Marine Weather and Tide Forecast for Ukiah, CA

UPDATE
Temperatures haven't fallen as much as expected across the interior valley locations. This is due to two factors: 1)
greater cloud cover than anticipated and 2) the atmosphere did not de-couple and wind has been persistent. Thus, frost is no longer expected and the frost advisories have been cancelled.



PREV DISCUSSION
/issued 1252 AM PDT Sat Jun 21 2025/

KEY MESSAGES:

- Elevated to locally critical fire weather conditions through Saturday evening for Lake, eastern Mendocino and eastern Trinity Counties due to low RH's and stronger northerly winds.

- Much cooler Saturday in the interior, followed by a warming and drying trend early to mid next week.

- Light rain in Del Norte and northern Humbodlt could linger into Saturday.

DISCUSSION...Radar returns show isolated showers, which have become few overnight into Saturday and are expected to diminish in frequency by Saturday evening. Concerns for elevated to locally critical fire weather conditions are less than the previous 24 hours with RH values improving slightly. Timing for the components do not align but are enhanced at opposing hours. Winds may not line up exactly with low RH's for 8 hours or more for a red flag warning. Winds will lessen some, but remain gusty with 70-80% chance for gusts of 30 mph over the ridges Saturday afternoon and evening.

An additional burst of light and isolated shower activity is possible Saturday with wraparound moisture on the backside of the trough. Clearing skies and lessening winds in the valleys will allow for temperatures to drop to chilly levels in the interior under this colder and drier airmass. A Frost Advisory has been hoisted for some colder interior valleys. Areas where cloud cover lingers and winds stay up will not likely reach frost criteria.

A warming trend is forecast early to mid next week with highs in the lower to mid 90's by Wed for the interior valleys. Also of note is the possibility (currently 5% chance or less) for thunderstorms over the interior mountains Monday afternoon as troughing and additional shortwave energy remains over the region. Moisture looks very limited at this time, but there is variability in model scenarios.

AVIATION...06Z TAF: A cold front will continue through the region during this TAF period. Winds will remain elevated for inland terminals aloft with gusty NW surface winds. Along the Humbodlt and Del Norte coast, winds will be lighter and possible MVFR/IFR conditions are expected into Saturday morning due to rain showers migrating over terminal spaces. Along the Mendocino coast, winds will be stronger with NW gusts up to 25kts, scattered cloud coverage, and no rain expected.

Forecast confidence is high with inland terminals having breezier than normal winds. Winds into Saturday will remain elevated due to synoptic forcing instead of the usually diurnal heating. Along the coast Del Norte and northern Humboldt coast, isolated rain showers will continue east and taper off into early Saturday morning.

MARINE...As the low pressure system moves through the Pacific NW region, northerly winds have calmed. However, northerlies will increase again through Saturday afternoon and into Sunday as the low moves inland. Gentle to moderate breezes are expected early Saturday before increasing again in the southern waters. Winds are forecast to be strongest off the coast of Fort Bragg with near gale to gale force gusts Saturday afternoon. Small craft conditions are expected in the southern outer waters, with more widespread gale conditions in the southern inner waters with steep wind waves and gusty winds up to 40kts possible in areas closer to the Mendocino coast. Breezy north winds are expected to persist through this coming work week.

FIRE WEATHER...A low level northerly speed max (925mb) will likely develop over the Sacramento valley and clip the eastern peripheries of Mendocino and Lake Counties Saturday. Lower overnight humidity and gusty N-NE winds are likely over the higher terrain of Lake and eastern Mendocino (fire weather zones 264 and 277). Once again we may be flirting with locally critical fire weather conditions Saturday, lasting into the evening hours. Our neighboring NWS office in Sacramento has a Red Flag Warning out for cured grassy fuels for elevations below 1000 feet. Otherwise, daytime minimum humidities are forecast to trend drier over the latter portion of the weekend (Sunday) into early next week as temperatures increase each day and winds greatly ease.

Also of note is the possibility for thunderstorms over the interior mountains through the end of the weekend and early next week as shortwave energy remains. There is considerable model variability. At this point, there is no compelling reason to deviate from the National Blend of Model thunderstorm probability (NBM) and chances currently look less than 5%.

EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Gale Warning from 3 PM this afternoon to 11 PM PDT this evening for PZZ455.

Small Craft Advisory from 3 PM this afternoon to 3 PM PDT Sunday for PZZ475.