The Bay Area is sweltering under a heat dome that's set a string of daily record temperatures and is now extending an Excessive Heat Warning for San Francisco through 11 PM Thursday. Inland portions of the Bay and Central Coast are also affected. Coastal regions, while not under the same warning, still face significant heat as advisories carry on parallel with the more severe inland warnings, according to the National Weather Service.
The NWS San Francisco office isn't taking any chances, opting to properly extend these advisories and warnings to preempt any complacency that might arise from hopes of a quick end to this heat event. Amidst this unrelenting temperature surge, the city has seen its daily heat records shattered, painting a stark reality of the new temperature norms. The "Key Points" of the NWS Area Forecast Discussion spotlight a mix of heat advisories, excessive heat warnings, and a Rest Flag Warning for interior areas due to increased fire risk.
While coastal winds turn to aid city dwellers by nightfall, granting some relief, the hills and valleys further inland cling to their heat well into the dark hours. The upper 70s to near 90 temperatures at elevation at night underscore the minimum respite from the daytime scorching. The marine layer, usually a natural cooling blanket, is squashed beneath this oppressive high-pressure system, allowing only sporadic gusts to appease the coast momentarily.
Fire danger has escalated alongside the mercury. With critically dry fuels and breezy offshore winds, conditions are primed for ignitions and swift fire spread, reminiscent of devastating fire seasons. Fire officials urge residents to practice extreme caution, have emergency plans ready, and immediately report any sign of fire. "Current 100 and 1000 hr fuels are near or slightly below avg, but trending drying Current 10 hr fuels are critically low as well," the warning reads, highlighting the gravity of the situation, as detailed by the National Weather Service.
Aside from the scorching heat and fire threat, the marine scene also feels the effects with a Small Craft Advisory flagging fresh to strong northwesterly winds. Mariners should exercise caution as wave heights reach 10 to 12 feet across northern waters. The Marine section of the forecast suggests conditions will begin to improve post-Thursday, as winds are expected to mellow out yet remain northwesterly through the weekend.
