Marine Weather and Tide Forecast for Philo, CA

DISCUSSION
High pressure continues to bring clear skies and dry conditions across the area this afternoon. Tonight a shortwave moves by to the north. This will weaken the pressure gradient diminishing the winds, but otherwise there isn't much of an impact expected. The offshore flow could limit the coastal clouds late tonight and in the morning, but confidence is low on this. Wednesday afternoon winds will be lighter than today across the area. High temperatures are expected to start their cooling trend. Also on Wednesday over southeastern Trinity county and northeast Mendocino counties there is slight chance for a shower or possible a thunderstorm in the afternoon. Mid level lapse rates around 7c/km and there is around 200 j/kg of surface cape. Any showers that do form are expected to quickly move east and out of the area. Wednesday night more widespread coastal clouds are expected as the flow becomes more onshore. There is the potential for additional showers or possible a thunderstorm on Thursday as well. Lapse rates are slightly weaker, but instability is still around 200 j/kg of surface CAPE. Both days the flow is out of the west or southwest and not a particularly favorable pattern for thunderstorms.

Friday more widespread showers are expected as the trough becomes more of a closed low and moves overhead. The cloud cover is expected to limit surface heating and curb the potential for any thunderstorms. Highs are only expected to be in the 50s in most areas. Much of the area has a 40 to 60 percent chance of seeing more than a tenth of an inch of rain, but only the mountains of Humboldt and Del Norte counties have close to a 50 percent probability of exceeding a half inch. Saturday the upper level low is moving out of the area and few lingering showers are possible.
Saturday night the moisture around is expected to limit the potential for frost, but temperatures will likely drop into the 30s in the interior valleys. Highs on Saturday are expected to be in the 50s again with slowly clearing skies. Saturday night is likely going to be the coldest night with lows in the colder areas of the interior dropping into the low to mid 30s. Sunday skies are expected to finally clear fully, but highs are only expected to be in the 60s. MKK

AVIATION
Mainly VFR conditions at all TAF terminals this afternoon, but reduced visibility in haze is possible due to sea spray. Breezy NNW winds at 15-25 kts and gusts from 20 to around 30 kts along the coastal terminals into this evening, with the strongest winds at KCEC. Winds will gradually ease after 23/02Z, however breezy conditions will prevail at CEC through at least 23/10Z. Stratus is expected to redevelop in the vicinity of Humboldt Bay, as well as extend along the Eel River late tonight.
Southerly winds nearshore may bring back IFR ceilings into ACV late tonight into Wednesday morning. There is a chance of 20-30% for ceilings below 1000 feet by early Wednesday morning at KACV.

MARINE
Gales continue across the waters near the capes and beyond 10 miles. This is also creating steep waves of 10 to 15 feet. Tonight the winds are expected to start to diminish. The gale warnings end at 3pm Wednesday and this looks on track. The steep short period waves are expected to propagate into the inner waters and a hazardous seas warning is in place for the northern inner waters that are expected to to see the biggest waves closer to the coast. This ends at 9am Wednesday, but these may diminish sooner than expected.

Wednesday night and Thursday the winds are expected to continue to slowly diminish. These are expected to the be the lightest late Thursday night and Friday morning as a weather system moves by to the north. There will likely be a short time where they are southerly although the models are struggling to resolve the exact timing on this. Friday night and into the weekend it looks like northerly winds will return. At this point it doesn't look like the winds will be gale force, but this may change as it comes into range of the high resolution models. MKK

EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Hazardous Seas Warning until 9 AM PDT Wednesday for PZZ450.

Small Craft Advisory until 3 PM PDT Wednesday for PZZ455.

Gale Warning until 3 PM PDT Wednesday for PZZ470-475.