000
AGPN40 KWNM 132049
MIMPAC
MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
150 PM PST WED 13 FEB 2013
.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.
PER 18Z NCEP PRELIM SFC ANALYSIS A WARM FRONT WAS OVER THE PZ5
WATERS W/A HIGH PRES RIDGE OVER THE PZ6 WATERS. A LOW PRES
TROUGH CONTINUED ALONG THE CA COAST. 1728Z ASCT HIRES PASS DIDNT
CAPTURE DATA FROM THE PZ5/NRN CA WATERS AND MOST OF THE CENTRAL
CA WATERS. BUT IN THE SE CENTRAL CA WATERS IT INDICATED 15-20 KT
WINDS AND 10-15 KT WINDS IN THE CENTRAL PART OF THE SRN CA
WATERS.
12Z GUIDANCE REMAINS IN GOOD AGREEMENT OVER THE PERIOD. WARM
FRONT OVER THE PZ5 WATERS LIFT NWD TONIGHT ALLOWING THE HIGH
PRES RIDGE TO EXPAND N...WHILE ALSO REMAINING OVER THE REST OF
THE OFFSHORE WATERS. BY FRI THE RIDGE BEGINS TO WEAKEN ACROSS
THE OFFSHORE WATERS IN RESPONSE TO A COLD FRONT APPROACHING THE
PZ5 AREA FROM THE W. GUIDANCE IS IN GOOD AGREEMENT CONCERNING
THE FRONT WEAKENING AS IT MOVE THROUGH THE N PZ5 WATERS LATE FRI
INTO SAT. THE RIDGE REBUILDS ACROSS THE WATERS DURING THE
REMAINDER OF THE WEEKEND WHILE ALSO INTERACTING W/A LOW PRES
TROUGH ALONG THE CA COAST. 12Z GFS/CMC HAVE BACKED OFF ON THE
COVERAGE OF GALES IN THE NRN/CENTRAL CA WATERS SOME AND SUGGESTS
ANY GALES WOULD BE MORE CONFINED TO THE COASTALS. ADDITIONALLY
THE 12Z ECMWF HAS BACKED OFF ON ITS COVERAGE OF 30 KT WINDS.
MEANWHILE THE 12Z UKMET CONTINUES W/A SPATIAL COVERAGE OF 30 KT
WINDS SIMILAR TO ITS 00Z RUN. THAT SAID WILL CONTINUE W/SUN
GALES IN THE NRN/CENTRAL CA WATERS THOUGH CONFDC WILL REMAIN
LOW. IF GUIDANCE CONTINUES TO TREND DOWNWARD WILL HAVE TO
CONSIDER DROPPING GALE WORDING IN FUTURE FORECAST.
BY DAY 5 ANOTHER FRONTAL BOUNDARY IS EXPECTED JUST W OF THE
WATERS W/LOW PRES DEVELOPING ALONG THE FRONT AND DIVING SE
W/SUPPORT FROM THE 12Z GFS/ECMWF/UKMET/CMC. 12Z GFS/UKMET/CMC
INDICATE 35 KT WINDS IN THE SW QUAD OF THE LOW W/THE 12Z ECMWF
AT 30 KT. THE GFS/CMC BRING GALES INTO THE FAR W OR/NRN CA
WATERS DAY 5 WHILE THE UKMET...AND ECMWF W/ITS 30 KT
WINDS...REMAIN W OF THE WATERS. FOR NOW FEEL ITS REASONABLE TO
MENTION MOVEMENT OF LOW INTO THE PZ5 WATERS IN THE
SYNOPSIS...BUT KEEP WINDS JUST BELOW GALE STRENGTH GIVEN ITS DAY
5. WOULD WANT TO SEE AT LEAST ANOTHER MODEL CYCLE OR TWO TO SEE
IF GUIDANCE CONTINUES W/TREND OF BRINGING GALES INTO THE WATERS
MON.
12Z NWW3/ECMWF FARED WELL WHEN COMPARED TO 12/18Z BUOY/SHIP
OBS...THEREFORE WILL GENERALLY FAVOR NWW3 VALUES OVER THE
FORECAST PERIOD...THOUGH ON DAY 5 PROBABLY REMAIN JUST A BIT
UNDER GUIDANCE GIVEN CHOICE TO KEEP STRONGER WINDS ASSOCIATED
W/THE EXPECTED LOW PRES...JUST W OF THE WATERS.
EXTRATROPICAL STORM SURGE MODEL...N/A.
.WARNINGS/FORECAST CONFIDENCE...PRELIMINARY. ANY CHANGES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:
.PZ5 WASHINGTON/OREGON WATERS...
CAPE FLATTERY TO CAPE LOOKOUT...NONE.
CAPE LOOKOUT TO PT ST GEORGE...NONE.
.PZ6 CALIFORNIA WATERS...
PT ST GEORGE TO PT ARENA...GALE SUN...LOW CONFDC.
PT ARENA TO PT CONCEPTION...GALE SUN...LOW CONFDC.
PT CONCEPTION TO GUADALUPE ISLAND...NONE.
$$
.FORECASTER HOLLEY. OCEAN PREDICTION CENTER.