Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 012049
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
149 PM PDT SAT AUG 1 2015

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

SHORT TERM...UPR LVL LOW PRES W OF THE CENTRAL CAL OFF WTRS THIS
AFTN IS DRIFTING W. THE UPR LVL LOW IS CONTG TO DRAW TROPICAL
MOISTURE N OVR THE OFF WTRS. THE LATEST LIGHTNING DATA AND
SATELLITE IMGRY INDICATES SCTD TSTMS OVR NOCAL AND OREG OFF WTRS.
THIS ACTIVITY MAY PERSIST INTO TONITE AND POSSIBLY SUN...WITH
LOCALLY GUSTY WINDS AND ROUGH SEAS IN OR NEAR ANY TSTMS. THE
LATEST SREF/SPC TSTM GUID SHOWS THE TSTM ACTIVITY PERSISTING
TONITE...INTO SUN...MAINLY OVR NOCAL AND PZ5 OFF WTRS. THE LATEST
ASCAT AND RSCAT DATA INDICATES GENERALLY N WINDS UP TO 25 KT
OCCURRING MAINLY FROM NOCAL WTRS NORTHWARD THIS AFTN WHERE IT
ALSO SHOWS A WEAK LOW PRES CIRCULATION JUST W OF CP MENDOCINO...
WITH WINDS AROUND 20 KT OR LESS FURTHER S OVR SOCAL AND CENTRAL
CAL OFF WTRS. AS THE UPR LVL LOW SLOWLY WEAKENS OVR THE NEXT
COUPLE OF DAYS...THE HIGH PRES AREA CURRENTLY LOCATED NR 40N150W
PER THE 18Z PRELIM OPC SFC ANALYSIS...WILL SLOWLY BUILD E AND NE
TOWARD THE OFF WTRS. AS THIS OCCURS THE PRES GRAD BETWEEN THE
HIGH AND A DVLPG COASTAL TROF WILL STRENGTHEN LEADING TO AN
INCREASE IN N TO NW WINDS OVR THE OFF WTRS BY TUE INTO WED.

LONG TERM...IT APPEARS THAT THE PRES GRAD WILL CONT TO STRENGTHEN
BETWEEN THE HIGH BUILDING E TOWARD THE OFF WTRS AND A LOW PRES
TROF ALONG THE CALIF AND OREG COAST LATE WED THRU THU INTO THU
NITE. WE WILL GO AHEAD AND ADD MINIMAL GALES FOR INNER NOCAL OFF
WTRS FOR THU NITE AS A RESULT...WITH CONFDC IN THESE GALES NR
AVERAGE AT THIS TIME.

MODELS...OVERALL...THE 12Z GLBL MDLS ARE IN VRY GOOD AGREEMENT
OVR THE OFF WTRS FOR THE NEXT 3-5 DAYS. BASED ON THE LATEST HIRES
ASCAT-B PASS AND HIRES R-SCAT PASSES IT APPEARS AS IF A BLEND OF
THE 10M GFS AND 30M GFS WINDS WILL BEST FIT THE CURRENT AND FCST
WIND FIELD EXPECTED OVR THE OFF WTRS TONITE THRU THU NITE. WE
WILL TWEAK THE GRIDS FROM THIS BLEND SLIGHTLY TO LIMIT GALES TO
ONLY INNER NOCAL OFF WTRS...OR ZONE PZZ820...FOR THU NITE...AS WE
DO NOT FEEL CONFDC ENUF AT THIS TIME TO ALLOW GALES TO EXPAND
FROM NOCAL INTO SE OREG OFF WTRS. WE WILL CONT TO MONITOR THIS
POTENTIAL OVR THE NEXT FEW DAYS...AND PSBLY ADD GALES TO THESE
WTRS IN FUTURE FCSTS.

.SEAS...PER THE LATEST RP1 OPC SEA STATE ANALYSIS AND ALTIMETER
PASSES OVR THE REGION IT APPEARS AS IF THE 12Z ENP WV WATCH III
MDL GUID HAS INITIALIZED QUITE WELL OVR THE OFF WTRS. WE WILL
THEREFORE REMAIN CLOSE TO THE ENP WW3 MDL OUTPUT FOR THE AFTN
FCST PACKAGE. THE WV WATCH III DATA IS ALSO VERY CLOSE TO THE 12Z
ECMWF WAM WV MDL OUTPUT OVR THE WTRS DURING THE NEXT FEW DAYS.

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

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE POSSIBLE THU NIGHT.

$$

.FORECASTER MILLS. OCEAN PREDICTION CENTER.



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