, Issued at 1038 AM PDT Tue Apr 7 2026 (This afternoon through Wednesday)
The weather is mostly quiet in the short term. The marine layer deepened to 2,200 feet according to the 12Z sounding. That was enough to bring stratus to the coast and bay adjacent valleys. Those clouds are now clearing, and the cooler humid air will retreat back to the immediate coast this afternoon. Temperatures today will climb into the 70s across the interior, while the coast is stuck in the low to mid 60s. A building short wave ridge will cause a subtle pattern shift through Wednesday. The most obvious impact will be some compression of the marine layer under the higher pressure. This will cause less extensive stratus coverage Wednesday morning compared to what we saw this morning. Otherwise conditions will be very similar to today with a gentle NW breeze, comfortable temperatures, and mostly clear skies in the afternoon.
..issued at 1038 AM PDT Tue Apr 7 2026 (Wednesday night through next Monday)
The pattern starts to change on Thursday. A mature, vertically stacked, cut-off low pressure system over the Eastern Pacific will slowly drift East towards the coast through the day. The first indications of this system will be increasing high clouds and a wind shift from NW to SW. The North Bay may get some light prefrontal rain in the afternoon or evening, and it's possible that an outer rain band could bring a lightning strike or two, but for most it will be a nice day. As the low continues to drift towards the coast, rain will become more widespread Friday morning and continue, off- and- on, through the day. The biggest question of the forecast is thunderstorm chances. Cut-off lows making landfall have surprised us in the past, so it's certainly worth a deep investigation as we get closer to the event. Since there is no obvious steering mechanism, it's hard to pin down what path these cut-off lows will take. That's important as the maximum lift, wind shear, and vorticity will all line up right near the low pressure center. The timing also plays a role, with maximum instability during the warmest temperatures in the afternoon.
The thunderstorm chances are revitalized Friday as a reinforcing trough digs down from the Gulf of Alaska. Whether we get storms or not remains in question, but an associated cold front will more than likely bring additional rain to the region. Right now the afternoon looks like the wettest period, but that could still change. All told we expect to get somewhere between 0.25-0.75" across the valleys, and up to 1.5" in the coastal mountains. From a rainfall perspective, that puts this event firmly in the beneficial category, with no flooding impacts expected. The only caveat is if thunderstorms or strong showers do develop, the storm motion will likely be relatively slow, so any associated downpours could cause localized flooding, especially in urban areas. A drying trend will probably start on Sunday, but the ensemble clusters disagree on the pattern next week. There's currently a 60% chance for a warm dry ridge, and a 40% chance for a cool, wet trough.
(06z TAFS) Issued at 957 PM PDT Tue Apr 7 2026
Gentle to moderate onshore pattern wind flow will continue to diminish through the evening hours. MVFR stratus is developing at the immediate coast and should eventually cover the coastal regions and parts of the East Bay near OAK, but a compressed marine layer should allow for less inland development than last night, particularly in the North Bay interior valleys. Stratus should retreat to the immediate coast on Wednesday morning with moderate onshore flow resuming in the afternoon. Expecting more stratus coverage to develop Wednesday night as an incoming system promotes the growth of the marine layer.
Vicinity of SFO, Moderate westerly winds continue for a couple more hours with winds becoming light overnight. Moderate confidence that the terminal remains VFR overnight, although some low scattered clouds could intrude into the terminal area. Confidence for stratus impacts is slightly higher at OAK. Any stratus that develops in the vicinity will dissipate through Wednesday morning, with the west- northwest winds returning in the afternoon, with a moderate confidence for stratus returning in the evening hours into Thursday morning.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Light winds overnight through Wednesday morning. MVFR-IFR stratus has developed in patches near MRY and will expand across the terminals through the night, with impacts continuing through Wednesday morning. Breezy northwest winds resume in the afternoon, with MVFR-IFR stratus returning late Wednesday evening.
(tonight through next Monday) Issued at 957 PM PDT Tue Apr 7 2026
A gentle to moderate northwest breeze and slight to moderate seas prevail through the night. Winds will remain moderate while gradually shifting to the southwest from Wednesday through Thursday ahead of a low pressure system. This system will will bring disturbed weather with possible thunderstorms on Friday through Sunday. Winds will increase to a strong NW breeze by Sunday as subtropical high pressure builds over the Eastern Pacific.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Wednesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
