887 FXUS66 KEKA 122047 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 147 PM PDT Thu Jun 12 2025 .SYNOPSIS...Low heat risk is forecast in the interior with near to slightly below average temperatures through Sunday. Slight warming is forecast early to mid next week. Stronger coastal northerlies should clear out the stratus during the afternoons. && Key Messages: * Low heat risk in the interior with daytime high temperatures in the 80`s through Sunday. * Slight warming and low heat risk forecast to continue early to mid next week. * Gusty westerly and northwesterly breezes with low daytime humidity in the interior valleys each afternoon through Saturday. * Stronger and gustier coastal northerlies expected Friday and perhaps Saturday. && .DISCUSSION... Broad upper level trough will remain offshore over the northeast Pacific through the weekend. High temperatures in the interior will continue to trend down on Friday and then edge up some over the weekend. Most interior sites will remain in the 80`s through the weekend. Heat risk will remain low this weekend, but hot weather may still impact individuals who are extremely sensitive. Stronger afternoon and evening west-to-northwest breezes are expected for many of the interior valleys through Friday. Gusts generally from 15-20 mph are likely (60% chance or higher), though wind channeled valleys and ridges will have stronger gusts from 25-35 mph. Coastal northerlies will also increase on Friday and gusts from 35-40 mph are possible (60% chance) over the headlands; Pt St George and Cape Mendo. W-SW flow aloft with embedded shorter wavelength troughs will occasionally traverse into the Pac NW Friday-Sunday. First one is expected on Friday, followed by another one on Sunday. SW flow is dry and precip chances remain quite low, below 10% or zero. Larger scale trough passage is forecast to occur Monday. Once again precip chances remain meager. Building 500mb heights and broad flat ridging will likely result in slight interior warning Tue into Wed next week. Higher PWATs spill over the offshore ridge in westerly flow Mon-Tue next week. Chances for a few hundredths of an inch of precip increases a bit. With very little or no impacts from this minuscule amount of rain or drizzle, will not adjust any of the NBM precip probabilities. No clear signs for a major warm up either through much of next week. If anything temperatures will probably trend downward late next week as yet another trough digs southward from the Gulf of AK. && .AVIATION... 18Z TAF: Deep marine layer remains present over the northern Humboldt and Del Norte coasts this afternoon. MVFR conditions prevail at CEC with light NW flow while ACV has struggled to climb out of IFR ceilings. Gusts 10 to 15 knots possible this afternoon with potential for brief scattering - chances are better at CEC where northerly winds offshore may once again scour out a portion of the stratus shield, similar to yesterday. Similar IFR ceilings expected to redevelop north of the Cape late this evening and overnight with mist possible closer to sunrise, especially around Humboldt Bay and the Eel River Valley. HREF indicates 40 to 60% chance for <1000 foot ceilings to develop at CEC as winds continue to strengthen offshore. There is <50% chance for stratus development spilling over into the Russian River Valley at UKI. Otherwise, northerly winds will continue to increase Friday, allowing a better chance for scattered to nearly clear skies for the coastal terminals. && .MARINE... Winds will continue to gradually increase across the waters through Friday. Widespread fresh to strong northerly breezes have been observed over the last 24 hours as the coastal pressure gradient tightens. Small areas of near-gale to gale force gusts are possible downwind of Cape Mendocino and Point Saint George beginning this afternoon, becoming more likely Friday and Saturday afternoon. Winds will likely push closer to shore each afternoon and evening, driving some steep short period waves into the inner waters. Winds and seas remain be elevated through the weekend, especially in the outer waters with wave heights 8 to 10 feet at 8 to 9 seconds expected. Strong northerly winds forecast to decrease slightly and retreat to the southern waters early next week. && .FIRE WEATHER... Gusty west to northwest breezes are forecast to continue through Friday in the interior valleys. Gust magnitude will vary widely, generally peaking around 15-20 mph in the afternoons and evenings. There have been windier sites gusting to 25-35 mph, particularly in Lake, eastern Mendocino and eastern Trinity. These gusty W-NW diurnal winds along with minimum RH`s from 10-20% may yield an increased risk for small and fast spreading grass fires, particularly in Lake County. Some higher elevation windier sites extending into and above the inversion have been reporting poor RH recoveries; 15-25%. Otherwise, most lower elevations will continue to have good overnight recoveries once winds become light or calm. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PDT Saturday for PZZ455-470- 475. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png