, Issued at 1253 PM PDT Sun Apr 5 2026 (This evening through Monday)
Another warm day is on the books for today. Temperatures are running around 15 to 20 degrees above normal across the interior and around 10 to 15 degrees above normal along the coast. Highs today will largely be in the 80s across the interior and 70s along the coastline. The pattern shifts quite notably heading into Monday as upper level ridging exits eastward and weak shortwave upper level troughing moves in. This will allow the marine layer to develop (albeit a shallow one between 1000-1500 ft) and we will see a "southerly surge" of stratus along the coast. If you live along the coast, tomorrow morning will feel very different than today due to the much cooler temperatures and low level stratus. There may even be some potential for coastal drizzle early Monday morning. Offshore winds are expected to become onshore again this afternoon/evening with onshore winds to then prevail through the remainder of the forecast. Temperatures cool much more noticeably on Monday with interior highs dropping into the low to mid 70s and coastal highs into the upper 50s to low 60s. Interior temperatures will still be running a few degrees above normal while coastal temperatures are fairly seasonal.
..issued at 1253 PM PDT Sun Apr 5 2026 (Monday night through next Saturday)
Cooler, wetter weather remains on track to arrive mid to late week as our next system arrives. Upper level ridging tries to rebuild on Tuesday, but, remains compressed due to a deep upper level low moving into the PNW. This results in Tuesday's forecast staying rather similar to Monday's with interior highs in the 70s and coastal highs in the 50s to 60s. By Wednesday, we start to see our next rainmaker on the horizon. The upper level trough over the PNW will exit eastwards into the Central United States with a second low pressure system approaching California from the west. This system has some characteristics of a cut-off low with cluster guidance starting to come into better agreement about it. The upper level low looks to move southwards parallel to California's coastline before moving inland over Baja California. This upper level low originates from the Gulf of Alaska and is bringing down a much cooler airmass. As the cooler airmass arrives, it will bring a return of more seasonal temperatures in the 60s to 70s across the entire region. Originally rain looked likely to return on Wednesday but guidance has shifted with the bulk of the rain now returning Thursday and Friday. Current guidance suggests rain showers will be fairly widespread across our CWA but they will be more showery than stratiform (uniform over a large area) in nature. Ensemble guidance has trended upwards recently in terms of how much precipitation we are expected. Overall the rain is still classified as light and beneficial but we can expected between 0.5-0.75" across the coastal mountains and Santa Clara Hills while the lower elevations see around 0.25-0.35". The highest amounts look to be farther south over the Central Coast in the Santa Cruz Mountains and the Santa Lucia Range. Locally breezy onshore winds are expected across the higher elevations and mountain gaps/passes but these are expected to stay well below Wind Advisory criteria.
As mentioned yesterday, there is a non-zero chance of thunderstorms across much of the area Thursday and Friday. The probability of thunderstorms has increased across the region with a 15-20% chance of thunderstorms on Thursday and Friday. In terms of support, low level lapse rates are decent (7-8 C/km) with several hundred joules of low level MUCAPE but low level shear is fairly negligible. Our thunderstorm chances and rain totals will largely depend on where the surface low pressure system moves inland and how progressive the upper level system is. If the surface low maintains its current path and moves into the Bay Area, thunderstorms will be more likely south of the North Bay and across the Central Coast. Comparatively, if it shifts more southerly (i.e. moving in over SLO), our thunderstorm chances would largely go away. Given the increase in forecast precipitation totals, dry lightning concerns with this system have largely abated. The majority of locations are now expected to see wetting rains (precipitation totals greater than or equal to 0.1") which alleviates the risk of fires started by lightning. All in all, there is some potential for thunderstorms with this upcoming system but confidence is not quite there yet. Make sure to stay up to date as we continue to narrow in precipitation totals and the potential for thunderstorms.
(06z TAFS) Issued at 953 PM PDT Sun Apr 5 2026
MVFR-IFR stratus is developing along the Pacific coast, spreading inland through the early morning hours on Monday. High confidence in stratus impacts at the immediate coast and the northern SF Bay terminals, moderate confidence in stratus impacts at SJC and the interior terminals. Stratus will retreat to the immediate coast through Monday morning, with onshore flow resuming in the afternoon. Stratus will return to the coastal regions Monday evening, with more inland expansion after the end of the 24-hour TAF period.
Vicinity of SFO, MVFR-IFR stratus will begin to flow through the Golden Gate in the next several hours, with moderate confidence in the exact timing of the stratus impacts, with the high resolution models suggesting that the terminal will be socked in by 10-12Z. Stratus will dissipate Monday morning around 18-20Z, with breezy west-northwest winds in the afternoon. Some stratus will flow through the Golden Gate Monday evening, but the highest confidence for impacts at SFO comes after midnight into early Tuesday morning.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Light winds continue through the night. IFR ceilings develop in the next couple of hours, with the stratus clearing through Monday morning before breezy northwest winds develop in the afternoon. High resolution models are depicting stratus returning on Monday evening around 02-03Z.
(tonight through next Saturday) Issued at 953 PM PDT Sun Apr 5 2026
Light to moderate winds persist over the coastal waters for much of next week. Locally fresh winds will briefly develop early to midweek across the coastal waters with locally stronger winds possible along the Big Sur Coast. Unsettled weather returns mid to late week, bringing light showers, a slight chance of thunderstorms, and moderate seas. Winds increase next weekend with a fresh breeze expected over the northern coastal waters.
Ca, None. PZ, Small Craft Advisory from 3 PM Monday to 3 AM PDT Tuesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
