San Francisco Bay South of the Bay Bridge Marine Forecast
|Today...W Winds 5 To 10 Kt, Increasing To 10 To 20 Kt With Gusts Up To 25 Kt This Afternoon.|
|Wed...W Winds 15 To 20 Kt With Gusts Up To 25 Kt.|
|Wed Night...W Winds 10 To 15 Kt With Gusts Up To 25 Kt.|
|Thu...W Winds 10 To 20 Kt With Gusts Up To 30 Kt.|
|Thu Night...W Winds 15 To 20 Kt With Gusts Up To 25 Kt.|
|Fri...W Winds 15 To 20 Kt With Gusts Up To 25 Kt.|
|Fri Night...W Winds 5 To 10 Kt.|
|Sat...W Winds 10 To 15 Kt.|
|Sun...W Winds 10 To 15 Kt.|
| Area Forecast Discussion|
National Weather Service San Francisco Bay Area
1057am PDT Wednesday July 6 2022
Without a well defined marine layer, a mix of low and mid level clouds continue today. Morning coastal drizzle may be possible in areas with lower clouds. A gradual warming and drying trend begins by midweek, however, below normal temperatures persist today through Friday for the afternoon highs. By Saturday, the region warms more becoming near to slightly above normal conditions through Monday.
As of 07:50am PDT Wednesday...Reports of light rain this morning for the SF Peninsula as well as portions of San Mateo and Marin counties have prompted an update to the forecast. Probability of precipitation (PoPs) for the next few hours have been increased to 15-20% for southern Marin county down to the Monterey Bay near the coast to account for this morning's light rain/drizzle. Sites at the SF Peninsula have reported 0.01 inches and folks are having to use their windshield wipers on the commute this morning. Higher elevation sites have reported anywhere from 0.03 to 0.10 inches due to orographic lift enhancing precipitation efficiency.
As of 04:07am PDT Wednesday...We've got another morning of mixed clouds. Looking at the Fort Ord and Bodega Bay profilers, we don't see a well defined marine layer which is allowing low and mid level clouds to move farther inland as opposed to a defined and compressed marine layer that limits the inland intrusion of coastal stratus. If you're closer to the coast and under low marine stratus, you could see a bit of drizzle again this morning.
Once again, not expecting any major temperature swings for this afternoon's highs. For the past two days, max temps have generally been within 1-3 degrees of each other, if not the same, for several of our observation sites. The upper level low offshore from the Pacific NW continues to linger and with not much change in the atmospheric environment, expect similar conditions today as we've been seeing: below normal highs with mid 60s to mid 70s closer to the coast and mid 70s to mid 80s inland. We'll see breezy conditions this afternoon into evening, also similar to yesterday.
Warming, especially across the interior, will become more noticeable as we get towards the end of the week and into the weekend. The airmass aloft will gradually warm as high pressure strengthens over the desert SW. 850 mb temps will increase towards 18 to 21 degrees C Friday and Saturday along with 500 mb heigheights increasing to 588 to 594 dm. The warmest days in the near term are forecast to occur on Sunday and Monday: coastal and bay shore highs will be in the upper 60s to low 80s while inland areas range mid 80s to mid 90s...a few upper 90s in the far interior.
What should be noted with this warming trend is that we're not expecting afternoon highs to be WELL above normal. In fact, 5-8 degrees above normal is probably the most we'll see which is not as significant as the 15 to 20 degrees above normal we saw in the June heat events. Heat Risk continues to be at Low Risk for much of our CWA with some Moderate Risk mixed in for Sunday and Monday across the interior. Even the ECMWF (European Centre for Medium-Range Weather Forecasts) EFI (extreme forecast index) is only showing about 50 to 60 percent for max temp on Monday indicating it's not an extreme event.
For the extended, it looks as though our region will be in between the center of the high pressure over the desert SW and the lingering trough over Canada & the PacNW. The trough seems to dig a little southward on Tuesday which would bring slight cooling, but then the high pressure begins to dominate again. Looking ahead at the ECMWF and GFS ensembles...they both show the peak warm up for Sunday and Monday followed by that slight cooling on Tuesday with warming again for the rest of next week. However, once again, we're not yet seeing a strong heat signal as peak temps will likely stay in the 90s across the interior and not reach triple digits.
as of 10:01am PDT Wednesday...Generally light winds will prevail over the coastal waters tonight and Wednesday, aside from increases off the Santa Cruz County and Big Sur coasts during the afternoon. Somewhat breezier conditions will then develop generally, while winds increase more substantially in jets off the aforementioned coastal stretches, and subsequently off the coast of Sonoma County as well. These will be accompanied by increasingly steep, short period wind-waves with seas becoming hazardous for smaller craft.
NOAA San Francisco Bay Area Office: Watches - Warnings - Advisories
Small Craft Advisory...Monterey Bay from 3pm