textproduct: Eureka

KEY MESSAGES

* Hot temperatures will bring a moderate to major heat risk for portions of the area today and Tuesday. Moderate heat risk continues through the week.

* Overnight northeasterly winds and poor RH recovery will increase fire danger mainly in Del Norte, Humboldt and Trinity counties tonight and to a lesser extent Tuesday.

* Coastal warmup through Tuesday with offshore flow.

SYNOPSIS

Breezy northeast winds are keeping coastal areas mostly clear and will help warm temperatures above normal today. High pressure continues to build in is expected to bring hot temperatures to the inland valleys (warming to near 105). Some coastal clouds are expected to return starting Tuesday and expanding Wednesday through late in the week.

DISCUSSION

High pressure is building into the area as an upper level trough moves off to the east in the Pacific Northwest. This is expected to bring hot temperatures across the interior valleys. Some of the warmer valleys are expected to range from 105 to 110. Offshore flow is also expected to bring warm temperatures a bit closer to the coast today with highs in the 70s. Tonight lows are expected to generally drop into the low to mid 60s in the valleys, but the ridges are expected to see lows in the 70s. Tuesday the upper level ridge starts to move overhead and this is expected to bring a few subtle changes. In general this is expected to bring lighter winds. This may allow a southerly wind reversal start to bringing stratus north to the Mendocino coast. This may also bring some southerly winds to Ukiah which could keep temperatures a few degrees cooler in Mendocino county. The lighter winds may allow the coast north of Cape Mendocino to warm up with the combination of the lighter winds at the surface and the offshore flow aloft. This has the potential to bring high temperatures in the mid to upper 70s. Farther south it looks like the southerly winds may start to bring stratus northward.

Wednesday through Friday the upper level ridge very slowly moves off to the east. This will likely bring a return of stratus to much of the coast, although afternoon clearing is likely most afternoons. Hot temperatures are expected to continue with most valleys continuing to see highs around 100. Some cooling is finally expected for the weekend. MKK

AVIATION

Mostly clear skies are in place across the area this morning. A few local areas of ground fog are possible around sunrise at the coastal TAF sites, but if these occur they should be localized and shortlived. This afternoon breezy winds are expected once again, although the are expected to be lighter than on Sunday afternoon. Monday night into Tuesday morning, the offshore flow is weaker and this may allow some stratus to start to develop along the Humboldt coast. The Mendocino coast is expected to start seeing a southerly surge of stratus at some point early Tuesday morning. MKK

MARINE

The stronger winds have started to push off the coast in the waters south of Cape Mendocino. The gale warning has expired and have issued a hazardous seas warning through later this morning to highlight the lingering large seas. The gales are expected to continue in the outer waters through this evening, although there is lower confidence on how widespread the coverage will be in the southern waters.

Tonight and Tuesday the winds and seas continue to diminish as the high pressure gradually pushes the winds farther off the coast. Tuesday morning the weakening northerly winds are expected allow a southerly surge of winds and clouds or fog to move north. This may increase to around 10 to 15 kt along the Mendocino coast Tuesday afternoon. Tuesday night and Wednesday the northerly winds continue to weaken and allow some light southerly winds to spread across more of the area. These light winds and seas are generally expected to continue through Thursday morning. Thursday afternoon through Friday and into the weekend are expected to increasing northerly winds once again. There is the potential for gales again over the weekend, but confidence is low on this at this point. MKK

FIRE WEATHER

This morning northeast winds have start to increase at the higher elevations of Del norte county. Gusts of 30 to 40 mph are are possible at the ridges and possibly the northeast aligned drainages. Currently it looks like the dry air is only at the highest elevations, but this could still lower this morning. The current forecast is now showing a fairly big area of eastern Del Norte county with recoveries of only 30 to 40 percent. This will also impact the interior ridges of Humboldt, and Trinity counties to a lesser extent.

Afternoon RH will trend much lower across the interior to the low teens and likely some single digits by Monday afternoon and then remaining dry through much of the week. Afternoon west- northwesterly gusty winds can be expected each afternoon. These winds are expected to be more typical for the summer afternoons only lasting a few hours and not as strong as over the weekend.

Smoke discussion. This afternoon the HRRR smoke model is showing some smoke moving into eastern Trinity county, although this is expected to be fairly shortlived. In Del Norte county, the northeasterly winds are expected to return tonight into Tuesday, although they are not expected to be be as strong. However with the more persistent northeasterly winds aloft this may bring some smoke out to the coast. The HRRR and RRFS models both show some smoke make its way out to coastal Del Norte and then south into Humboldt county. Confidence is low on this, but it will need to be watched. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... Heat Advisory from 11 AM to 11 PM PDT Tuesday for CAZ102.

Heat Advisory from 11 AM Tuesday to 9 PM PDT Wednesday for CAZ105-106.

Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for CAZ108-116-117.

Heat Advisory from 11 AM Monday to 11 PM PDT Tuesday for CAZ110-111-113-114-118>120.

NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until 3 AM PDT Monday for PZZ450.

Hazardous Seas Warning until 9 AM PDT Monday for PZZ455.

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