DISCUSSION
Weak ridging with nearly zonal flow persists aloft over northwest California today through early Saturday. This will keep the region dry during this period, while bringing more seasonal temperatures back to the interior of the region through the early weekend. More significant surface ridging has drifted toward the coast, strengthening the pressure gradient along coastal terrain and bringing relatively gusty northwest winds of up to 25 mph this afternoon. Higher gusts to potentially 35 mph are possible for coastal headlands, particularly around Cape Mendocino. Gusty coastal onshore winds will develop each afternoon for the next few days, but trend down in strength through Saturday.

Nearly all guidance has been well aligned for longwave troughing to persist aloft into early next week. An additional shortwave is forecast to approach the region this weekend, ushering in a chance for more precipitation. Latest guidance depicts this trough dropping down the West Coast, pivoting over Mendocino county, then moving NE toward the Great Basin. With this track, a majority of the precipitation looks to wrap around the low from the east, moving in from the Central Valley...which means that Trinity and eastern Mendocino could see more rain than the coast, should this track hold. This also increases the chances for thunderstorm development, with the best chances at the moment looking like the Trinity Alps and Trinity Horn Sunday afternoon and Monday, while model soundings depict a warm nose inversion developing for areas further south which could cap convection. Another low is forecast to move onshore on Wednesday, bringing additional rain. /JLW+TDJ



AVIATION
Coastal terminals remain VFR this afternoon as an strong surface pressure gradient develops beneath an exiting upper trough, elevating northerly winds keeping the marine layer well mixed. Gusts exceeding 25 to 35 knots are possible through the evening, with the higher end of these gusts most likely at CEC.
Elevated onshore flow with gusts 10 to 15 knots are also likely UKI.
As winds diminish after sunset, a brief period of LLWS is likely along the coast with elevated 20 to 25 knot winds still present aloft. Marine stratus will struggle to redevelop given an ill- defined and well mixed inversion. HRRR probabilities and hi-res model soundings are hitting potential for IFR visibility's and broken ceilings in the Humboldt Bay area just prior to sunrise tomorrow morning before quickly scattering out. Otherwise, strong winds offshore will continue downwind of Port Orford and Cape Mendocino, promoting relatively clear conditions at the coast.



MARINE
Strong northerly winds 20 to 25 knots are being observed this afternoon across the waters as the surface pressure gradient tightens behind an exiting upper trough. Gusts 25 to 30 knots are expected in the outer waters through Friday, with locally higher gusts to 35 knots possible in the outer waters and downwind and nearshore of Cape Mendocino. Steep responsive wind waves at 7 to 9 feet are forecast through Friday, becoming confined to the southern waters by this weekend. Long range models are beginning to outline potential for a deep trough to produce elevated winds and seas by early next week.



EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 PM PDT Friday for PZZ455-475.

Small Craft Advisory until 9 PM PDT Friday for PZZ470.