textproduct: Eureka

SYNOPSIS

Strong to gusty south winds early this morning through late afternoon for mostly coastal headlands and higher terrain of Del Norte and Humboldt counties. Light to moderate rain is forecast this afternoon through early evening, followed by lingering showers into Wednesday. Rain chances returns this weekend as another frontal system approaches from the west.

KEY MESSAGES

* Gusty to strong south wind gusts from 35 to 50 mph are expected through this afternoon over the coastal headlands and exposed ridges in Del Norte and Humboldt.

* Light to locally moderate rainfall is forecast this afternoon into early evening, with lingering showers into Wednesday.

DISCUSSION

A shortwave trough and associated cold front approaches rapidly the area from the west overnight, while moisture has surged across the area. Surface observations reported breezy to gusty southerly winds over the coastal headlands and exposed ridges. Resulting in greater mixing and warming for mostly the higher terrain. Strong southerly winds will be likely early this morning through through this afternoon, with gusts from 40 to 50 mph are likely over the coastal headlands and exposed ridges in Del Norte and Humboldt counties. Highest chances for gusts > 45 mph over the coastal headlands and higher terrain after 10 AM PST this morning. Peak gusts may hold off til 10 AM-1 PM PST. A wind advisory is in effect through 4 PM PST this afternoon.

A quick progressive cold front will bring light to moderate rainfall this afternoon through early evening. Rain amounts forecast generally range from 0.25 to 0.50 inch from late this morning through early Wednesday, with the most of the rain is expected between 10 AM PST this morning to 10 PM PST this evening. Lesser amounts from 0.1 to 0.3 inches for Lake County. Higher amounts of rain over 1 inch is forecast for southwest facing aspects in the King Range and Del Norte County mountains. Lingering showers are expected into Wednesday morning. Due to dry antecedent conditions and low flows on the rivers, no major impacts are expected.

High pressure is expected to return Wednesday afternoon and then dominate into Thursday. Overall dry weather is expected. Slight possibility for light upslope precip with a warm front Thu-Fri. Global ensembles and WPC guidance indicates more precip possible over the weekend as another shortwave trough heads toward Pac NW. Probabilities for 0.25 to 0.50 inches of rain in 24 hours increases to 30-50% for the northern most counties and 15-35% for the southern most and eastern most valleys of our forecast area by 4 PM Sunday. Still a great deal of variability with the amounts and timing, but overall no signs for major impacts from rain or snow at this time. /ZVS

AVIATION...(6Z TAFs)

VFR conditions are being observed over the terminals. These conditions are likely to continue at least until sunrise as south winds keep ceilings high. Winds will increase overnight, with winds aloft already starting to increase. Low level wind shear will be a threat as winds are much stronger aloft, especially around CEC and ACV. Surface gusts are likely to start mixing down shortly after sunrise, with gusts up to 35 kts possible at ACV and up to 40 kts at CEC. Winds will be lighter in Mendocino and Lake Counties, but gusts could still exceed 20 kts in the lower elevations. Light to moderate rain with MVFR ceilings will follow these winds in the afternoon and evening. Winds and rainfall will exit the area in the evening, with only a few lingering showers remaining overnight. JB

MARINE

Winds will sharply increase this morning ahead of an approaching system. Gales are forecast for most of the waters, especially north of Cape Mendocino. Steep seas of 10 to 13 ft are forecast with these winds over the outer waters. Locally higher seas of up to 15 ft are possible in the northern outer waters. Winds ease below gale force Tuesday night and short period seas will start to subside. However, a large, long period westerly swell will arrive Wednesday afternoon into Thursday, bringing combined seas of 14-16 ft. Winds remain southerly for the remainder of the week and are likely to remain breezy north of Cape Mendocino. JB/JJW

EKA WATCHES/WARNINGS/ADVISORIES

CA... Wind Advisory from 10 AM to 6 PM PST Tuesday for CAZ101.

Wind Advisory from 4 AM to 6 PM PST Tuesday for CAZ102-105- 106.

Wind Advisory until 5 PM PST Tuesday for CAZ104.

NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning from 3 AM to 3 PM PST Tuesday for PZZ450-470- 475.

Small Craft Advisory from 3 AM to 10 PM PST Tuesday for PZZ455.

Small Craft Advisory until 3 AM PST Tuesday for PZZ470-475.