marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 833 PM PDT Sat Oct 19 2019
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Low pressure was well inland with its associated cold front over the central CA waters. Another low pressure area was near 53n 147w with its occluded front and warm front extended se toward the southern Oregon waters. Elsewhere high pressure was centered W of central and southern CA near 33n 142w with a ridge NE into the central and northern pz6 waters and then N over the pz5 waters. Strongest winds this evening were associated with a coastal trough along the central and southern CA coast with NW 25 to 30 kt with gusts as high as 39 kt near 120w just S of Point Conception while to the N westerly Post frontal winds winds have been coming down near the WA/OR coast with sustained winds 20 kt or less as of 03z. A warm front will move NE over the WA/OR waters later tonight into sun with a cold front crossing the waters sun. For the updated forecast current grids looks good so no changes are planned with GFS guidance looking good through Tue night. ----------------------------------------------------------------- Previous discussion...
There was a 18z ascat pass over most of the WA, the western areas or and the outer northern CA offshore waters. Also there was a pass over the southern CA offshore waters. Max winds were to 30 kt over the WA and or waters postfrontal with winds to 25 kt over the southern CA waters in association with a coastal trof.
At 18z a broad area of high pressure was W of the central and southern CA waters. A weak cold front was moving S over the central CA waters. Elsewhere a coastal trof was along the central and southern CA coast. A warm front was to the W of the northern offshore waters which lifts NE across the WA/OR waters tonight into sun and is followed by a weakening cold front sun. Will have winds to 25 kt or 30 kt in advance of the front which moves quickly E over the WA/OR waters sun. The coastal trof over central and southern areas of CA persists over this area through Sun night, then gradually expands over the central and northern CA later on Mon through Thu. The GFS continues to be stronger with the pressure gradient between the coastal trof and high pressure to the W and NW of the northern and central CA waters. The 12z ECMWF is similar to earlier guidance with the UKMET continuing to be stronger with the high pressure W and NW of the northern CA waters. Will continue to have gales developing later Wed and Wed night. Models are all similar with coastal trof weakening later Wed night into Thu night. For the grids will continue to favor the GFS through most of the period. Will blend the GFS and UKMET for Wed into Thu maintaining gales for the inner N CA waters through Wed night before diminishing later on Wed night into Thu.
Seas...the 12z wavewatch and 12z ECMWF wam are in similar agreement through about 00z Wed and will use a 50/50 blend through this period. Will use the wavewatch through the rest of the period with minor edits with the seas along the central and northern CA waters Wed into Thu, then will use its output the rest of the forecast period.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... .pzz820...inner waters from point St. George to Point Arena... gale possible Wednesday into Wednesday night. .Pzz920...Outer waters from point St. George to Point Arena... gale possible Wednesday night.
.Forecaster Bancroft/Rowland. Ocean prediction center.