DISCUSSION
Visible satellite imagery showed an area of stratus locked onto portions of the coast this afternoon. The depth of the marine layer appeared to be shallow based the rate of inland clearing and KACV profiler; no more than 1500 feet. Marine layer will most likely deepen tonight. Stratus clouds will probably cover much of the coast for the remainder of the weekend, though some afternoon clearing will certainly be possible a few miles away from the shoreline. Thicker stratus should also yield some patches of light misty drizzle, though confidence is not high there will any measurable amounts.

Temperatures in the interior will begin to "cool" below normal on Saturday with highs mostly in the 80s for the warmest valleys.
Most of Trinity county is forecast to remain in the 90's. Trough aloft with below normal 850mb temperatures will remain over the area for the remainder of the weekend and early next week. Also, a 500mb vort max will move across the area this afternoon and evening, however showers and thunderstorms are not expected due to very limited moisture and low available buoyant energy.

A deeper push of moist air associated with a decaying front and transient 500mb shortwave trough may bring some measurable precip (most likely drizzle) to the North Coast region early next week, specifically Monday night or Tue. RAW and uncalibrated ensemble probability for a tenth or more in 24 hours from the ECMWF ENS is 10-30% for Del Norte and far northern Humboldt. Some light measurable precip, most likely drizzle, appears possible (10-20% chance) even though NBM 6 hourly probabilities are silent (10% or less). Granted July is the driest month of the year on average and odds for 0.10 or more are not good with strong downstream ridging dominating. Ensemble means indicate a building 500mb ridge and above normal 850mb temperatures for the latter portion of next week. NBM probabilities for 100F or more increase to 50% or more for the typically hot interior valley locations in the interior late next week. Thus, after a break from the heat this weekend and early next week, it does appear likely that summer heat will return late next week. DB

AVIATION
Stratus has clung to the immediate coast today, driving IFR to LIFR ceilings at KCEC and KACV. Brief clearing is possible at the terminals lat this afternoon, although confidence is low as to whether or not this will actually occur at the terminals, and if it does, should only be for a few hours at most. Stratus rebuilds this evening and overnight tonight. VFR is forecast to continue for the interior through the TAF period. TDJ

MARINE
Northerlies are forecast to slowly weaken over the next few days as an upper low moves in from the SW. This will weaken the land-sea pressure gradient over the next couple of days causing winds and seas to calm down significantly. This wind shut down is currently forecasted to hold steady through the weekend into early next week, then the usual thermal trof pattern returns by mid week, generating northerlies of 10 to 15 kts. TDJ

FIRE WEATHER
Elevated to locally critical fire weather conditions due to gusty diurnally driven winds and very low RH's from 10-20% are expected through this afternoon and evening, primarily across Lake, Trinity and interior Mendocino counties. Overnight RH recoveries have been generally good to moderate, except for some exposed ridges of Mendocino and Lake Counties. A deeper marine is forecast to develop tonight and persist through this weekend as a trough aloft develops over the area. Humidities are expected to increase as temperatures decrease below average this weekend.
Afternoon winds are also forecast to be lighter this weekend.
Also, a mid level vort max will progress over the area this evening and generate slight instability into Saturday afternoon.
Some cumulus will build, however deep layer moisture and buoyant energy appears insufficient to warrant thunderstorms. A slow and moderate warming trend is expected mid next week with 100F degree heat most likely returning late next week. Chance for wetting rain, based on the NBM, is near zero for the next 7 days. DB

EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 4 AM PDT Saturday for PZZ450-455.

Small Craft Advisory until 10 AM PDT Saturday for PZZ470- 475.