Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 310345
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
845 PM PDT WED JUL 30 2014

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

THERE WAS A JASON PASS OVR THE CNTRL AND SRN AREAS OF THE CA WTRS
AT ARND 23Z. SEAS WERE CLOSE TO WWIII AND ECMWF WV GUID OVR THIS
AREA. THERE WAS A SHIP OBS WITH 7 FT OVR THE SRN CA WTRS AT 00Z
WHICH APRS TO BE A CPL OF FT HIER THAN ALTIMETER INDICATES OVR
THIS AREA.

HIGH PRES RMNS TO THE W AND SW OF THE NRN OFFSHR WTRS AND RMNS
INTO SUN NGT BEFORE WEAKENING ACRS THE WA/OR WTRS MON AND MON NGT.
COASTAL TROF ALG THE NRN AND CNTRL CA WTRS INTENSIFIES SOMEWHAT
TNGT AND CHANGES LTL IN INTENSITY THRU ABT SUN NGT.
GFS/UKMET/ECMWF LOOK SMLR WITH TRENDS THRU ABT SUN NGT WITH WINDS
TO 30 KT OVR THE ERN AREAS OF THE NRN CA WTRS. BY MON INTO MON NGT
MDLS DIFFER WITH THE ECMWF MOVG A CD FNT SE OVR THE WA/OR WTRS
WHILE GFS HAS FNT FURTHER N. PREFER THE ECMWF WHICH STARTS TO WKN THE
COASTAL TROF ALG CA AS THE FNT MOVS SE OVR THE WA/OR WTRS LATE MON
AND MON NGT.

OVERALL WL BE MAKING MINOR ADJSTMTS TO FCST GRIDS AND HAV ADDED A
CHANCE OF SHWRS OF THE ERN AREAS OF THE WA WTRS TNGT. MDL GUID
DOES NOT DEPICT THIS WELL. OTW THERE WL FEW CHANGES TO FCST GRIDS
THRU THE PD.

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

SUMMARY...A LARGE UPR LVL LOW PRES AREA OVR THE WRN GULF OF AK
WILL REMAIN NRLY STNRY INTO THE WKND...AND THEN SLWLY MOVE NE SUN
INTO THE MIDDLE OF NEXT WK. UPR LVL HIGH PRES WILL PERSIST OVR
THE WRN STATES INTO THE WKND BEFORE IT WEAKENS NEXT WK. AT THE
SFC A WK STNRY FRONT OVR PZ5 WTRS WILL DSIPT EARLY TNGT. THE FCST
WTRS WILL REMAIN BETWEEN HIGH PRES NR AND W OF THE OFF WTRS AND A
LOW PRES TROF NR THE W COAST THRU THE WKND INTO EARLY NEXT WK.
THE LATEST OBS AND ASCAT DATA INDICATES MAX WINDS TO 30 KT
OCCURRING OFF THE NOCAL COAST EARLY THIS AFTN. IT APPEARS AS IF
THERE WILL BE A SLIGHT CHANCE FOR GALES DVLPG OVR THE FAR ERN
NOCAL OFF WTRS SUN INTO EARLY MON AS THE TROF INTENSIFIES. AT
THIS TIME...THE CHANCES ARE TOO LOW TO ADD TO THE OFF FCST...BUT
OPC WILL CONT TO MONITOR THIS POTENTIAL OVR THE NEXT FEW DAYS.
OTW...A WKNG COLD FRONT WILL APPROACH PZ5 WTRS FROM THE W EARLY
MON...AND THEN PUSH SE OVR THESE WTRS LTR MON INTO MON NGT.

MODELS...THE 12Z MDLS REMAIN IN DECENT AGREEMENT ACROSS THE REGION
TNGT INTO SAT NGT...AND THEN SOME DIFFERENCES ARE NOTED MAINLY W
OF THE OFF WTRS SUN INTO MON NGT. WE WILL STAY CLOSE TO THE 12Z
GFS FOR TNGT THRU SAT NGT...AND THEN TRANSITION TO THE 12Z ECMWF
HI-RES MDL GUID THEREAFTER AS IT IS IN BETTER AGREEMENT WITH THE
REMAINING NON-GFS MDL GUID FOR SUN INTO NEXT WK OVR THE E PAC.

SEAS...THE 12Z ECMWF-WAM WV GUID APPEARS TO HAVE INITIALIZED A TAD
BETTER THAN THE 12Z WW3 MDL GUID THIS AFTN OVR THE E PAC. MAX SEA
HTS NR 10 FT ARE NOTED OFF THE NOCAL COAST PER THE LATEST RP1 OPC
SEA STATE ANALYSIS AND ALTIMETER DATA. THE ECMWF WAM ALSO APPEARS
TO BUILD SEAS A BIT FASTER...AND A LITTLE HIGHER THAN THE WW3 OVR
ERN NOCAL AND CENTRAL CAL WTRS BY THE WKND AS THE WINDS INCREASE
SOMEWHAT. AS A RESULT...WE WILL MORE CLSLY FOLLOW THE 12Z ECMWF
WAM WV GUID FOR THE AFTN PACKAGE...AND MAKE MINOR ADJUSTMENTS
INITIALLY TO FIT CURRENT CONDITIONS.

.EXTRATROPICAL STORM SURGE GUIDANCE...NA


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER ROWLAND/MILLS. OCEAN PREDICTION CENTER.


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