textproduct: Eureka

SYNOPSIS

Dry weather and above average inland temperatures will persist into next week. A weakening front will bring a quick chance for rainfall and a period of increased southerly winds. Otherwise, dry and warm weather will persist, with periods of breezy northerly winds.

DISCUSSION

With high pressure in control, above average warmth continues for the interior, particularly south through Mendocino and Lake counties. A front will push into the Pacific Northwest early next week, with a trailing portion clipping Northern California Tuesday. Precipitable water values will be anomalously high (200% above normal), but the front will likely struggle to maintain strength as it descends south against the southern ridge Tuesday through Wednesday. With high associated IVT values, a brief period of moderate rainfall will be possible for Del Norte County, and possibly into northern Humboldt. NBM still holds a large spread in ensemble totals (the high end and less likely scenario is 0.6 to 0.9 inch for Del Norte County). Little to no precipitation is expected south of Cape Mendocino.

Southerly winds at 925 mb (near 2000 ft) will increase with the front Tuesday. This may bring a period of breezy conditions to some of the North Coast and interior ridges. An associated warm front and downsloping winds will drive coastal temperatures warmer Tuesday ahead of the precipitation

A strong Pacific high will quickly form Wednesday behind the frontal system, driving into the Pacific Northwest and Northern California Thursday. This will strengthen the pressure gradient and northerly winds, which will turn quite breezy Wednesday and Thursday. NBM holds a 60 to 70% chance for wind gusts over 30 mph Wednesday through Thursday for much of the coast, and a 60 to 70% chance for gusts over 35 mph for the Mendocino coast. The next hint of a pattern change toward wetter weather does not arrive until near the end of the month.

AVIATION

North Coast stratus has evaporated away from terminals today giving way to VFR conditions. Northerly winds will return during the daylight hours with the possibility of gusts up to 15- 20kts for coastally influenced areas. Tonight, models show agreement of stratus returning to the North Coast (>80% via HREF & LAMP models). The spread of cloud coverage will most likely begin in the Eel River Delta and Humboldt Bay area before spreading north to KACV and possibly KCEC by the early morning. High resolution models are split as to whether conditions will dip into LIFR, so the forecast remains optimistic at IFR conditions through dawn. Yet, periods of LIFR are possible late into the morning. Ceilings are forecast to clear again by 18Z (+/- 1hr) or so on Monday.

Inland areas can expect VFR conditions with breezy, terrain-driven afternoon winds mixing down from the ridgetops near terminals before another calm, clear night.

MARINE

The thermal trof that forced yesterdays gale force winds seems to have weakened enough to create sub-gale winds sooner than forecasted. The Gale Warning for the coastal waters has been cancelled as a result. However, gusts of 20-25kts are still being recorded by buoy observations at this time. Although the winds are weaker, they are still capable of creating a steep, dangerous sea states for mariners. This has lead to issuance of Small Craft Advisories for the inner coastal waters and Hazardous Seas Warnings for the outer coastal waters through this evening.

Conditions will begin to subside and calm going into this coming work week. Weak northerlies and decaying short period seas expected Monday. A passing cold front will disrupt to pressure gradient even more giving gentle to moderate breezes over the waters through Tuesday. This frontal system will also produce a small, shorter period NW swell and rain. Marine conditions deteriorate again come Wednesday afternoon as strong northerly winds return in the wake of this frontal system. There is high probability (>70% via NBM) of gale force gusts associated with these winds in the outer waters from late Wednesday through Friday early morning. Expected hazardous conditions for this time involving sustained winds up to 35kts and gusts up to 45kts. Come Saturday, winds relax to moderate northwesterly breezes with relatively calm seas.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 11 AM PDT Monday for PZZ450.

Small Craft Advisory until 11 PM PDT this evening for PZZ455.

Hazardous Seas Warning until 5 AM PDT Monday for PZZ470.

Hazardous Seas Warning until 11 PM PDT this evening for PZZ475.