Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 020346
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
846 PM PDT TUE SEP 1 2015

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

THE CURR SAT IMG INFERS CONV OVR THE NRN WTRS AND THE FAR SRN
PARTS BUT WITH ALMOST NO LITGNG STRIKES. THE RADAR HAS NO INDC OF
TSTMS CELLS OVR THE REGION. THERE IS A 30 PERCNT CHNC OF TSTMS OVR
THE NRN WTRS IN THE SHORT TERM. AT 00Z HGH PRES 1030 MB OVR THE
CNTRL PAC HAS RIDGE ONTO THE SRN WTRS WHILE CLD FRNT THAT
STRCTCHES FRM LOW PRES OVR CANADA COAST LIES ACRS THE NRN WTRS.
INLAND TROF STRCHES ALONG FRM SRN CA TO THE NRN CA. THE PRES GRDNT
IS WEAK AND MAX OBS WINDS ARE 15 KT. MEANWHILE THE LAST ASCAT PASS
AT 1824 HAD 20 KT WINDS OVR THE NW PARTS WITH GALE FORCE WINDS
JUST NW OF THE REGION. THE SEAS ARE HGHST OVR THE NW PARTS OF THE
NRN WTRS WITH 12 FT PEAK WHILE THEY RANGE BTWN 7 AND 10 FT
ELSEWHERE.

MOST OF THE ENRGY IS EMBDD IN AN UPPLVL LOW PRES TROF JUST NW OF
THE REGION WHILE THE REST OF THE TROF XTNDG TO JUST W OF THE SRN
WTRS HAS VERY LITLE ENRGY. AN UPPRLRVL RIDGE LIES TO THE W OF THE
UPPLVL TROF. THERE SI VERY LITTLE ENERGY OVR THE SRN CA THAT HAS
MAINTAINED THE INLAND TROF. MOST OF THE ERNGY WILL SHIFT SE AND
PASS ACRS THE N-ERN PARTS OF THE WTRS AND THAT WILL ALLOW THE CLD
FRNT ACRS THE ENR WTRS TO PERSIST AS IT SLOWLY MOVES SE. XPCT THE
PRES GRDNT TO TIGHTEN BUT NOT ENOUGH TO GENERATE GALE FORCE WINDS
OVR THE WTRS. WINDS WILL BE ELEVATED TO JUST BELOW GALE FORCE.

THE GLBL MDLS HV CONTINUED TO INITALIZE WELL WITH THE CURR OBS AND
THEY HV BEEN QUITE COSSTNT IN THE PREVIOUS RUNS. THE ONLY PROBLEM
IS THAT THEY SLIGTHLY DIFFER ON THE STRENGTH AND SPEED OF THE LOW
PRES TRACK THAT WILL PASS ACRS THE ERN PARTS OF THE NRN WTRS.
OTHER WISE THESE MNR DIFFS ARE MEAGRE AND SO WILL CONTINUE WITH
GFS. IN THE SHORT TERM THE LOW PRES TO THE N OVR CANADA COAST WILL
MOVE E INLAND AND THAT WILL ALLOW THE ASSOCTD GALE FORCE WINDS TO
DIMINSH OVER THE AREA TO THE NW OF THE REGION. THE HGH PRES OVR
THE PAC WILL DRIFT E AT ABOUT THE SAME STRENGTH WHILE THE INLAND
TROF WILL PERSIST...AND THAT WILL FORCE THE ISOBARS BTWN THE TWO
FEATURES TO PACK UP AND ENHANCE THE WINDS OVR THE ERN PARTS OF THE
CNTRL REGION. OTHERWISE WINDS SHUD REMAIN BELOW GALE FORCE EVEN
INTO THE XTNDD PRD ACRS THE BOARD.

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

AN AREA OF LOW PRESSURE OVER HAIDA GWAII WAS ANALYZED TO 996
MB ON THE OPC/NCEP SFC ANALYSIS...WITH SIGNIFICANT WAVE HEIGHTS
TO 16 FT ON THE 18Z RP1 SEA STATE ANALYSIS. WILL CONTINUE TO PUSH
E THROUGH TOMORROW BRINGING SOME CHANCES FOR RAIN AND SCATTERED
TSTORMS ACROSS THE PZ5 ZONES. MODELS ARE IN GOOD AGREEMENT WITH
THE AREA OF LOW PRESSURE ANALYZED OVER HAIDA GWAII TRACKING SE
ALONG THE COAST BEFORE MOVING INLAND AND DISSIPATING WEDNESDAY
NIGHT. WINDS WILL INCREASE TO 30 KT IN THE NORTHERN WATERS BEFORE
DIMINISHING AS THE LOW DISSIPATES. AN AREA OF LOW PRESSURE NORTH
OF THE AREA WILL DRAG A COLD FRONT THROUGH THE NORTHERN WATERS
SATURDAY NIGHT THROUGH SUNDAY NIGHT. OTHERWISE A FAIRLY TYPICAL
SUMMER PATTERN TO PREVAIL THURSDAY AND BEYOND AS HIGH PRESSURE
BEGINS TO BUILD EAST AND PERSISTS WEST OF THE AREA...AS A LOW
PRESSURE TROUGH DEVELOPS ALONG THE CALIF COAST GENERATING
SEASONAL N-NW WINDS ACROSS THE BULK OF THE OFFSHORE ZONES.

MODELS WERE IN GOOD AGREEMENT THROUGHOUT THE FORECAST PERIOD AND
HAVE REMAINED FAIRLY CONSISTENT...WITH ONLY SOME MINOR DIFFERENCES
IN THE FORECAST TRACK OF THE LOW PRESSURE SATURDAY NIGHT THROUGH
SUNDAY NIGHT. USED THE 12Z GFS WITH SOME MINOR CHANGES FOR THE
FORECAST.

SEAS...SINCE USING THE 12Z GFS THRUT WILL USE THE 12Z ENP AS WELL. THE
NORTHERN ZONES WILL SEE SOME 14 FT SEAS THROUGH WEDNESDAY NIGHT.
SEAS WILL INCREASE ALONG THE CALIFORNIA COAST AS A COASTAL LOW
PRESSURE TROUGH STRENGTHENS OVERNIGHT WEDNESDAY THROUGH SUNDAY.


.EXTRATROPICAL STORM SURGE GUIDANCE...N/A



.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER MUSONDA/SOMMERVILLE. OCEAN PREDICTION CENTER.



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