San Luis Obispo and Santa Barbara Counties
The southwest is currently experiencing a high-pressure system that will continue to dominate through Thursday. This pattern is bringing hot conditions, particularly to the interior valleys and mountains.
Temperatures are expected to reach their peak on Wednesday and Thursday. Along the coast, a shallow marine layer will persist, leading to the possibility of dense fog from night until morning.
Heat Warnings and Advisories
Excessive Heat Warnings are in effect for the interior valleys and mountains, while Heat Advisories cover most coastal valleys through Thursday. The Santa Ynez Valleys and mountains have been included in these advisories due to rapidly increasing temperatures, which have already reached near 100 degrees in areas like Solvang and Santa Ynez.
The high-pressure system, peaking at an impressive height on Wednesday, is expected to start moving eastward by Friday. This will bring significant cooling, with temperatures dropping by 5-10 degrees. The cooling trend will likely end most heat advisories by Friday. Additionally, as the high pressure diminishes, winds are expected to increase, particularly in Southwest Santa Barbara County and interior areas, potentially reaching advisory levels.
Thunderstorm Threat
Today presents the highest chance for thunderstorms, especially in Ventura County. There is a slight chance (about 10%) that these storms could extend into the interior mountains of Santa Barbara County and the Cuyama Valley. Storms are expected to move northwest at less than 20 mph, though stronger storms may move westward, potentially affecting coastal foothills or valleys.
There’s a small chance (5-10%) of showers or thunderstorms west of the mountains late this evening or overnight. The likelihood of thunderstorm activity will decrease by Wednesday afternoon, becoming more confined to interior areas. Potential impacts from these storms include damaging winds, localized flooding, and cloud-to-ground lightning.
Coastal Conditions
The presence of a shallow marine layer means there is some dense fog potential through at least Thursday morning. By Friday, night-to-morning low clouds may become more common in most coastal areas, except for much of the Santa Barbara South Coast, where a moderate Sundowner wind will likely keep low clouds at bay.
Weekend Outlook
Cooling trends are expected to continue into the weekend, bringing more comfortable temperatures near normal for this time of year. Breezy northwest to onshore winds might approach advisory levels in some areas. A deepening marine layer could spread low clouds into some coastal valleys and foothills, especially if an eddy forms after a potential Sundowner wind on Friday evening. If the marine layer deepens rapidly, patchy drizzle could occur.
Looking ahead to early next week, the high-pressure ridge may start to build back from the east, but not likely to reproduce the heat of the next few days.
Stay tuned for further updates and take necessary precautions to stay cool and safe during this heatwave.
