A dry cold front moved through the region in early June bringing locally gusty west to northwest winds. Winds at lower elevations were gusting to 45 mph with gusts near 60 mph east of Livermore for the Altamont and Patterson Passes as well as gusts over 50 mph in downtown San Francisco.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MTR wrote it up.
A dry cold front moved through the region in early June bringing locally gusty west to northwest winds. Winds at lower elevations were gusting to 45 mph with gusts near 60 mph east of Livermore for the Altamont and Patterson Passes as well as gusts over 50 mph in downtown San Francisco. Higher elevation areas showed wind gusts in the 50s and 60s with 66 mph observed in the Marin County Hills.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Francisco Bay Area, CA wrote its last area forecast discussion before the first event at Jun 7, 10:15 AM PST, 1 hour 36 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1115 AM PDT Mon Jun 7 2021
.SYNOPSIS...Locally strong and gusty west to northwest winds are
expected Monday afternoon and evening, especially near the coast,
and through gaps and passes. Temperatures will remain well below
seasonal averages through midweek before warming slightly late in
the week.
&&
.DISCUSSION...as of 08:23 AM PDT Monday...A dry cold front is set
to move through the region today bringing breezy to locally gusty
winds along the coast and in the hills. Observations currently
show onshore winds gusting from about 25 to 35 mph thus far this
morning. Still expecting winds to pick up this afternoon through
the evening with gusts around 45 mph (up to 55 mph in the hills
and coastal gaps) possible. Therefore, the Wind Advisory remains
in effect from 12 PM to 8 PM. A broader upper trough over the
region will keep temperatures below normal through mid week with
some slight warming towards the end of the week. Forecast remains
on track, for additional details please see previous discussion.
&&
.PREV DISCUSSION...as of 03:16 AM PDT Monday...Breezy to locally
gusty winds are forecast across the region today with seasonably
cool temperatures. The strongest winds are likely to occur along
the coast and in the higher elevations of the North and East Bay.
In these areas, expect west to northwest winds of 20 to 30 mph
with the potential for gust of 45 mph (up to 55 mph in the
peaks/ridges and locations such as Altamont and Patterson passes).
With this, a Wind Advisory remains in effect for the
aforementioned locations from 12 PM to 8 PM. Elsewhere, breezy
onshore winds will be likely with temperatures in the upper 50s to
mid 60s near the coast to upper 60s to mid 70s inland. These
conditions are due to a deepening mid/upper level trough over the
Pacific Northwest.
As the trough digs southward along the West Coast through midweek,
look for additional cooling Tuesday and Wednesday with daytime
temperatures only warming into the lower 70s for the warmest
interior spots. Meanwhile, upper 50s to mid 60s will be common near
the coast. These values are generally 5 (coast) to 15 (interior)
degrees below seasonal averages. While breezy onshore winds will
likely persist through midweek, they are forecast to gradually
weaken beyond Monday. Given the cool air mass aloft, overnight lows
will drop into lower 50s near the coast to 40s inland. A few of the
coldest interior spots may even dip into the upper 30s through
midweek. Additionally, look for only patchy clouds near the coast
and in the hills each night/morning as the colder air mass aloft
maintains a well mixed marine layer. Meanwhile, mostly sunny
conditions are anticipated each afternoon.
As the trough exits to our east on Thursday, slight warming will be
possible. However, still expecting temperatures to remain below
average through much of this week. Yet another mid/upper level
trough is forecast to impact the West Coast on Friday. With this,
look for these unseasonably cool conditions to continue with low end
potential for light precipitation over the North Bay from Friday
into Saturday based off of the latest ensembles. This said,
widespread beneficial rainfall is not anticipated across the region
at this time.
&&
.AVIATION...as of 11:13 AM PDT Monday...For the 18z TAFs. VFR.
With the exception of a few lingering marine stratus over the San
Mateo Coastal Ranges and the Monterey Bay, have cleared out
quickly this morning. Do have some high-based clouds streaming in
to the southern terminals a low to our south moves into SoCal.
Have added FEW and SCT 250 at several of the terminals to account
for their trajectory through Central California this afternoon but
will remain elevated. The most prevalent weather for the 21-03Z
timeframe will be the gusty winds across the region. Winds between
15-20 kts with gusts up to 30kts will be possible at most of the
terminals while SFO will once again go over 34 kts as the low
pressure clips the region. These winds will primarily come in from
the NW and will gradually weaken after 4Z as the low steers the
strongest winds out of the Bay Area and Central Coast. LLWS will
be observed through the overnight at some of the inland North Bay
terminals, while MVFR cigs will return to the vicinity of SFO and
the Monterey Bay tonight and into tomorrow morning.
Vicinity of KSFO...VFR. Sustained westerly winds 20-25 kt with
gusts approaching 30 kt. Winds will continue to accelerate this
afternoon as the onshore flow from the low exits the San Bruno
Gap. Airport Weather Warning will be in effect from 22Z to 4Z when
the strongest winds (>34kts) are expected. These winds will
gradually subside after 4Z but will remain breezy through tonight
(5-15kts sustained) with MVFR cigs developing along the Bay
Shoreline through the early morning.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR/MVFR. Onshore winds will pick up
again this afternoon, approaching 15-20 kts with gusts up to 25kts
along the immediate coastal terminals and the northern Salinas
Valley. These winds will subside after 4Z as the strongest low-
level winds associated with the low exit the Central Coast. Will
see a return to MVFR cigs after 7Z as the air mass stratifies once
more. These cigs will then carry us into the end of the TAF
period.
&&
.MARINE...as of 10:58 AM PDT Monday...Moderate to gusty northwest
winds will continue today across the waters and bays. Gale force
gusts are possible along the Big Sur coast south of Point Sur
through this evening. These winds will generate steep to very
steep waves resulting in hazardous conditions, particularly for
smaller vessels. Winds will diminish this evening and tomorrow,
though locally breezy conditions will persist near coastal jet
regions. The sea state remains predominately wind driven with
northwest waves 8 to 10 seconds along with a weaker longer period
southerly swell.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...Wind Advisory...*CAZ006-505-507-509>511-516-528-530*
SCA...Mry Bay
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...SF Bay from 12 PM
&&
PUBLIC FORECAST: AS/RGass
AVIATION: Diaz
MARINE: AS
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www.youtube.com/nwsbayareaThe national radar mosaic for the moment the first event began.
8 strong wind. Local standard time, as filed.
San Francisco CWOP station downtown measured wind gusts 45 to 50 mph with a peak gust of 52 mph.
Byron Airport ASOS reported wind gusts between 45 and 50 mph with a peak gust of 52 mph.
Mesonet (PG&E) station at Patterson Pass reported wind gusts between 50 and 60 mph with a peak gust of 62 mph.
Mesonet station (PG&E) on Snake Road reported wind gusts between 45 and 50 mph.
Big Rock RAWS station measured wind gusts between 50 and 60 mph with a peak gust of 66 mph.
Altamont RAWS station measured gusts in excess of 50 mph with a peak gust of 60 mph.
Mesonet (PG&E) station at BFI Office reported gust of 45 mph.
San Francisco CWOP station down town measured gusts 45 to 50 mph with a peak gust of 55 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, June 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 961395, 961409, 961411, 961396, 961400, 961415, 961402, 961394.