, Issued at 1212 PM PDT Tue Oct 6 2026 (This evening through Wednesday night)
Patches of fog and stratus linger at the immediate coast, associated with a shallow marine layer that sits around 500 feet deep. The rest of the region remains clear as large scale ridging results in sinking air, thus suppressing cloud formation processes. The ridging is also helping to compress the marine layer, so don't expect any overnight stratus outside of the immediate coast and favored areas adjacent to it, including the Petaluma Gap, the Golden Gate, and the coastal plain around Monterey Bay. On the flip side, for higher elevation areas above around 1000 feet, don't expect that much relief at night. The marine layer inversion has set up right along those areas, resulting in a thermal belting effect where overnight lows remain in the upper 60s to middle 70s, limiting the ability of the body to recover from the heat of the day. As a final note, as the ridge has set up right over our area, local pressure gradients are relatively low, and the onshore flow this afternoon has likewise been neutered.
Over the last couple of days, the default model blend has been running warmer than the observed temperatures across much of the region. On a broad scale, this is relatively minor (around 3 degrees warmer in the forecast across the inland valleys) so not a significant deviation to correct for. At the immediate coast, temperatures are significantly cooler than the model blend output would otherwise suggest. For example, downtown San Francisco reported a high of 71 yesterday compared to a forecast high of 80. Based off that assessment, I have lowered the high temperatures for today and Wednesday at the immediate coastal regions by around 5 degrees, into the middle 60s to lower 70s. This might still be an overshoot in some patches of the coast where the stratus continues to linger well into the afternoon. Elsewhere, high temperatures remain in the 80s to the lower 90s near the Bays, while the interior valleys should expect highs in the middle 90s to the triple digits (near 105 in the warmest spots of interior Monterey County).
A Heat Advisory remains in effect for the interior regions through the end of Thursday, excluding the coastal strip and the northern Salinas Valley, as widespread Moderate HeatRisk blankets the interior, corresponding to a moderate risk of heat-related illnesses for sensitive populations, including children, the elderly, pregnant women, people with chronic illnesses, and people who work or live outdoors without access to adequate cooling or hydration. In addition, many of the higher elevations are seeing Major HeatRisk, corresponding to a high risk for heat-related illnesses for anyone without hydration or cooling. Follow these tips to avoid heat exhaustion and heatstroke:
* Stay hydrated and drink plenty of fluids. * Wear lightweight, light-colored clothing. * Reduce time spent outdoors or stay in the shade. * Never leave people or pets unattended in vehicles. * Use sunscreen if going to the coast or the pool.
Minor coastal flooding is expected at the Bayshore locations along the San Pablo Bay through the next few days as up to 0.9 ft of thermal expansion surge significantly impacts the tidal level. At the San Francisco tidal gauge, high tide is expected to be 0.6 ft above normal (6.48 ft MLLW) at 8:58 PM Tuesday 10/6 and 0.6 ft above normal (6.44 ft MLLW) at 10:19 AM Wednesday 10/7. Confidence in these specific values is moderate and the high tide yesterday evening ran to 0.8 ft above normal (6.64 ft MLLW) representing a surge of around 1.0 feet.
..issued at 1212 PM PDT Tue Oct 6 2026 (Thursday through next Monday)
Hot and dry conditions continue through Thursday with the Heat Advisory for the inland locations expiring at 10 PM that night. The first hints of a pattern change arrive on Friday, when an upper level trough forming over British Columbia and the Pacific Northwest, a decaying husk of an upper level low coming in from the Central Pacific, and a weakening Hurricane Rachel (expected to be a Tropical Storm by Friday) will interact to flatten the upper level ridge and bring troughing across the West Coast for the upcoming weekend. As a side note, with the breakdown of the ridge on Friday, confidence in the High temperatures will drop closer to, or slightly below, the seasonal averages by the weekend, with highs in the 70s across the inland valleys and the 60s at the Pacific coast and near the Bays. Ensemble model cluster analysis is coming around to some sort of trough across the region for the weekend, and continues to hold on to chances for something resembling an inside slider pattern towards the end of the weekend into the early part of next week, although confidence is not high. As the trough deepens, various clusters show the trough axis developing somewhere from central Oregon and Northern California to the Great Basin. Many of the scenarios support some form of northerly flow over the Bay Area and Central Coast, but the exact orientation of the low will determine whether the flow retains a more westerly component or pushes more from due north or the northeast.
Minor coastal flooding continues along the bayshore San Pablo Bay on Thursday with high tide at San Francisco expected to be 0.8 ft above normal (6.68 ft MLLW) at 10:51 AM Thursday 10/8. With higher astronomical tides expected Friday into the weekend, a Coastal Flood Advisory may need to be issued for bayshore locations along the San Francisco and Monterey Bays closer to that time. In addition, southerly swell from Rachel will increase the risk of rip currents and sneaker waves later this week into the weekend as long period swell of 15 to 18 seconds arrives.
(18z TAFS) Issued at 1042 AM PDT Tue Oct 6 2026
After some LIFR conditions early this morning impacting Monterey Bay Region and HAF, conditions have improved. Expecting mostly VFR today all terminals with IFR/LIFR for HAF due to lingering marine layer. High pressure remains overhead compressing the marine layer again tonight. Shallow moist layer will inch inland leading to higher conf for IFR to LIFR for Monterey Bay Region and HAF. Airport mins are poss for MRY/SNS. Conf was less than 15-20% for other terminals therefore didn't include any low clouds/fog.
Vicinity of SFO, VFR through the period. NE flow into the afternoon less than 10 kts then onshore for afternoon/evening rush. Likely see a NE push again Wednesday AM.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR through this evening, but as noted above expect shallow CIGs/FG to return. Higher conf on impacts to SNS, but conf high enough to mention for MRY as well.
(today through Sunday) Issued at 939 AM PDT Tue Oct 6 2026
High pressure off the Pacific Northwest Coast and low pressure near Southern California will maintain gentle to moderate northerly breezes through Thursday. Northerly breezes will then increase strong to very strong Friday into Saturday, bringing widespread hazardous conditions for small craft. Frequent gale force gusts are likely across the northern waters during this time. Moderate seas will prevail through Thursday, building to become rough to very rough Friday into Saturday.
Ca, Heat Advisory until 10 PM PDT Thursday for CAZ503-504-506-508- 510-512>518.
Coastal Flood Advisory until 1 PM PDT Thursday for CAZ506.
PZ, None.
