textproduct: Eureka

KEY MESSAGES

* Moderate to major heat risk continues through the weekend for much of the interior.

* Coastal stratus to continue for much of the North Coast.

* Increased winds and low relative humidity will elevate fire danger this weekend.

SYNOPSIS

Persistent high pressure aloft will remain through the week. Inland areas are subject to abnormally hot temperatures of through the weekend. Coastal areas will remain mostly overcast with temperatures in the lower 60s near the water.

DISCUSSION

A steady ridge of high pressure continues to impact the west this week leading to warm to VERY hot temperatures for the inland areas. Most inland valleys can expect high temperatures between 100-110degF through the work week. The coast continues to offer some relief from this heat. Offshore stratus is blanketing much of the western seaboard from the Mexican boarder up through Oregon. Temperatures will struggle to reach 65degF for coastal communities due to this compressed marine layer. However, above average SSTs will limit the likelihood of any true daytime fog.

The weather pattern will have minimal changes through the week as this high pressure is expected to remain overhead. A shortwave moving by to the north will bring slightly cooler temperatures today, although this will be shortlived. Some warming is expected Friday and Saturday. A slight change in weather is possible this weekend. Cluster and deterministic global model analysis shows this high pressure ridge beginning to evolve into a more flatter ridge through the weekend leading to potential zonal or even slight upper level troughing entering next week. If this solution materializes, it could lead to increased winds near the surface with hot and dry conditions expected to continue Saturday. These weather elements together can lead to increased critical fire weather concerns. Until then however, expect warm interior temperatures and foggy nighttime hours along the coast. Some slightly cooler temperatures will start lower the heat risk Sunday with some additional cooling next week. MKK/EYS

AVIATION

Model guidance is on the pessimistic side for the overnight flight conditions. When taking the previous overnight conditions into consideration along with similar set up, persistence and caution are wise. LIFR conditions with ceilings under 500ft are in place this morning at KCEC and KACV. With offshore stratus encroaching on the coastline and already making its way up the river valleys, Thursday morning will prove to be an LIFR situation until the late morning/early afternoon Thursday. Stable air mass and subsidence are helping sock the coastal terminals in. KUKI will have prevailing VFR conditions as the depth of moisture profile may not overcome orographic obstacles into the valley. /EYS

MARINE

One more day of gentle to moderate breezes are expected across the waters. There may a few areas of southerly winds lingering near the coast this morning, but these will mainly turn northerly this afternoon.

Friday and into the weekend, a more uniform regime of northerly winds are forecasted to return to the area. Gales are possible over the weekend into early next week with the likelihood of gusts >30kts over 80% for most of the outer waters from Saturday through most of next week. Conditions with these increased winds will likely cause for marine hazards. Plan any seafaring accordingly with this weather change happening Friday afternoon.

FIRE WEATHER

Conditions are expected to remain hot and dry through Friday. This heat wave will likely cause an increase in fire risk as the fuels dry. This weekend, the synoptic weather pattern is likely to change ever so slightly. This change will be felt by an increase in the likelihood of stronger valley winds each afternoon. The primary areas of concern are in the eastern Trinity River valley and on the eastern side of Clear Lake in Lake County. Watch for updates as forecast confidence increases on this potential weather change.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Heat Advisory until 11 PM PDT this evening for CAZ105-106.

Heat Advisory until 11 PM PDT Friday for CAZ108-116-117.

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

NORTHWEST CALIFORNIA COASTAL WATERS... None.