Heavy snows over the prior week produced an avalanche near Mt. Baldy on January 26th that trapped 3 hikers.
Every event with a place to put it; 2 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.
Heavy snows over the prior week produced an avalanche near Mt. Baldy on January 26th that trapped 3 hikers. Two of the hikers were injured. San Bernardino County Fire rescued the hikers via helicopter and transported them for medical attention. Further south in San Diego County, lingering moisture from prior storms produced convective snow showers over the mountains. Snowfall accumulations of 1-3 inches were reported along with a closure of Interstate 8.
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 23, 3:53 AM PST, 1 hour 7 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
353 AM PST Mon Jan 23 2017
.SYNOPSIS...
A large low pressure system near the West Coast will move slowly
inland through Tuesday. Much colder air aloft will spread
southward across Southern California today. This is expected to
increase shower coverage and intensity today and bring a slight
chance of thunderstorms with small hail. Showers will gradually
decrease for tonight and Tuesday. Dry and slowly warmer for
Wednesday through Friday. For Saturday through Monday...high
pressure aloft near the West Coast and surface high pressure over
the Great Basin will bring greater warming and periods of gusty
northeast winds.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A large low pressure system near the West Coast will move slowly
inland through Tuesday. Much colder air aloft will spread
into Southern California today. 500 mb temperatures near -30 C
extend as far to the southeast as Point Conception early this
morning and will spread southeastward across Southern California
today...then remain entrenched across Southern California into
Tuesday.
Periods of showers will continue today with greatest
precipitation totals mostly near the mountains. The combination
of daytime heating and the cooling aloft will increase the
instability today. This is expected to increase shower coverage
and intensity today...especially from late this morning through
the afternoon...and bring a slight chance of thunderstorms with
small hail. Showers will gradually decrease for tonight and
Tuesday.
Guidance has trended a Little weaker with the winds for today
though stronger and gusty west winds will continue in the
mountains and deserts today. Gusty west winds in coastal and
valley areas are mostly expected to remain below advisory strength
today with strongest gusts near the coast and near stronger
showers and isolated thunderstorms.
Snow levels early this morning are near 5000 feet in the mountains
of San Bernardino County and 5500 in the mountains of San Diego
County and continuing to fall and are expected to fall to 3500 to
4000 feet for later this afternoon into this evening.
Cool weather will continue through Tuesday with high temperatures
remaining mostly in the 50s even at the lowest elevations near the
coast and in the lower deserts.
For Wednesday through Friday...dry weather is expected with a
slow warming trend with high temperatures remaining below average.
For Saturday through Monday...high pressure aloft near the West
Coast and surface high pressure over the Great Basin will bring
greater warming and periods of gusty northeast winds.
&&
.AVIATION...
231100Z...West of the mtns...BKN-OVC clouds layered from 1000-12000
ft msl will continue today, with vis mostly unrestricted except
where clouds and terrain intersect. During periods of rainfall, CIGS
could lower to 1500 ft msl or less with vis 3-5SM even at lower
elevations. A decrease in showers and some scatter out is expected
after 04Z tonight particularly vcnty ksna.
In the deserts...clouds layered 5000-15000 ft msl will prevail
today, with periods of BKN cigs 800-1500 ft msl and vis about 2SM
during rain showers this morning. Expect obscurations in higher
terrain at times.
South to southwest winds 15-20 kt gusting to 30 kt will continue
today into tonight. This will produce stg-svr up/downdrafts and LLWS
over and N, NE, and E of the mountains.
&&
.MARINE...
Strong winds with gusts approaching gale force will continue today
into tonight. Large swell and hazardous seas will continue through
most of Tuesday. A Gale Warning continues through tonight. Winds
will diminish tonight and Tuesday with seas very gradually
decreasing later Tuesday.
The storm will also bring heavy rain squalls at times through this
afternoon, with a slight chance of thunderstorms today and tonight.
Waterspouts will be possible as well. A Marine Weather Statement
contains more details.
&&
.BEACHES...
High surf will continue today through Tuesday threatening damage to
coastal structures and the beaches. Strong rip currents will add to
the big surf to make dangerous swimming conditions. A high surf
warning continues in effect and contains more details. Early morning
high tides will only be around 5 ft, so anything more serious than
minor coastal flooding is not expected from the large surf. Swell
and surf will decrease late Tuesday and Wednesday.
In addition, there will be a slight chance of thunderstorms today
and tonight.
More high surf is expected Friday as a large northwest swell with a
long period arrives.
&&
.HYDROLOGY...
Periods of showers will continue today with greatest
precipitation totals mostly near the mountains. The combination
of daytime heating and the cooling aloft will increase the
instability today. This is expected to increase shower coverage
and intensity today...especially from late this morning through
the afternoon...and bring a slight chance of thunderstorms with
small hail. Showers will gradually decrease for tonight and
Tuesday.
Through Tuesday...additional rainfall for Orange...southwestern
San Bernardino...and Riverside Counties...
Coast...........0.25 to 0.5 inch.
Valleys.........0.5 to 1 inch.
Mountains.......1 to 2 inches with local amounts to 3 inches.
Upper deserts...0.25 to 0.5 inch.
Through Tuesday...additional rainfall for San Diego County...
Coast...........0.5 to 1 inch.
Valleys.........0.75 to 1.5 inches.
Mountains.......1.5 to 2.5 inches with local amounts to 3.5 inches.
Deserts.........mostly 0.25 inch or less.
Given the convective nature of the precipitation...locally greater
amounts are possible in bands of showers...stronger showers with
heavier rainfall...and isolated thunderstorms.
Snow levels early this morning are near 5000 feet in the mountains
of San Bernardino County and 5500 in the mountains of San Diego
County and continuing to fall and are expected to fall to 3500 to
4000 feet for later this afternoon into this evening...then
fluctuate near 3000 to 3500 feet for later tonight into Tuesday.
Given saturation from recent rainfall...urban and small stream
flooding and isolated flash flooding can occur quickly with
additional heavy rainfall. A Flash Flood Watch remains in effect
into this evening...except for mountain areas above the snow
level.
Flood warnings remain in effect for the Santa Margarita River and
for the Whitewater River in the Coachella Valley. The Santa
Margarita River at Ysidora crested at 14.6 feet at 11:45 PM Sunday
evening. That is the fifth highest crest on record and the highest
crest since the highest crest on record of 20.47 feet in January
1993. The river level is continuing to fall early this morning but
remains above flood stage. The San Diego River at Fashion Valley
has remained below flood stage overnight. It reached a crest of
8.7 feet around 1:30 AM and is slowly falling. That level is
sufficient to affect some of the lower crossings.
&&
.SKYWARN...
Skywarn activation is requested today from 10 AM to 6 PM.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Flash Flood Watch through this evening for Apple and Lucerne
Valleys-Coachella Valley-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 Coastal
Areas-San Diego County Deserts-San Diego County Mountains-
San Diego County Valleys-San Gorgonio Pass Near Banning-
Santa Ana Mountains and Foothills.
Winter Storm Warning until 6 PM PST this evening for Riverside
County Mountains-San Bernardino County Mountains-San Diego
County Mountains.
Wind Advisory from 6 AM this morning to 6 PM PST this evening
for San Diego County Deserts-San Gorgonio Pass Near Banning.
Wind Advisory until 4 PM PST this afternoon for Apple and
Lucerne Valleys.
High Surf Warning until 10 PM PST Tuesday for Orange County
Coastal Areas-San Diego County Coastal Areas.
PZ...Gale Warning until 4 AM PST Tuesday 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/HYDROLOGY...17
AVIATION/MARINE/BEACHES...MMThe national radar mosaic for the moment the first event began.
1 winter weather, 1 avalanche. Local standard time, as filed.
CHP closed Interstate 8 for a short period due to a heavy burst of snow. The time of the closure was approximately 1500 to 1800 PST. Two big rigs jackknifed and subsequently crashed due to snow cover on the interstate.
An avalanche on Mt. Baldy trapped 3 hikers. Two of the hikers were injured.
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: 677705, 676331.