Marine Interpretation Message
Issued by NWS

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000
AGPN40 KWNM 251508
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
808 AM PDT THU AUG 25 2016

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

ATTM I DONT PLAN ON MAKING ANY CHANGES TO THE CURRENT GRIDS OR
ASSOCIATED TEXT FCST. THE LATEST ASCAT PASS INDICATES WINDS
GENERALLY NW 5-15 KT ACROSS THE WATERS WITH MAX SEAS NR 10 FT JUTS
W OF THE WA/OR WATERS.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

0500Z AND 0540Z ASCAT OVERPASSES ACROSS THE OFFSHORE WATERS
INDICATED HIGHEST WINDS TO 25 KT OVER OUTER PZ5 WATERS N OF 43N.
ELSEWHERE WERE ALSO 25 KT RETURNS INVOF THE CHANNEL ISLANDS BUT
WERE LIMITED TO THE COASTAL ZONES. 00Z MODELS WERE WELL
INITIALIZED WITH WINDS ACROSS THE PZ5 AND NRN PZ6 WATERS...BUT
WERE SLIGHTLY DEFICIENT WITH THE AFOREMENTIONED 25 KT NEAR THE
CHANNEL ISLANDS. ACROSS THE IMMEDIATE OFFSHORE AND COASTAL ZONES
THE 00Z MODELS ARE IN ABOVE AVERAGE AGREEMENT FOR THE NEXT FEW
DAYS. STRONG HIGH PRES NEAR 49N141W SHOULD CONTINUE TO MIGRATE
WESTWARD WHILE WEAKENING...WHILE LATEST GUIDANCE ALL INDICATE
THAT WEAK LOW PRES SHOULD DEVELOP ALONG THE NRN CA COAST LATE
TODAY/TONIGHT AND SLOWLY DRIFT SSW ACROSS PZ6 WATERS FRI THROUGH
 SAT NIGHT BEFORE DISSIPATING SUN. WITH WEAKENING E PACIFIC HIGH
PRES AND THIS WEAK LOW DEVELOPMENT SHOULD SEE A DIMINISHING
TREND WITH THE OFFSHORE WINDS OVER THE WEEKEND.

ALTHOUGH THERE ARE THEN TIMING DIFFERENCES WITH A MID/UPPER
LEVEL TROF DROPPING S AND APPROACHING THE PZ5 WATERS
FRI/SAT...AT THE SURFACE MODELS ARE SIMILAR IN DEPICTING A
DEVELOPING SURFACE LOW WILL MOVE SSE NEAR VANCOUVER ISLAND WITH
AN ASSOCITED NW SURGE DROPPING S INTO NRN PZ5 WATERS FRI NIGHT
INTO SAT. PLAN TO KEEP OPC CONTINUITY WHICH FAVORED THE SLIGHTLY
HIGHER GFS WITH WINDS BRIEFLY TO 30 KT N OF CAPE SHOALWATER FRI
NIGHT. WILL BE POPULATING WITH THE 00Z GFS 10M WINDS THROUGH SAT
NIGHT. BY SUN THROUGH EARLY NEXT WEEK MODELS ALL SHOW A WEAK
COLD FRONT WILL APPROACH AND MOVE SE ACROSS THE PZ5 WATERS.
LATEST GFS LOOKS A BIT SUSPECT IN DEVELOPING MULTIPLE WEAK LOWS
ALONG THE FRONT SUN/MON. 00Z ECMWF TIMING IS BETTER SUPPORTED BY
00Z GEFS. AM THEN FAVORING THE 00Z ECMWF SUN THROUGH EARLY NEXT
WEEK.

THE 00Z WAVEWATCH III WAS WELL INITIALIZED WITH E PACIFIC WAVE
HEIGHTS AT 06Z. THE 00Z ECMWF WAM APPEARS A COUPLE FT TOO HIGH
ACROSS OUTER PZ5 WATERS...YET HAS SLIGHLTLY BETTER HANDLE ON
SEAS OFF S CA. A 50/50 BLEND OF THE ABOVE GUIDANCE LOOKS
REPRESENTATIVE FOR TODAY...THEN TRANSITIONED TO 00Z WW3 THROUGH
SAT NIGHT. WITH PREFERENCE FOR ECMWF BEGINNING SUN POPULATED
WITH 00Z ECMWF WAM SUN THROUGH THE REMAINDER OF THE FORECAST
PERIOD.

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


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER SHAW/CLARK. OCEAN PREDICTION CENTER.


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