Excessive heat, red flag warnings in Bay Area, NorCal extended into the weekend
The relentless heat wave baking the Bay Area and Northern California, originally expected to peak on Tuesday of this week, will last into the weekend, forecasters said Friday, along with critical fire weather conditions in some areas.
The National Weather Service said an Excessive Heat Warning was extended to 11 p.m. Saturday for the Marin and Sonoma Coastal Range, North Bay Interior Mountains, San Francisco Bay shoreline, East Bay Hills and interior valleys, Santa Clara Valley, and eastern Santa Clara Hills. Temperatures are expected to exceed 90 degrees and many spots will surpass triple digits.
The warning also applied to the Santa Cruz Mountains, interior Monterey County, San Benito County, Santa Lucia Mountains, Southern Salinas Valley, and much of the Central Coast.
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A Red Flag Warning was also in effect for many of the same areas through 9 a.m. because of low humidity and fuels that have been drying out for days in the heat wave, combined with expected periods of offshore winds with gusts up to 20-25 mph, the Weather Service said. The winds were expected to peak late Friday and early Saturday.
Compared with Thursday, temperatures were expected to drop a few degrees Friday before spiking again on Saturday. The Weather Service said gradual relief from the heat wave should begin Sunday although significant cooling may take several days to arrive.
The relief will be rather slow, however, and some areas may hold on to impactful heat into Monday, especially inland and southward along the Central Coast," the Weather Service said in its daily forecast summary. "There does appear some reasonable confidence in the pattern finally breaking down with a longwave trough moving in from the northwest by Tuesday."
On Thursday, San Jose was among the locations breaking records with the heat wave. The 101-degree high recorded in San Jose was the highest temperature ever recorded in the city on Oct. 3, passing the previous high of 97 in reached in 1917 and 1985. The Weather Service said it was the first time San Jose had temperatures of 100 or more for three days in a row in October.
Other records set or tied Thursday were in Monterey County where King City set a record with 103 degrees, surpassing the previous Oct. 3 high of 102 in 1980. The Salinas Municipal Airport tied its record of 99 degrees set on Oct. 3, 1985.
Also on Friday, the Bay Area Air Quality Management District said a fifth-straight Spare the Air alert would be in effect for Saturday because of the extended heat wave leading to unhealthy levels of smog in the region. The hot weather, combined with weak winds and exhaust from motor vehicles was creating elevated concentrations of smog, otherwise known as ozone, according to the air district.
Bay City News contributed to this report.