, Issued at 1247 PM PDT Wed Mar 18 2026 (This evening through Thursday)
The strong mid/upper level high pressure, that has resulted in several daily and monthly records the past two days, is currently over southern California and the Desert Southwest. As forecasted, the 500 mb height has strengthened to 594 dam with 850 mb temperatures around 23 degrees C. As such, temperatures this afternoon will warm into the upper 70s along the immediate coastline and into the mid 80s elsewhere closer to the coast. Elsewhere, just inland away from the coast and in the interior, temperatures will rage from the upper 80s to lower 90s and potentially the mid to upper 90s the the warmest interior spots. Some locations along the Sonoma and Marin county coastline remain in the 50s as of early this afternoon as low stratus and a shallow marine layer impacts that region.
Tonight into Thursday morning, expecting the coldest interior locations to cool into the upper 40s (mainly in the North Bay) with low to upper 50s in other valley locations. In the higher elevations across the region, we are only expecting mid 60s to lower 70s.
Thursday, we are expecting a degree or two of warming across the board. Please see the CLIMATE section below for additional details on potential record breaking heat.
..issued at 121 AM PDT Wed Mar 18 2026 (Thursday through Tuesday)
Rinse and repeat through Friday. Expect record breaking heat each afternoon as the ridge of high pressure stalls over the desert SW. Confidence is increasing that the heat wave will start to break on Saturday. Our latest forecast has temperatures dropping around 10 degrees on Saturday, and another 5 on Sunday. That would bring us back into the 70s for most inland areas and 60s along the coast to start next week. By the way, that's still 5-15 degrees above normal for this time of year. As the ridge breaks down there is good chance for stronger winds this weekend, which will bring some additional relief to the hot temperatures, but also brings some enhanced fire weather conditions for fine dead fuels. The next chance for any rain is around the end of the month or early April, but the ensemble members diverge spectacularly by that point, and it's just as likely that another dry heatwave moves in.
(18z TAFS) Issued at 1003 AM PDT Wed Mar 18 2026
Quiet weather continues with high pressure holding and mainly offshore winds being observed this morning. Diurnally driven onshore winds are expected for areas near the coast or around the Bay later this afternoon and evening and will become offshore or light and variable overnight. VFR conditions will prevail, though there could be some pockets of haze.
Vicinity of SFO, No major changes, light and variable winds, will become onshore this afternoon and evening. Winds may peak at KSFO around 10-15kt after 23Z. Wind weaken late in the evening, with light and variable winds expected overnight and into Thursday morning.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Quiet weather with offshore flow continuing this morning. Winds will gradually become onshore by the afternoon, with winds becoming weakly offshore or variable by the evening and overnight hours. VFR conditions continue.
(today through Monday) Issued at 411 AM PDT Wed Mar 18 2026
Moderate northwest breezes persist across the outer waters, with gentle breezes over the inner waters. Strengthening northwest winds and hazardous seas will likely return to the coastal waters late this week and weekend.
Ca, Heat Advisory until 8 PM PDT Friday for CAZ006-502>506-508>510- 512>518-528>530.
PZ, None.
