textproduct: Eureka

SYNOPSIS

Dry weather continues through Saturday. Unseasonably warm afternoons and chilly mornings are likely through Thursday. Rain and high elevation snow likely returns Sunday.

DISCUSSION

Another warm afternoon is expected both today and Thursday. While temperatures may get close to daily records, it's looking like it will be just short across the area. However, even coastal areas could see upper 60s or even low 70s. Kneeland, with sustained offshore flow, could reach 80 degrees. Overnight low temperatures are forecast to be similar tonight with another chilly morning with lows in the 20s and 30s in the lower elevations. High temperatures will be similar Thursday with 60s and 70s expected across the area.

Agreement is growing on the ridging pattern ending Friday and deep, elongated trough moving through the area. Increased cloud cover and more moderated temperatures with a deep marine layer are the main impacts, at first, Friday and most of Saturday. Rain arrives sometime between Saturday night or Sunday morning. Generally, rainfall amounts are likely to be minor, but precipitation rates could briefly be moderate to locally heavy. NBM is showing around a 30 to 50% chance for over an inch of rain from Sunday morning to Tuesday morning. Higher elevations in Humboldt and Del Norte have over an 70% chance for 1 inch, and around a 30% probability for 2 inches. There is still around a 20 to 30% chance that southern Mendocino and Lake sees no precipitation. Low end precipitation amounts are around 0.25 to 0.50 inches in Del Norte, Humboldt, and Trinity Counties with less than a tenth south of Cape Mendocino. High end amounts around around 1 to 2 inches north of Cape Mendocino and a half inch to an inch south of Cape Mendocino. Winds do not currently look to be very impactful, with only a 10 to 20% chance for southerly wind gusts greater than 40 mph. Though there are higher probabilities for winds gusts greater than 30 mph, especially in wind prone areas. Snow levels are also likely to remain above 6,000 ft until Sunday night, though could drop to 3,000 to 4,000 ft Monday morning, bringing light snow to the highest passes on Highway 3 and Highway 36.

Uncertainty grows going into early to mid next week. Some ensemble members are showing a break in precipitation, while others are showing continued pulses of precipitation. What is more certain is deep troughing will bring much colder temperatures, and if there is more precipitation, more lower elevation snow. The colder scenarios have snow levels as low as 3,000 ft. Uncertainty is very high with low end precipitation amounts of 0 and high end amounts of 1 to 2 inches. Stay tuned. JB

AVIATION

VFR conditions will prevail at the TAF sites through this TAF period as high pressure remains locked over the West Coast. Offshore flow will aid in keeping marine stratus out of coastal terminals. Patchy interior valley fog is expected in the morning hours on Thursday, but this fog should remain away from UKI. Winds will remain light throughout the period. /RPA

MARINE

Winds will remain light and the sea state will be dominated by mid-period swells through Friday with high pressure locked over the West Coast. The next larger swell will build into the waters Thursday into Friday, peaking between 10 and 12 feet at 15 to 16 seconds. Southerly winds will begin to increase Saturday ahead of an approaching front but will likely remain below small craft criteria. /RPA

BEACH HAZARDS

A large swell is forecast to build into the coastal waters Thursday into Friday. Guidance is indicating the swell could peak at near 12 feet at 15 to 16 seconds during the day Friday. This would result in breakers of 14 to 17 feet. Swells of this magnitude are well below our high surf advisory criteria; however the locally developed sneaker wave risk calculator is indicating a moderate risk of sneaker waves as these swells impact the coast Friday. Beachgoers should stay far back from the surf on Friday and possibly into the weekend as additional swells impact the coast.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Beach Hazards Statement from Thursday evening through Friday evening for CAZ101-103-104-109.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 9 PM Thursday to 3 AM PST Saturday for PZZ450-455-470-475.

Small Craft Advisory from 9 PM this evening to 10 AM PST Thursday for PZZ470.