North Pacific Marine Weather Discussion
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AGPN40 KWNM 192128 CCA MIMPAC Marine Weather Discussion for N Pacific Ocean...CORRECTED NWS Ocean Prediction Center Washington DC 228 PM PDT Sun May 19 2019 .FORECAST DISCUSSION...Major features/winds/seas/significant .weather for the North Pacific N of 30N and E of 150W. Low pressure was near the N California coast in vicinity of Point Arena at 18Z and should move SE and inland while continuing to weaken and dissipate. Strongest winds associated with the low pressure were to 25 or 30 kt. Buoy 46059 most recent observation had 20 kt with gusts to 25 kt with seas to 16 ft. Max seas associated with the low pressure were up to 17 or 18 ft. Another weaker low pressure was along the outer WA waters and should move NW and pass N of the area this afternoon. There was a ASCAT pass at about 17Z over small area of the offshore waters with coverage over much of the southern CA waters and a small portion of the inner central CA waters. The strongest winds were to 25 kt over the outer waters. In the short term will favor the GFS through 00Z Tue with grids. Another low pressure system was W of the WA/OR waters and tracks into the outer WA/OR waters late Mon afternoon. Model guidance shows winds increasing in advance of the associated cold front as it approaches the coastline late Mon afternoon. Plan to stay with winds to 30 kt for now. Yesterdays event with the front as it approached the OR coast was a bit stronger than guidance indicated a day or so before. Models track the low pressure SE over the inner OR waters, and then S along the OR and northern CA coast and then dissipates Tue night. For this event will rely primarily on the 12Z ECMWF and will have gales over the SW quadrant of the low. For Tue night into Wed there are some differences on the strength of the pressure gradient between High pressure W of the waters and inland areas. Plan to use the UKMET/ECMWF and blend with the GFS which is stronger than other guidance with gales over the inner central CA waters later on Wed. A coastal trof develops near Vancouver island late Wed and Wed night. Am not confident with regards to potential for gales over the inner WA waters, although this will need to be watched also later with the GFS stronger with the high pressure to the W of this region by Fri into Fri night. The pressure gradient between the high pressure and inland areas of CA diminishes Thu and Thu night as the surface high pressure ridge retrogrades further W and stalls Fri and Fri night. For wave height grids will use a 50/50 blend of the WWIII and ECMWF wam through 00Z Tue, then will favor the ECMWF wam with adjustments to lower the seas for 00Z Tue through 12Z Tue, then will stay close to the ECMWF wam the remainder of forecast. .EXTRATROPICAL STORM SURGE GUIDANCE...With potentially strong low pressure approaching the next several days, please continue to monitor the coastal NWS offices for storm surge information. The latest surge guidance appears reasonable through Tuesday with the GFS winds and surge models appearing reasonable. .WARNINGS...Preliminary. .PZ5 Washington/Oregon Waters... .PZZ815...Inner Waters from Florence OR to Point St. George... Gale Tuesday. .PZZ915...Outer Waters from Florence OR to Point St. George... Gale Monday night into Tuesday. .PZ6 California Waters... .PZZ820...Inner Waters from Point St. George to Point Arena... Gale Possible Wednesday. .PZZ920...Outer Waters from Point St. George to Point Arena... Gale Monday night into Tuesday. Gale Possible Tuesday night. .PZZ825...Inner Waters from Point Arena to Pigeon Point... Gale Possible Wednesday into Wednesday night. .PZZ830...Inner Waters from Pigeon Point to Point Piedras Blancas... Gale Possible Wednesday night. $$ .Forecaster Rowland. Ocean Prediction Center.