Issued at 857 PM PDT Sun Aug 16 2026
Forecast remains on track this evening with no updates necessary. An increase in mid/upper level cloud cover is providing some insulation to radiative cooling, with temperatures running 5-10 degrees warmer than this time (9p PDT) Saturday evening. Also, a reminder that areas in vicinity of the Timber Fire will continue to smell smoke trapped under the overnight inversion up and down the Big Sur coastline.
, Issued at 130 PM PDT Sun Aug 16 2026 (This evening through Monday night)
Water vapor imagery continues to show an upper level trough of low pressure off the California Coast and high pressure over the Desert Southwest this afternoon. As a result, California remains situated between the two, with southwesterly flow aloft. There is quite a bit of upper level moisture over the ocean moving through this flow, so expect an increase in high clouds across the region over the next 24 to 36 hours. Meanwhile, we still have a relatively deep mariner layer lingering along the immediate coast. As a result, coastal areas are still running 2 to 3 degrees behind temperatures at this point yesterday, but inland areas are running slightly warmer, given the earlier clearing time. Either way, most locations across our region are still going to be below normal or right at normal for this time of year.
The 12z morning KOAK sounding showed the marine layer around 1800 feet deep, and given the observations this afternoon, doubt it has compressed much if any today. Therefore, expect another good push of low clouds and fog inland this evening and tonight, with similar clear times and temperatures for tomorrow. Palmer
..issued at 130 PM PDT Sun Aug 16 2026 (Tuesday through next Saturday)
The main story for this week will be the battle between the trough off our coast and the ridge to the southwest, and which one will influence our forecast the most. At this point in time, the models are suggesting that the ridge should be the dominate feature for the first part of the work week, with 850 mb temperatures climbing approximately a degree or so each day through Wednesday, before the influence of the trough takes back over for the latter part of the work week and the weekend as it is forecast to move closer to the coast.
However, this is where things get interesting. There is a lot of upper level moisture filtering northeastward in the southwesterly flow aloft. We are already seeing some thin high clouds associated with the leading edge of that moisture, but there is a large bulk of that moisture (cloud cover) that is not translucent. Therefore, even through the models are suggesting a gradual warm up across the inland areas, current thinking is that this upper level cloud cover will likely limit day time heating and provide a decent insulting blanket at night. And all of this said is not taking the marine layer influence into account. Therefore, my confidence in an actual "warm up" is not high. In fact, my gut says it may likely be dependent on the day, and how much Sun we actually see. Therefore, expect most places to remain at or below normal for the next week, with only minor day to day fluctuations possible this week and through next weekend.
Now, you may have also noted that I said this a lot of this moisture is not translucent. In fact, current clean IR band shows what is likely a convective band just south of 25 North and 130 West, so the question is will this moisture get pulled into the flow for us? Maybe, but it does not look likely. There is some hinting at higher precipitable water values upwards of an 1 inch for Thursday and Friday, but any instability with it diminishes as it gets here. Therefore, expect our predominately dry conditions to continue across the region. Palmer
(06z TAFS) Issued at 1004 PM PDT Sun Aug 16 2026
IFR-LIFR stratus is being observed at coastal terminals, but the spatial extent is unclear owing to widespread high clouds blocking satellite observation. The overnight stratus forecast is moderate confidence with the current forecast leaning towards IFR-LIFR stratus expanding across the region and the inland valleys, before stratus retreats back to the immediate coastal regions through Monday morning. May need to monitor for the stratus not developing to the previously forecast extent with high clouds preventing radiational cooling overnight. Light winds prevail into Monday morning before moderate onshore winds resume Monday afternoon.
Vicinity of SFO, VFR with high clouds at present. Moderate confidence that IFR stratus returns within the next few hours with low confidence on the exact timing, with high resolution model output showing the stratus deck right at the edge of the terminal. Stratus clears out late Monday morning with breezy onshore winds resuming in the afternoon. Stratus returns Monday evening and overnight with moderate confidence on the timing of the stratus.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, IFR-LIFR conditions persist overnight with stratus clearing at SNS late Monday morning, while confidence in a scattering of the ceilings at MRY during the afternoon and evening hours remains low to moderate. Stratus begins to expand again early Monday evening, including over SNS. Light winds persist through Monday morning before moderate onshore winds resume Monday afternoon.
(tonight through next Saturday) Issued at 857 PM PDT Sun Aug 16 2026
Northwesterly gentle to moderate breezes persist with localized fresh gusts across the inner coastal waters. Winds increase to fresh to strong breezes late Monday and remain elevated through the end of the forecast period. Seas of around 4 to 6 feet will build to 7 to 8 feet by Tuesday and Wednesday. A long period southerly swell around 14 to 16 seconds will continue to subside through the early work week.
Ca, None. PZ, None.
