Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
576 FXUS66 KEKA 061232 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 532 AM PDT Sat Jul 6 2024 .SYNOPSIS...Today is expected to be the hottest day for many areas in NW California. Cooling is expected to be limited in Trinity and Lake counties on Sunday while areas closer to the coast start to see some cooling. Enhanced fire weather risk continues with westerly diurnal winds, especially in trinity and Lake counties. Temperatures will ease slightly but remain above average through much of next week. && .DISCUSSION...Strong high pressure remains in place over the area this morning. High temperatures are expected to approach the all- time record high in Ukiah of 117. Currently the NBM is showing 40 percent chance of exceeding 117. Most inland areas are expected to see temperatures a few degrees warmer than Friday. The Humboldt and Del Norte coasts are expected to be hot again with highs in the mid 70s at the immediate coast. Just inland is expected to see highs in the 80s. The Mendocino coast and southern Humboldt coast have some low level fog off the coast and this may keep the immediate coast in the 60s if this doesn`t dissipate before morning. The valleys are continuing to see some relief overnight with lows dropping into the 60s. The ridges however are remaining warm with some areas remaining in the mid 80s. Sunday the high pressure starts to shift off to the east slightly. This will start to increase the northwesterly winds which is expected to push some marine air up the NW to SE oriented river valleys such as the Eel. This is expected to cool off in southern Humboldt enough to allow the heat advisory to expire this evening. It is possible this will need to be extended if conditions end up warmer than expected. This will also help to cool off the coastal areas. Most other areas will not see more than a couple degrees of cooling. Monday some additional cooling is expected, mainly in the areas influenced the marine air, but all areas will cool slightly. Tuesday through the end of the week temperatures are expected to slowly moderate, but remain above normal. Many of the valleys will continue to see highs over 100. Additional heat advisories may be needed. As the heat starts to abate a threat for thunderstorms over the interior will start to develop. Some of the ensembles are showing a shortwave trough moving up the west side of the ridge just off the coast. So far non of the thunderstorm probabilities are showing anything more than 5 percent until late in the week. Even then they only peak around 8 to 10 percent in Trinity county. Still the threat is there, sometimes the NBM probabilities fail to pick up these low probability thunderstorms. Tuesday the two of the four ensemble clusters show increasing moisture. This will need to be monitored as it gets closer. These thunderstorms would likely be fairly dry if they do occur. MKK && .AVIATION...Mostly clear skies overnight will promote low level fog development to a limited affect this morning. A shallow inversion at the coastal terminals will further enhance low level moisture along with marine stratus for near coastal regions. That said, offshore flow will hinder low level fog and stratus development as day brake develops and drier air aloft mixes down. IFR/LIFR flight categories will be short lived this morning for the previously stated reasons. MVFR/VFR will prevail this afternoon and through the evening with a return to LIFR conditions tonight at KCEC and KACV. KUKI may see gusty winds in the late afternoon with VFR flight conditions prevailing. /EYS && .MARINE...Fair seas and calm winds prevail for all area waters for the next 24 hours or so. Northwesterly winds start to build overnight with seas responding by Sunday morning in the northern outer waters as wind waves with square profiles develop. Small craft advisory conditions will begin in the northern outer waters Sunday morning with the previously mentioned square wind waves which will expand into the southern outer waters soon after. A small craft advisory has been hoisted to cover the developing conditions through the beginning of the week. /EYS && .FIRE WEATHER...Hot temperatures continue and are expected to bring RH down to 5 to 15 percent again this afternoon. The typical diurnal afternoon winds will be slightly enhanced by the hot temperatures and this will increase fire weather conditions. Red flag warnings are in place for this afternoon in the driest areas, southern Lake county and Trinity county. Tonight the valleys are expected to decouple again and see recoveries of 40 to 50 percent. The thermal belts are expected to see temperatures only drop to around 80 with RH recoveries around 20 to 30 percent. Tonight winds are expected to become light again so have ended both red flag warnings in the late evening. Sunday as the upper level ridge starts to push east areas closer to the coast are expected to start seeing a slight marine push. Winds are expected to weaken in Lake county, but may remain elevated in Trinity county. A fire weather watch remains in place. A small threat for thunderstorms remains for much of next week, but it is not high enough to put in the forecast yet. See discussion above for details. MKK && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Heat Advisory until 8 PM PDT Monday for CAZ102-112. Heat Advisory until 11 PM PDT this evening for CAZ104. Excessive Heat Warning until 7 PM PDT Monday for CAZ105-107- 108. Excessive Heat Warning until 8 PM PDT this evening for CAZ106. Red Flag Warning from 2 PM this afternoon to 10 PM PDT this evening for CAZ283. Fire Weather Watch from Sunday afternoon through Sunday evening for CAZ283. Excessive Heat Warning until 8 PM PDT Monday for CAZ110-111- 113>115. Red Flag Warning until 11 PM PDT this evening for CAZ264. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 6 AM Sunday to 9 PM PDT Monday for PZZ470-475. && $$ 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