FXUS66 KEKA 301148 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 448 AM PDT Mon Sep 30 2024 .SYNOPSIS...A dry, warming trend is expected mid week, along with hot interior temperatures. Breezy northwesterly winds along the coast, ease overnight into Tuesday. Gusty offshore flow over the interior ridges will last through Tuesday. Dry and above normal temperatures are expected to persist through the forecast period. && .DISCUSSION...Marine stratus has been mostly curbed overnight, keeping skies clear and ground fog minimal as the work week begins. Ridging builds into the area as pressure heights indicate a warming trend through Tuesday with a warm deep- layer air-mass developing across the WRN CONUS. Model guidance has been consistent supporting 850 mb temperatures of 25-28C or so over much of the interior. Interior heat will build today and then peak on Tuesday. High temperatures in the hottest valleys are expected to range from 97- 110F degrees. The heat risk is forecast to be moderate over the area, but a major heat risk is expected to occur over portions of interior Mendocino and Lake counties on Tuesday and Wednesday. The heat will have impacts on some individuals sensitive to heat, especially those without effective cooling and/or adequate hydration. A Heat Advisory is now in effect from 11AM Tuesday through 11 PM PDT Wednesday for interior Mendocino and Lake counties. Meanwhile, thermal troughing will shift offshore heading into Tuesday, allowing for coastal areas to even heat up into the 70s, with adjacent coastal areas reaching the low 80's on Tuesday as the usual afternoon onshore breezes are quelled. Wednesday, the high pressure weakens and "flattens" as an upper level trough moves across the Pacific Northwest. This will promote high clouds streaming across the area. Temperatures are expected to decrease a few degrees, although will remain similar to late Tuesday across the interior valleys. Breezy to locally windy conditions are expected every day through Thursday, with overnight offshore flow. The ridge aloft will shift eastward late in the week, with an upstream upper level trough approaching the area. Cluster analysis lacks agreement with regards to timing and location of this trough. Models continues to differ with the progression of this system. && .AVIATION...Building ridge aloft coupled with offshore wind flow will result in clear skies for all forecast terminals today through tonight (12Z Mon-12Z Tue). LLWS due E-NE flow aloft will be continue to be possible over KCEC aerodrome til 19Z. Gust to 25 kts are expected to develop at KCEC - primarily after 18Z, otherwise surface wind speeds are forecast to remain around 5-10kt. DB && .MARINE...Very steep waves (11-13 feet at 8-10 seconds) are forecast to continue in the outer waters today through tonight. Gale force wind gusts to 40 kt are also expected in the outer waters today and a gale warning remains in effect. Winds may also gust to 35 kt inside 10NM downwind of Cape Mendocino and Cape Blanco, however coverage will be localized. Seas will remain steep and elevated across the inner waters today and a small craft advisory remains in effect. Northerly winds and steep waves are forecast to remain elevated Tuesday through Wednesday, and then diminish each day toward the end of the week. DB && .FIRE WEATHER...A Red Flag Warning is in effect for zones 203 and 204 through 11AM Tuesday. Low daytime humidity values from 10 to 25 percent are occurring across the interior. A headline remains for zone 264 due to elevated fire weather threats. Winds are expected to diminish this afternoon, but gusty conditions will remain over Del Norte and northeastern Humboldt into Tuesday morning. A drier airmass with an offshore flow component, will promote poor RH recovery values this morning, and poor recoveries Tuesday and Wednesday morning. Hot temperatures from 95 to 110F along with low humidity and breezy offshore flow, will promote elevated to locally critical fire weather risks for zones 283, 276, 277, and 264 through Thursday. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Red Flag Warning until 11 AM PDT Tuesday for CAZ203-204. Heat Advisory from 11 AM Tuesday to 8 PM PDT Wednesday for CAZ110-111-113>115. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT this afternoon for PZZ450. Small Craft Advisory until 9 AM PDT this morning for PZZ455. Gale Warning until 9 PM PDT this evening for PZZ470. Hazardous Seas Warning from 9 PM this evening to 3 AM PDT Tuesday for PZZ470. Gale Warning until 3 PM PDT this afternoon for PZZ475. Hazardous Seas Warning from 3 PM this afternoon to 3 AM PDT Tuesday for PZZ475. && $$ 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