textproduct: Eureka

SYNOPSIS

A cold front arriving early Wed. morning will create strong southerly winds, widespread wetting rain, and mountain snow for some of the highest and coldest mountain passes. Small hail is possible as well until dawn Thursday. A warming trend is expected end of week through the weekend.

DISCUSSION

The cold front that has been the focus of the past few day's discussions is finally arriving and is able to be seen on our weather radar as of 2200 PDT. High resolution models show the first wetting rain (>0.10") arriving to NW CA by around 4am for Del Norte, 9am in Humboldt, around midday for Trinity and Mendocino, and early afternoon for Lake Counties. From these times through Thursday, rain totals will gather steadily for the North Coast with period of moderate to locally heavy rainfall. Mendocino Co., Lake Co., and the valleys of Trinity Co., will be subject to more light rain. Rain amounts will be much higher in terrain compared to lower elevations.

Other forms of precipitation will also fall besides rain from Wed. through Thurs. The highest passes on Hwy 36, 299, and 199 should experience light snow <1.00" where as Scott Mountain Pass (5450') is forecasted between 3-6" of accumulated snowfall. Due to the long term warmth from the past few weeks over the area, most of this snow is expected to melt by Wed. afternoon. However, it should be known that snow levels will bottom out Thursday morning as cold air fills in over the area. This cold air will likely freeze any melted snow for Scott Mountain Pass. A Winter Weather Advisory has been issued for Scott Mountain Pass to alert of these hazardous road conditions late Wed. through Thurs. Small hail is also possible along coastal Del Norte and Humboldt as cold air aloft enter the area. This cold air will increase atmospheric instability giving conditions that could lead to accumulating small hail under thunderstorms Wed. afternoon through Thurs. early morning.

Besides precipitation falling over the area, this front will also force strong southerly winds during its initial passing. Del Norte's coastal headlands and ridgetops all over the CWA will experience strong gusty winds. The coastal areas could see up to 40mph gusts and the ridgetops could see up to 50mph. A Wind Advisory has been issued for Del Norte Co. from Wed. morning through the early afternoon as the front passes as drastically increases gusts. The higher elevations of Humboldt & Del Norte could see gusts up to 50 mph with localized gusts up to 60mph. Coastal Del Norte could see gusts up to 45 mph. Further south, peak gusts of 30 to 40 mph are likely for much of Humboldt and western Trinity. Lake County will also be breezy, however this will mostly be in the afternoon with west winds of 30 to 40 mph possible. DS

AVIATION

Mostly VFR conditions at all TAF sites with SHRA moving across the area. Nevertheless, MVFR conditions are likely during the next few hours at all terminals due to increasing SHRA as a warm front push onshore from 01/06Z through 01/12Z. A strong cold front will approach the area from 01/12Z through 01/21Z from the NW. The primary concern for the aviators from Wed morning through Wed afternoon will be LLWS and gusty SW winds on the surfaace. A quick increase in SW winds is expected around 13Z along the coastal terminals. Gusty to strong winds from 25 to 40 kts are expected from 01/13Z to 01/22Z, with the strongest winds at KCEC. LLWS from 40 to 50 kts around 2000 feet AGL will be likely for ACV and CEC through this period. For UKI, winds are expected to be lighter with a period of gust winds up to 20 kts from 01/21Z through 02/04Z. MVFR conditions, dropping to IFR/LIFR conditions with heavy rain are expected at all taf terminals on Wednesday, followed by SHRA Wednesday night. There is a PROB30 -TSRA after 02/03Z for KCEC. /ZVS

MARINE

Winds shift to the SW and increase ahead of cold front Wednesday morning. Winds are expected to peak to strong to near-gale sustained SW winds across the northern waters, with mostly moderate to fresh breezes over the southern waters. Latest high- res models have been increasing the chance for gale force gusts across the northern waters Wednesday morning, where gusts up to 40 kts are likely. Have to hoisted a Gale Warning for the zones 450 and 470 from Wednesday morning through early Wednesday afternoon. A rapid wind shift and a robust W wind shift is then expected behind the front Wednesday afternoon.

A steep westerly swell will start building in Wednesday night, reaching 10-14 feet at 12 seconds on Thursday. Westerlies diminish Thursday morning, before shift to northerly Thursday afternoon. The northerlies increase more Friday, and localized gales are forecast south of Cape Mendocino Friday afternoon through Friday evening. Calmer conditions are forecast to begin by late Saturday. /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... Wind Advisory from 8 AM this morning to 1 PM PDT this afternoon for CAZ101-102.

Winter Weather Advisory from 8 PM this evening to 11 AM PDT Thursday for CAZ107.

NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning from 7 AM this morning to 3 PM PDT this afternoon for PZZ450.

Small Craft Advisory from 3 PM this afternoon to 11 PM PDT Thursday for PZZ450.

Small Craft Advisory from 4 PM this afternoon to 11 PM PDT Thursday for PZZ455-475.

Gale Warning from 6 AM this morning to 1 PM PDT this afternoon for PZZ470.

Small Craft Advisory from 1 PM this afternoon to 11 PM PDT Thursday for PZZ470.