Marine Weather and Tide Forecast for Oakley, CA

DISCUSSION
A broad upper-level ridging centered over the Four Corner will continue to dominate the weather pattern for interior NorCAl through Sunday. Temperatures will peak today and Sunday, with widespread triple digit high temperatures across the Valley and foothills and overnight low temperatures in the mid 60s to 70s. With resultant widespread Moderate HeatRisk and areas of Major HeatRisk across interior NorCal. A Heat Advisory remains in effect through 10 PM Sunday for the Valley and foothills, as well as mountain locations north of Highway 50.

While hot and dry weather is expected to persist across the region, monsoonal moisture streaming from the SW along the western periphery of the ridge. Models suggest an increase in instability for today and Sunday, resulting in a 15% chance for afternoon thunderstorms along the Sierra crest south of Highway 50 through the weekend as well. Potential hazards with any thunderstorms that develop will be lightning, gusty winds, and possible new fire starts. Elsewhere, as the upper level pattern continues to limit onshore flow magnitude, low daytime humidity into the teens and single digits alongside limited to poor overnight humidity recovery will lead to a continuation of elevated fire weather conditions through Monday as well.

Early next week, a mid- to upper-level shortwave trough develops off the West Coast, while the ridge slowly breaks down through middle week. Onshore flow is expected to increase in response, providing a broader overnight relief and increasing humidity values. The heat is expected to gradually recede early through mid next week, with lingering Moderate HeatRisk through Wednesday.

Ensembles continue to suggest the upperl-level trough settles over the region, bringing more widespread cooling, with near to below normal temperatures and a decrease to Minor HeatRisk area wide.
Additionally, there are some signals within ensemble guidance for a subsequent surge of monsoonal moisture that may introduce mountain thunderstorm chances back to the forecast by late next week.



AVIATION

VFR conditions are expected to prevail over the next 24 hours.
Winds generally remain 12 kts or less at TAF sites. West to southwest gusts up to 20-25 kts in the Delta from 00Z through 12Z Sunday.

STO WATCHES/WARNINGS/ADVISORIES
Heat Advisory until 10 PM PDT Sunday for Burney Basin-Butte County Below 1000 ft-C. San Joaquin County including Stockton-C.
Stanislaus County including Modesto-C. Yolo/NE Solano including Woodland-Central Colusa County Incl. I-5-Central Glenn Co & Interstate 5-Central Motherlode 1000-3000 ft-E. Diablo Range Above 1000 ft-E. Shasta /S. Cascades Above 3000 ft-Eastern Colusa County-Eastern Glenn County-Glenn/Colusa Coast Range Above 3000 ft-Lassen Volcanic NP-N. Motherlode 1000-3000 ft-N.
Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft- Sac Metro/W. El Dorado/Amador County-San Joaquin County Delta- Shasta County Foothills 1000-3000 ft-Shasta Lake Area & 1-5 1000- 3000 ft-Shasta Metro-Sierra (Cal-Tuo) 3000-5000 ft-Sierra (Sierra-Placer) Above 5000 ft-Sierra (Tehama-Plumas) 1000-3000 ft-Sierra (Tehama-Plumas) Above 3000 ft-Sierra (Yuba-Placer)
3000-5000 ft-Sierra 3000-5000 ft-Southern Motherlode 1000-3000 ft-Sutter/Yuba counties below 1000 ft-Tehama Co Coast Range Above 3000 ft-Tracy Triangle Below 1000 ft-W Tehama Co Foothills 1000-3000 ft-W. Glenn/Colusa Foothills 1000-3000 ft-W. Shasta County 1000-3000 ft-W. Shasta County Above 3000 ft-W. Stanislaus County Above 1000 ft & I-5-W. Yolo County including Capay/I-505- Yolo / Solano County Hills.