Flooding and Coastal Flood in California, January 12 to 13, 2017

Name: Flooding and Coastal Flood in California, January 12 to 13, 2017
Start: 2017-01-12T05:00
End: 2017-01-13T22:00
Location: California

January 12 to 13, 2017 · NWS SGX · 6 events in 6 counties and zones

After a brief lull in activity, a second series of troughs and Pacific fronts moved through the region between the 10th and 14th of January. 25-1 inches in the deserts.

Where it happened

Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $10,000
Crop damage: None recorded
Events: 6

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.

What happened

The episode as NWS SGX wrote it up.

After a brief lull in activity, a second series of troughs and Pacific fronts moved through the region between the 10th and 14th of January. Rainfall totals ranged from 0.50-1.5 inches at the coast, to 4-6 inches along the coastal slopes, to 0.25-1 inches in the deserts. Snow levels in the mountains fell as low as 4,000 ft, with up to 2 ft of new snow on the highest peaks. Strong winds occurred along the deserts slopes, though peak gusts were limited to the 45-60 mph range. Impacts ranged from minor urban flooding reported in the coast and valleys, to chain restrictions in the mountains.

What forecasters said that day

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 12, 2:53 AM PST, 2 hours 7 minutes earlier.

Area forecast discussion, Jan 12, 2:53 AM PST, 2 hours 7 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
253 AM PST Thu Jan 12 2017

.SYNOPSIS...
A storm will move through Southern California today with lingering
showers mainly in the mountains through Friday. Snow is expected
in the mountains and a few thunderstorms are possible near the
coast. High pressure will bring dry weather this weekend with a
warming trend next week. A strong jet stream brings the next
chance of rain Wednesday.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

A low pressure trough is slowly developing and moving down the
California coast today. Clouds were thickening and showers were
increasing early this morning in Southern California. Widespread
rain will develop and push southeast during the day, then largely
move out tonight. But scattered showers will continue mainly over
mountains, deserts, and southern San Diego County through Friday
and even into Saturday. Rainfall for the entire system will range
from about a half inch at the coast, to an inch in the mountains
(with a few spots exceeding 1.5 inch), and less than 0.25 inch in
the deserts. The system will bring cold air leading to instability
and a small threat of thunderstorms this afternoon. That colder
air will help snow fall in the higher mountains and the snow
level will drop to about 5000 feet by the end of the day. On
Friday it will drop to about 4000 feet. Heavy snowfall will be
confined to the higher peaks (possibly a foot or more), but Big
Bear area should pick up around 3-6 inches. Little additional
snowfall after tonight, although light snow could stick as low as
4000 feet Friday in lingering light showers or flurries. The
full clear out is rather slow and messy because the low pressure
trough cuts off and dives south into central Baja California
Friday before moving east on Saturday. As it moves into Mexico,
the counter clockwise flow will mean the moist flow over Southern
California becomes easterly, something we call wrap around
moisture. So scattered showers will continue mainly in mountains
and deserts, but possibly even reach west of the mountains,
through early Saturday. Finally the dry northerly flow will take
hold as the trough moves east over the weekend. Expect some
northerly offshore winds in the San Bernardino foothills and
northern Inland Empire. Not much of a warmup this weekend, but
more sunshine. A brief amplification in the high pressure aloft
along the California coast takes place Monday and Tuesday. That
will bring warmer weather with temperatures close to average. The
jet stream strengthens across the northeast Pacific Ocean during
the middle of next week. The strong zonal flow drives a bunch of
moisture into California, and into Southern California Wednesday
and Thursday. That's our next chance of rain.

&&

.AVIATION...
121030Z...Coast/Valleys/Mountains...Widespread cigs 2000-3000 ft MSL
with vis 3SM at times due to rain and mist. Cigs could dip to 1000
ft MSL and vis to 1SM during the heavier showers and thunderstorms.
Thunderstorms could bring erratic winds with brief gusts to 35 kts.

In the deserts...SCT-BKN clouds abv 10000 ft through 18Z with
unrestricted vis. After 18Z, BKN cigs developing 2000-5000 ft MSL
and vis 3SM.

&&

.MARINE...
A couple weather systems moving through the region will bring
periods of rain through Friday and a slight chance of
thunderstorms this afternoon. Winds will be fresh from the
southwest to northwest with gusts around 20 kt at times.

&&

.BEACHES...
High tides will peak at 6.7-6.8 feet along the open coast around 7-9
am this morning. In addition, a 7 ft/12 second west swell will
produce surf of 3-5 ft today and bring a higher risk of minor tidal
overflow. A Beach Hazard Statement remains in effect. There will
also be a slight chance of thunderstorms at the beaches this
afternoon.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Warning from 6 AM this morning to 10 PM PST this
     evening for Riverside County Mountains-San Bernardino
     County Mountains.

     Beach Hazards Statement until 10 AM PST this morning for Orange
     County Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

PUBLIC...MM
AVIATION/MARINE/BEACHES...Brotherton

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 flood, 2 heavy snow, 1 coastal flood. Local standard time, as filed.

Heavy Snow, San Bernardino County Mountains

When: January 12, 5:00 AM PST to January 13, 10:00 PM PST
Where: San Bernardino County Mountains forecast zone
Reported by: County Official
Coordinates: 34.841, -116.178 (the zone’s center; the record gives no point)

A 24 hour snowfall of 10-18 inches was reported in Big Bear Lake, with 22 inches at the top of Big Bear resort as of 0900PST on the 13th. Other 24 hours snowfall reports from the area included 14-16 inches in Running Springs and Green Valley Lake, 15 inches in Arrorbear Lake, 10 inches at the end of Mt. Baldy Rd., and 7 inches in Forest Falls, Angelus Oaks and Blue Jay. Light snow continued after 0900PST on the 13th, but impacts and accumulations were minimal.

Coastal Flood, San Diego County Coastal Areas

When: January 12, 7:30 AM PST to 9:30 AM PST
Where: San Diego County Coastal Areas forecast zone
Reported by: Lifeguard
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

Lifeguards reported minor tidal overflow into low lying streets and parking lots in Imperial Beach and Oceanside (the Strand) with a high tide near 7 ft and 2-4 ft surf.

Heavy Snow, Riverside County Mountains

When: January 12, 12:00 PM PST to January 13, 9:00 AM PST
Where: Riverside County Mountains forecast zone
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

Spotters in Idyllwild reported 9-10 inches of snow in 21 hours, ending at 0900PST on the 13th. The majority of the snow fell between 1200 and 2200PST on the 12th. Some power outages were also reported.

Flood, Orange

When: January 12, 12:30 PM PST to 2:00 PM PST
Where: Orange County, 0.12 mi ENE of Corona Del Mar to 1.1 mi SSW of Santa Ana Hgts
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 33.601, -117.868

Minor street flooding from Newport Beach to Fountain Valley. A tree was uprooted near the Orange County Fairgrounds, likely due to a combination of saturated soil and gusty winds.

Flood, San Bernardino

When: January 12, 2:00 PM PST to 7:00 PM PST
Where: San Bernardino County, 1.02 mi E of Crown Jewell to 0.36 mi NNE of East Highlands
Cause: Heavy Rain
Reported by: Broadcast Media
Coordinates: 34.071, -117.202

Numerous reports of urban street flooding throughout the Inland Empire that produced significant impacts for the evening commute. The HOV lane along Interstate 60 was closed due to flooding.

Flood, Riverside

When: January 12, 3:00 PM PST to 7:00 PM PST
Where: Riverside County, 0.45 mi N of El Cerrito to 0.79 mi NNW of Norco
Cause: Heavy Rain
Reported by: Broadcast Media
Coordinates: 33.836, -117.521

Numerous reports of urban street flooding throughout the Inland Empire that produced significant impacts for the evening commute.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.
Coastal Flood: Flooding of coastal land by the sea, from storm surge, onshore wind or high tides.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2017 Every state in 2017 This day in weather history Warnings in California, January 2017

Sources

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: 675854, 676356, 675856, 675851, 675849, 676357.