES CENTER WL REMAIN IN PLACE W OF THE PZ5
WTRS WHL THE INLAND LOW PRES TROF OVER CA STRENGTHENS AND EXPANDS
NWD TODAY THRU SUN/SUN NITE WHICH WL SUPPORT A MOD STRONG
(PRIMARILY 20-30 KT) NNWLY GRADIENT ACRS THE NRN PZ6 WTRS AND WL
EXPAND NWD THRUT MOST OF THE PZ5 WTRS. OVERALL THE 00Z GFS 30M BL
WINDS LOOK REPRESENTATIVE FOR THIS FCST GRADIENT. THESE 00Z GFS
30M BL WINDS...WHICH ARE SUPPORTED BEST BY THE 00Z NAM/GEM...ALSO
INDICATE THAT MARGINAL GALES CULD DVLP IN THIS GRADIENT IN THE
CSTL WTR DOMAINS NEAR PT ST GEORGE. FOR NOW WITH THE 00Z
UKMET/ECMWF FCSTG SLIGHTLY WEAKER GRADIENTS WL HOLD OFF ON FCSTG
ANY GALE WRNGS FOR THE ADJACENT OFSHR WTRS. THEREFORE PLAN ON
POPULATING OUR SHORT TERM WIND GRIDS WITH THE 00Z GFS 30M BL WINDS
WITH SM ADDITIONAL MINOR EDITS THEN MADE IN DEFERENCE TO THE 00Z
UKMET/ECMWF BL WINDS. SO SINCE THE 12Z GFS 30M BL WINDS WERE
PREVLY USED DO NOT ANTICIPATE MAKING ANY MAJOR SHORT TERM CHNGS TO
THE PREV OFSHR FCSTS.

IN THE LONG RANGE...THO THE 00Z MDLS HV SM TIMING DIFFERENCES...
IN RESPONSE TO A WEAK COLD FRONT APRCHG FM THE NW THEY ALL FCST
THE HIGH PRES CENTER TO GRADLY WEAKEN...WHL ALSO WKNG THE INLAND
SFC TROF...WHICH WL RESULT IN THE NNW GRADIENT OFSHR TO GRADLY
WEAKEN MON INTO TUE NITE. PLAN ON CONTG TO USE THE 00Z GFS 30M BL
WINDS FOR THIS WEAKENING GRADIENT THRU TUE NITE...WITH AGAIN SM
FURTHER EDITS IN DEFERENCE TO THE 00Z ECMWF. THEN WL TRANSITION TO
POPULATING WITH THE 00Z ECMWF BL WINDS FOR WED/WED NITE SINCE
PREFER ITS SOLUTION OVER THE NRN WTRS WITH THE COLD FRONT WASHING
OUT AS IT ENTERS THE PZ5 WTRS. ANOTHER REASON TO POPULATE WITH THE
00Z ECMWF ON WED/WED NITE IS THAT ITS FCST TRACK IS THE CLOSEST OF
ALL THE 00Z GLOBAL MDLS TO THE LATEST NHC FCST TRACK FOR WHAT IS
THEN EXPECTED TO BE HURCN MARIE PASSING S OF THE PZ6 WTRS. SO
OVERALL NO MAJOR LONG RANGE CHNGS ARE PLANNED FOR THE NEXT OFSHR
FCST PACKAGE.

.SEAS...LONG PERIOD SLY SWELL FM T.S. LOWELL ARE ALREADY IMPACTING
THE SRN PZ6 WTRS AND ARE INITIALIZED RSNBLY WELL BY THE 00Z
WAVEWATCH III AND 00Z ECMWF WAM MDLS. WITH THE DIFFENCES BTWN THE
TWO MDLS NOT EXCEEDING 1-2 FT WL USE A 50/50 BLEND OF THE TWO MDLS
TODAY THRU TUE NITE. THEN WL TRANSITION TO AN ALL 00Z ECMWF WAM
SOLUTION FOR WED/WED NITE MAINLY TO KEEP THE SEAS LOWER OVER THE
SRN PZ6 WTRS THAN FCST BY THE 00Z WAVEWATCH III.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A.

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER LEE/VUKITS. OCEAN PREDICTION CENTER.


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