North Pacific Marine Weather Discussion

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AGPN40 KWNM 201518
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
718 AM PST Wed Feb 20 2019

.FORECAST DISCUSSION...Major features/winds/seas/significant 
.weather for the North Pacific N of 30N and E of 150W.

A weakening cold front dropping south through the PZ6 waters will
bring a period of winds to 30 kts to the PZ5 waters today and the
PZ6 waters tonight. With a strengthening of the California
coastal trough tonight the inner PZ6 waters could see marginal
gales tonight. With the increasing winds seas of 12 to 18 ft are
expected across PZ5 today and PZ6 tonight. 

With evaluation of available 00z and 06z guidance along with 12z
NAM and hi res models see no reason to make changes at this 
time.


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PREVIOUS DISCUSSION...

High pressure will remain to the west of the region as a trough 
along the California coast persists in the short term. High 
pressure will then move southeast and be just west of the 
southern waters allowing few troughs to move east across the far 
northern waters in the extended period. Latest NCEP weather map 
still has low pressure 1010 MB inland over Northwest Washington 
state with an associated cold front stretching southwest across 
the Oregon waters. High pressure 1042 MB centered near 42N145W 
continues to extend its ridge southeast and still lies just west 
of the southern waters. Pressure gradient is relaxed across most 
of the waters and maximum winds are just below gale force over 
the far northern waters. 
 
In the upper levels at 500 MB, high pressure ridge is depicted 
along the 150W longitude while a trough with some energy is 
depicted inland. In the short term, the upper level ridge shifts 
east as it weakens and keeps most of the energy inland and this 
scenario continues into the extended period. At the surface, the 
global models GFS/CMC/UKMETHR/ECMWFHR have initialized well the 
synoptic surface observations. In the short term, models agree 
well on keeping high pressure to the west of the region most of 
the forecast period except toward the end when models have minor 
differences on low pressure that will pass over the northern 
waters. Otherwise, models are in a good general agreement on most
of the synoptic features and so will just stay with GFS for 
winds. 

.SEAS...they are still modest across the region and they range 
between 7 and 10 ft with a peak at 12 ft over the northwest 
portion of the Washington outer waters. NWW3 fits fairly well the
observed seas pattern and has been quite consistent in previous 
runs. ECMWFWAVE models also agree well with NWW3 on initially 
building seas over the northern waters and the spread southward 
into the central waters. Will just stay with NWW3 for seas. 

.EXTRATROPICAL STORM SURGE GUIDANCE...No significant surge is
expected through the forecast period.



.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
     None.

.PZ6 California Waters...
.PZZ825...Inner Waters from Point Arena to Pigeon Point...
     Gale Thursday.
.PZZ830...Inner Waters from Pigeon Point to Point Piedras Blancas...
     Gale Thursday.

$$

.Forecaster Krekeler/Musonda. Ocean Prediction Center.