textproduct: Eureka

SYNOPSIS

Gusty north winds will begin to ease off overnight. Clear and dry conditions will remain through the week with a warming trend through Thursday.

KEY MESSAGES

-Strong north winds will continue overnight but weaken for most of the week with only moderate north winds close to shore.

-Generally clear skies and dry conditions even along shore through the week.

-Conditions will warm through Thursday with highs in the interior peaking near 90.

DISCUSSION

Strong north winds have peaked today. High pressure forming over the eastern pacific contrasting with a passing trough inland has formed a sharp pressure gradient parallel to shore. Gusts near 40 mph have persisted all day near shore and across exposed areas of the interior. Such wind gusts will subside near shore later tonight but will persist through early Monday around the rim of the Sacramento Valley, especially in Lake County. Otherwise strong mixing has kept skies clear though temperatures moderate, mostly in the 70s across the interior. Wind overnight will continue to preclude any frost formation.

High pressure will already begin to weaken but move more onshore Monday and through the week. This will lead to much weaker north winds with some moderate gusts to 20 mph still pushing in right along shore in the afternoon. Interior winds will transition to a more terrain controlled regime. Conditions will remain very dry with warming temperatures through the week. Highs will most likely top out around 90 for the interior on Thursday. This will constitute only a minor HeatRisk for this time of year. Hotter temperatures will help reform a marine inversion. Any stratus and fog, however, will most likely be very shallow and mix out quickly during the day.

Compared to previous runs, most ensemble members continue to show a weak trough in the far extended forecast, but have it delayed until after next week. Rather most models show high pressure slowly weakening, allow temperature to drop, through next weekend. A trough early next week could bring some light showers or thunderstorms, but the vast majority of models (80%) currently remain dry. /JHW

AVIATION

Prevailing VFR conditions are expected at all terminals during the next 48 hours. Breezy surface NW winds around 15-25 kts with gusts 25-35 kts through this evening, diminishing to 5-15 kts after 18/05Z. However, breezy conditions is expected to persist at CEC through at least 18/11Z. Low level wind shear (LLWS) around 30- 35 kts at 1000-2000 feet is expected for KUKI between 5Z and 11Z with light to gentle winds at the surface. North-northeast winds are expected to develop this evening and increase into Monday over the interior exposed ridges. This will yield clear skies across NW California tonight and Monday. /ZVS

MARINE

Gale force gusts around 34-45 kts expected across all zones, with the strongest winds downwind of Cape Mendocino. Steep to very steep, hazardous seas will continue to build with the increasing winds, peaking to 11-17 feet this afetrnoon and early evening. Tonight, the pressure gradient relax slightly and the strongest winds moves farther off the coast as the high pressure builds in. However, conditions will remain hazardous across the waters for much of the workweek with strong to gale force gusts north winds and steep to very steep seas. Gale force winds and very steep seas are forecast to persists across the outer waters through Friday. /ZVS

FIRE WEATHER

Strong north winds have peaked today with widespread gusts near 40 mph over high terrain across the interior and near shore. Humidity has dropped significantly with minimum RH of 15 to 20 percent for the driest interior locations. Winds will continue overnight, especially around the rim of the Sacramento Valley and in Lake County. Winds will weaken by Monday evening and transition to more gentle terrain wind through the week. Conditions will remain very dry with high temperatures increasing near 90 for the interior by Thursday.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until 3 AM PDT Monday for PZZ450-455.

Gale Warning until 3 AM PDT Wednesday for PZZ470-475.