Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
470 FXUS66 KEKA 252222 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 322 PM PDT Wed Sep 25 2024 .SYNOPSIS...Dry weather and above normal temperatures are forecast to return in the interior Friday through this weekend. Hotter weather conditions will likely arrive early next week. Coastal areas are forecast to have occasional low clouds through this weekend. && .DISCUSSION...Southern end of a weak trough moving into the Pacific NW has resulted in substantial cooling for the entire forecast area today. Not much precipitation has occurred with only a few sprinkles from elevated cells passing over Del Norte county. Surface high pressure will rebuild behind the trough tonight and Thu. Interior temperatures will recover to around seasonal averages (85-91) on Thu as 500mb heights and 850mb temps increase slightly. Deeper humid layer tonight will likely result in a rejuvenation of stratus and patchy fog along the coast and coastal river valleys. The low clouds will likely scour out with daytime heating and mixing. Deterministic and ensemble guidance indicates above normal 500mb heights and above normal 850mb temperatures returning Friday. Above normal interior temperature will most likely return Friday and remain above normal through the weekend. In fact, latest NBM guidance indicates 100F likely (70% chance) for southern Mendo (KUKI) on Friday. Widespread highs in the lower to mid 90s are probable elsewhere for the interior. Heat risk will increase to moderate levels on Friday in the interior valleys. A weak trough will probably knock temperatures down some over the weekend in the interior, but it will still remain warm and above normal. Northerlies and steady influx of cool-damp marine air will probably result in night and morning stratus for the North Coast through this weekend. NBM indicates clear skies while NAM12 BUFKIT shows favorable thermodynamic profiles for stratus generation. Ridge will amplify early next week leading to another round of hot weather in the interior valleys. Offshore flow may propel high temperatures into the lower to mid 70s along the coast Mon or Tue next week. Unlike the last offshore event, this one will lack deep layer easterlies and marine air may hinder the warming for coastal areas. For inland areas, anomalous warming is much more probable. Significant rain (a tenth of an inch) remains highly unlikely for the next 7 days. DB && .AVIATION...Diverse layers of clouds covered the whole region through the day; all these layers made difficult observing the marine stratus that blanketed the Redwood Coast. Stratus impacts on flying weather were greatest at ACV and CEC Taf sites due to mostly IFR/LIFR conditions. By 1 PM, ACV had lifted into MVFR then VFR. BINOVC is expected in the mid-late afternoon. The abundant cloud advection has been associated with a weak disturbance moving into the region. Noonday satellite imagery indicated light precip along the North Coast...no doubt mostly Virga. Inland: Ukiah reported some low clouds that pushed up along the Russian River this morning. Also, lots of low clouds moved over the Mendocino Near-Coastal Range as the marine layer deepened to about 2500 feet, but just couldn`t spill over into the UKI valley. /TA && .MARINE...Northerlies around 20-25 kt and steep wind waves around 8 ft will warrant issuance of a small craft advisory for the southern outer waters Thu and Fri. Northerlies will strengthen north of Cape Mendo on Friday with potential for gale force gusts and large steep waves over 10 feet - mostly over the outer waters. Elevated northerly winds and large steep seas over 10 ft are forecast to continue into the weekend. Highest seas are forecast outside 20NN. DB && .FIRE WEATHER...Much higher humidity and cooler temperatures have occurred today with passage of a trough into the Pac NW. Humidity will trend drier and temperatures warmer over the next couple of days with northwesterly and westerly diurnal breezes each day. Northerlies will return to the coastal ranges tonight and continue for the remainder of the week. Strong gusts over 30 mph will likely occur over exposed ridges of zone 201 (King Range) and exposed southern ridges of zone 202. Humidity will most likely remain high with these strong northerlies. Transient upper trough will most likely disrupt the warming trend over the weekend. Broad flat ridge will build early next week leading to hotter weather and very low RH`s. The building heat coupled with dry E-NE flow may yield elevated to locally critical conditions late Sunday into Monday and Tuesday. DB && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 AM Thursday to 9 AM PDT Friday 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