textproduct: Eureka

SYNOPSIS

Scattered showers are expected again today with a slight chance for thunderstorms, mainly in the afternoon. Cool temperatures and a mix of sun and clouds are expected Monday and Tuesday. Rain is expected Wednesday, mainly north of Mendocino county. Near freezing or freezing temperatures are expected late in the week with more rain possible over the weekend.

DISCUSSION

The upper level low is moving onshore this morning and continuing to bring showers and a few thunderstorms to the area. Snow levels are around 3,500 to 4000 feet with some local areas of snow down to 3,000 feet. Generally accumulations look to only be a few inches of slushy snow below 5,000 feet with larger amounts at higher elevations. This afternoon with the daytime heating and the upper level low moving overhead the models are showing a 100 to 200 j/kg of CAPE and this may be enough to bring some more thunderstorms to the inland areas. This will depend on how quickly the low moves out of the area and there is still some uncertainty on that. Snow levels are also expected to rise this afternoon with daytime heating and as the low moves out. As the low moves overhead and then out of the area winds are expected to remain lighter than yesterday.

Sunday night into Monday with the low moving out is is expected to start drying out. However, now some of the models are showing a shortwave moving down from the north and this may bring some more light rain or drizzle on Monday. Very little rainfall is expected, generally less than a tenth of an inch. However, this will likely bring enough clouds to keep temperatures in the northern valleys above freezing. Farther south skies are expected to remain more clear in Mendocino and Lake counties, although some fog may form in the valleys due to the recent rain. This could allow some frost to form and a frost advisory may be needed. Monday afternoon temperatures will generally stay in the 50s with some low 60s possible in southern Mendocino and Lake counties. Monday night into Tuesday is expected to remain dry. Frost is possible in more of the area, but there still may be some clouds and valley around, especially in the north. Tuesday afternoon temperatures may finally warm into the 60s in many of the valleys, although the coast will likely remain in the 50s.

The next weather system is expected to bring more rain Tuesday night into Wednesday. Rainfall amounts continue to increase, although probabilities drop off quickly in Mendocino and Lake counties. The Del Norte mountains have around a 50 percent chance of seeing 1 inch, however the mountains of Humboldt county only have around a 10 percent chance of seeing over an inch. Humboldt and Trinity counties are expected to see around a quarter to a half inch of rain. Northern Mendocino county is expected to see less than quarter of an inch with only a trace to a tenth of an inch farther south. Snow levels are mainly expected to be around 5,000 feet.

Thursday through early Saturday mainly dry weather is expected and afternoon temperatures will warm into the 60s and 70s once again. It looks like the valleys will finally dry out enough to allow temperatures to cool, especially Thursday morning. Overnight lows are expected to be near or below freezing. There may even be frost along the coast.

Next weekend there is the potential for another round of rain. Currently it looks like the rain will start to spread across the area Saturday night and continue on Sunday. MKK

AVIATION...(06Z TAFs)

Swaths of moderate to heavy rain over the CWA Saturday late afternoon into the evening brought periods of LIFR and reduced visibility. Intensity has waned with post frontal winds light and variable as of 05z. VFR/MVFR conditions for mostly all terminals in the CWA are expected through the TAF period with cloud cover dropping off after 07z. Cyclonic flow continues as the CCW motion, centered off of Cape Mendo, lumbers northward up the coastline. Ceilings around 5000 feet or more could come down to around 2500 feet by Sunday morning sunrise hours, MVFR conditions with light rain with sporadic infrequency expected. Chances for rain drop off by the late afternoon Sunday for the coastal terminals with a return overnight into early Monday morning. /EYS

MARINE

West to northwest winds will develop early Sunday. In addition there is expected to be a west-northwest swell around 5-7 feet at 9-10 seconds and some additional small swells through the day on Sunday.

Monday, northerly winds returns as high pressure starts to build into the area. This will promote moderate to fresh northerly breezes across the waters Monday through Tuesday, with the strongest winds south of Cape Mendocino. Wednesday, a brief wind shift to the south is expected over the northern waters as a frontal system moves through, followed by strengthening northerly winds Wednesday night through Friday as the pressure gradient tightens. There is a potential (75-95% chance) of gale force gusts late next week. /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... Winter Weather Advisory until 11 PM PDT Sunday for CAZ107.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until midnight PDT tonight for PZZ450- 455-470-475.