textproduct: Eureka

SYNOPSIS

Above-seasonable temperatures are expected to continue with widespread Minor HeatRisk for the interior through Tuesday. Temperatures will cool gradually starting on Wednesday and into the weekend. A weak cold front will promote a deepening marine layer and coastal drizzle. Enhanced west to northwest winds through the channeled terrain and higher terrain on Wednesday, shifting to the coast Thursday afternoon.

KEY MESSAGES

- Above-normal temperatures through Tuesday, with interior Minor HeatRisk.

- Gradual cooling trend and return of marine layer are expected starting on Wednesday and continuing into the weekend.

- Enhanced west-northwest winds through the channeled terrain and higher ridges on Wednesday, followed by breezy north-northwest winds along the coast and exposed ridges on Thursday.

DISCUSSION

High pressure continue to dominate the Pacific Northwest and Northern California, leading to dry weather and above-normal temperatures. Afternoon interior temperatures peak today with highs in the mid 80s to mid 90s, supported by abundant sunshine and light to gentle breezes. Widespread interior Minor HeatRisk, primarily affecting those who are extremely sensitive to heat and without cooling or hydration. Meanwhile, mild weather throughout the day along the coast with highs mainly in the upper 50s to mid 60s.

Tonight into Tuesday, a shallow marine layer is expected to develop along the coast with a light southerly winds nearshore charging up the low clouds and fog near the coastal areas. The high pressure begin to weaken and shift eastward on Tuesday, while a shortwave trough approaches the area. Coastal stratus are expected to lift and scattered out throughout the day on Tuesday, allowing to another sunshine day. Another day of warm to hot temperatures is forecast across the interior on Tuesday, with Minor HeatRisk. Onshore flow will push back inland the stratus early Tuesday evening. The marine layer is expected to slightly deepen Tuesday night into Wednesday. Patchy drizzle is expected to occur with a saturated layer along the North Coast late Tuesday night through Wednesday morning.

A gradual cooling trend will start on Wednesday as a cold front moves through. An enhanced west-nortwest winds is expected along the channeled terrain and exposed ridges in the wake of the front. Gusts from 25 to 35 mph are most likely, with locally up to around 40 mph possible. The combination of dry weather, warm temperatures and gusty winds will bring an elevated fire weather threat for eastern Lake County (see Fire Weather section). Other than more persistent coastal low clouds, bouts of patchy drizzle will also be likely Wednesday night through Thursday.

Thursday, a surface high pressure will builds in. This will aid in rebounding daytime temperatures across the area on Thursday. In addition, breezy north- northwest gusts of 25 to 35 mph over the coastal and exposed ridges.

The NEPAC upper-level trough and zonal flow will trend temperatures cooler Friday and into the weekend. Ensemble cluster analysis suggest the strong upper-level trough digging southward on Saturday. The WPC 500 mb cluster analysis suggest just a 25-30% chance of light rain over Del Norte and farther northern Humboldt counties on Saturday, with a 20% chance on Sunday. Elsewhere will remain with prevailing dry weather. /ZVS

AVIATION

Clear skies are in place across the area this afternoon with some northwest winds along the coast. Tonight with the weaker wind flow and local southerly flow at the coast, expect there will be a return of low clouds and fog by Tuesday morning. There is still a lot of uncertainty on the timing and height of the ceilings. The HREF shows a few hours of clearing in the afternoon, but confidence is low on that at the immediate coast. Tuesday evening any coastal areas that do clear will likely see a quick return of clouds before sunset. Inland areas are generally expected to remain clear Tuesday night, but stratus will likely make its way up the river valleys near the coast. At this point it looks like UKI will remain clear Tuesday night. MKK

MARINE

The northerly winds are expected to gradually diminish tonight, mainly near the coast. Farther offshore 15 to 20 kt winds are expected to persist. The waves remain around 7 to 10 feet and are also expected to diminish slightly. This is mainly wind driven waves with a small portion of swell as well. These winds and waves are expected to persist tonight.

Tuesday and Wednesday a weak shortwave approaches and moves through the area. This will diminish the winds through the day Tuesday, in the northern waters. These are expected to remain lower Tuesday night and early Wednesday. Wednesday afternoon high pressure builds back into the area and northerly winds quickly increase once again Wednesday night. Thursday and Friday near gale to gale force gusts are expected across the waters once again. This will need to be monitored as it gets closer. Generally the waves are expected to be steep and wind driven with no notable swells. MKK

FIRE WEATHER

Dry weather with above normal temperatures through Tuesday. A weak cold front will promote an enhanced west-northwest breezes across the channeled terrain and exposed ridges Wednesday afternoon and evening. Good to moderate RH recoveries are expected to prevail for most of the area. Farther south in Lake County, moderate low RH recoveries combine with locally gusty winds over the ridges is expected to bring locally elevated conditions in the fire weather zones 419 and 421 on Wednesday. As result, have to include a headline in the Fire Weather Forecast. Otherwise, dry weather will prevail. /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PDT this evening for PZZ450.

Small Craft Advisory until 9 AM PDT Tuesday for PZZ470.

Small Craft Advisory until 3 AM PDT Tuesday for PZZ475.