A strong 1051 mb surface high settled over the Great Basin, resulting in strong winds through the passes and canyons of Southern California. The most widespread winds occurred on the 27th.
Every event with a place to put it; 8 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 SGX wrote it up.
A strong 1051 mb surface high settled over the Great Basin, resulting in strong winds through the passes and canyons of Southern California. The most widespread winds occurred on the 27th. The winds downed trees from the mountains to the coast, flipped big rigs and induced temporary road closures. Tree damage was likely augmented by saturated soils caused by heavy rains over the prior week.
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 Diego, CA wrote its last area forecast discussion before the first event at Jan 27, 2:27 AM PST, 3 hours 33 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
227 AM PST Fri Jan 27 2017
.SYNOPSIS...
Offshore flow will produce northeast winds that will become very
strong and widespread today. These strong offshore winds will
continue through the weekend, but will gradually weaken and
become less extensive tonight through Monday. It will be warmer
this weekend through Monday under clear skies. Onshore flow
arriving Tuesday will start a cooling trend. A trough of low
pressure will approach Thursday with a slight chance of showers.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Skies are clear this morning and the winds are blowing. A low
pressure trough dropping south through the West has produced
strong northerly flow aloft, or upper support for these winds. At
the surface a very steep pressure gradient has set up, about 16
mb from central Nevada to Southern California (that's steep, and
will get steeper). So far gusts over 50 mph have been observed
around Fremont Canyon and gusts over 35 mph are common in
foothills. These will only increase this morning and spread out
into many valleys and Orange County. Wind speeds will max out
between about 6 am and 3 pm today. Peak gusts around Rancho
Cucamonga, Fremont Canyon and the western slopes of the Cuyamaca
Mountains will top 75 mph. Gusts in the metro areas could top 45
mph in spots. Winds will pull back slightly this evening, not
quite as widespread or strong, but will continue strong through
Saturday morning more in the usual wind prone areas such as
foothills. Winds will gradually decrease over the weekend, but
Monday morning still has localized breezy winds. Temperatures will
hold steady today as that trough reinforces the cold air mass
we've had lately. After that trough drops into Mexico a fairly
robust ridge of high pressure builds into California, a little
stronger than previous model guidance had suggested. Now we're
forecasting max temps in the 70s for most lower elevations Sunday
and Monday, and we might get a spot or two hitting 80 on Monday.
Clouds will be hard to find through Monday. By Tuesday the
offshore flow finally gives up allowing the onshore flow to assume
its normal role. That will start a cooling trend Tuesday at the
coast that will extend farther inland Wednesday. A trough of low
pressure in the northeast Pacific will break down the ridge and
begin to send moisture and rain into northern and central
California. This could drop far enough south for a few showers in
Southern California Thursday, but rain chances look better Friday.
&&
.AVIATION...
270938Z...FEW clouds AOA 20000 ft msl and vis P6SM through tonight.
NE wind gusts of 50-70 kt are possible along coastal mountain slopes
and adjacent foothills, with 25-45 kt gusts possible along portions
of the coasts and valleys through 28/0300 UTC. These winds will
create SVR uddfs/llws/rotors over and S, SW and W of the mountains.
Expect strongest and most widespread winds during the 1800-28/0000
UTC. LLWS is expected for most areas when winds are not surfacing.
Confidence is high that KONT, KSBD and KSNA will be impacted with
strong surface NE surface winds (max gusts around 35 kt at KSNA, 25
kt at KSBD and as high as 60 kt at KONT), while confidence is low-to-
moderate in KSAN and KCRQ getting the strong NE surface winds (max
gusts 30 kt). Winds and associated uddfs/llws will lessen a little
after 28/0300 UTC.
&&
.MARINE...
Areas of northeast wind gusts of 25-30 kt are possible over portions
of the coastal waters today due to a strong offshore flow pattern. A
Small Craft Advisory has been issued as latest model guidance shows
the strong winds being a little more widespread than before. Winds
should be weaker on Saturday.
&&
.BEACHES...
A long period west-northwest swell from 290 degrees is expected to
peak this morning at 8 ft/19 seconds, and then lower during the
weekend. This will likely produce 5-7 ft surf today, with local sets
to 8 ft south of Del Mar. A High Surf Advisory remains in effect
through this evening. Strong rip currents are also expected through
the period, making for hazardous swimming conditions.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning until 1 PM PST Saturday for Orange County
Coastal Areas-Orange County Inland Areas-Riverside County
Mountains-San Bernardino County Mountains-San Bernardino
and Riverside County Valleys-The Inland Empire-San Diego
County Mountains-San Diego County Valleys-San Gorgonio Pass
Near Banning-Santa Ana Mountains and Foothills.
High Surf Advisory until 7 PM PST this evening for Orange County
Coastal Areas-San Diego County Coastal Areas.
Wind Advisory from 6 AM this morning to 6 PM PST this evening
for San Diego County Coastal Areas.
PZ...Small Craft Advisory until 4 AM PST Saturday for Coastal Waters
from San Mateo Point to the Mexican Border and out to 30 nm-
Waters from San Mateo point to the Mexican Border Extending
30 to 60 nm out including San Clemente Island.
&&
PUBLIC...MM
AVIATION/MARINE/BEACHES...HarrisonThe national radar mosaic for the moment the first event began.
5 high wind, 3 strong wind. Local standard time, as filed.
The mesonet station at Sill Hill reported high winds with a peak gust of 75 mph between 0610 and 0620PST.
Periods of strong Santa Ana Winds blew through the passes and canyons of the Santa Ana Mountains between 2200PST on the 26th and 1200PST on the 28th. Strongest winds surfaced between 0700 and 1000PST on the 27th with a peak gust of 88 mph at Pleasants Peak and 87 mph in Fremont Canyon.
Several periods of gusty Santa Ana winds downed a tree near Peter's Canyon Regional Park and power lines in eastern Villa Park.
Santa Ana Winds with gusts of 40-45 mph surfaced briefly on the morning of the 27th in Santa Ana and Irvine. Winds downed a large tree that block 3 lanes along Interstate 405.
Locally gusty Santa Ana Winds briefly surfaced along the coast of San Diego County, including parts of the San Diego Metro. Peak gusts were in the 30-45 mph range. Winds combined with saturated soils to down at least 3 large trees in Downtown San Diego and Mission Valley. The trees crushed 2 cars.
Periods of gusty Santa Ana winds developed between 0000PST on the 27th and 1200PST on the 28th. Strongest winds were reported in Devore with a peak gust of 71 mph between 0810 and 0910PST on the 27th. The winds downed power lines and trees in San Bernardino and Ontario. Two big rigs overturned, one near Mira Loma and another at the Interstate 10 and 15 inter-change.
The Sill Hill mesonet reported a second period of high winds between 1730PST on the 27th and 1210PST on the 28th, with numerous gusts in excess of 70 mph and a peak gust of 99 mph between 0140 and 0150PST on the 28th. Other stations in the mountains reported wind gusts in the 40-60 mph range during the same period. Several big rigs were overturned along Interstate 8 and multiple trees were blown down along Highway 79.
The mesonet station in Potrero measured a 60 mph gust between 2240 and 2230PST, and the mesonet at Dye Mtn. measured a 58 mph gust between 2240 and 2250PST. Elsewhere, peak gusts were in the 35-55 mph range between 0700PST on the 27th and 1200PST on the 28th. A couple trees were downed near Fallbrook.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, January 2017
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: 676338, 676333, 676334, 676335, 676347, 676337, 676340, 676343.