California, 2024

Flooding and Strong Wind in California, December 28 to 29, 2024

December 28 to 29, 2024 · NWS EKA · 5 events in 3 counties and zones

A continued series of storms brought more rain to Northwest California late in the month. This resulted in numerous reports of landslides and flooding across the region.

Where it happened

Every event with a place to put it; 1 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

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
5

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 EKA wrote it up.

A continued series of storms brought more rain to Northwest California late in the month. This resulted in numerous reports of landslides and flooding across the region. Additionally, gusty winds resulted in more tree damage including on primary highways.

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 Eureka, CA wrote its last area forecast discussion before the first event at Dec 28, 2:18 PM PST, 5 hours 42 minutes earlier.

Area forecast discussion, Dec 28, 2:18 PM PST, 5 hours 42 minutes before
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
218 PM PST Sat Dec 28 2024

.SYNOPSIS...Occasional rain showers continue across the area this
afternoon gradually becoming heavier. Tonight a cold front is
expected to bring heavy rain and strong winds to much of the area.
Showers will continue on Sunday and possibly isolated
thunderstorms. Dry weather, colder mornings and valley fog are
expected for Monday and Tuesday. Light rain is possible in the
north again later in the week.

&&

.DISCUSSION...Westerly flow continues to bring some light rain or
drizzle to the area. This is gradually increasing through the
evening. There may be a brief break later this evening. Later
tonight a cold front is expected to move across the area. Strong
southerly winds are expected ahead of this and as it moves
through. There is plenty of support aloft with 850 mb winds of 50
to 60 kt. The strongest winds are expected to be on the Del Norte
coast. Farther south and east the strongest winds will remain
over the higher terrain and exposed coastal areas. The high wind
warning and advisories remain on track. Widespread areas of 1 to
3 inches of rain are expected with this front. Local amounts over
4 inches are expected in the higher terrain of Del Norte and
northern Humboldt counties. Light rain has started across much of
the area and this will gradually increase this afternoon and
evening. The biggest threat for flooding will be later tonight
when the cold front moves through. The flood watch may start a bit
earlier than needed, but will leave it in place. Areas farther
south and east should see a brief period of heavy rain with the
cold front very early Sunday morning, but this is not expected to
last long enough to cause significant flooding. Snow levels are
expected to remain high with the bulk of the precip associated
with the cold front.

Showers will continue behind the cold front. Snow levels are
expected to drop to 3500 to 4000 feet, but snow amounts are
generally only expected to be around 1 to 2 inches. There is the
threat of thunderstorms as these showers move onto the north
coast. The GFS and NAM both show some instability Sunday
afternoon. The best lapse rates aloft and deepest CAPE are
expected to be on the coastal areas of Humboldt and Del Norte
counties so the slight chance for thunderstorms looks appropriate.

Sunday night into Monday morning the showers are expected to
taper off and skies aloft will clear. Any areas that do clear will
likely see fog form quickly and it may be dense. Clearing skies
are expected on Monday high pressure builds in. The valleys make
take some time clear out, especially in the northern areas. So
have kept the lower high temperatures as highs may struggle to
warm up. Monday night fog may be more widespread and dense in the
interior valleys. Temperatures Tuesday may struggle to warm up as
well.

Tuesday night or Wednesday is the next chance for rain. This is
expected to mainly be in Humboldt and Del Norte counties. NBM
probabilities of over a half inch for 24 hours ending Thursday
morning range from 30 to 50 percent. Additional weak weather
systems are possible late in the week. For now it looks like the
stronger IVT values remain north of the area and amounts will be
relatively light. Probabilities of over 1 inch remain only around
30 to 60 percent for the 24 hours ending at 4pm Friday. MKK

&&

.AVIATION...The next bout of incoming rain has been precluded by
stratiform drizzle which has lowered visibility to less than a
mile at EKA/WFO as of 21z. KACV has reduced flight categories this
afternoon as a result, with IFR visibility and periods of LIFR
ceilings likely to last through the TAF period. Gusty southerly
winds with wind shear are probable at KACV and KCEC as model
soundings show stout winds aloft. KUKI has reduced visibility
presently and will likely continue tonight as similar conditions
set in with the incoming system, IFR/LIFR visibility and ceilings
lowering to around 1000 - 1500ft. /EYS

&&

.MARINE...Conditions remain hazardous as the next system approaches,
bringing stout winds and a chaotic sea state. The westerly swell
continues to build, currently being reported at 16 - 18 ft in as
many seconds, at the buoys as of 21z. Expect south winds to increase
significantly this evening with the incoming system. Gale Warnings
have been hoisted through Sunday morning over all area waters, with
the southern inners delaying a few hours behind the rest. NBM
indicates an 80-100% chance of frequent gale force gusts (greater
than or equal to 34 KTS) for the majority of northern and outer
waters.

On Sunday morning the final cold front of this system will sweep
through the waters bringing an end to the active weather we have had
for the past several days. Waves will gradually subside to around
10ft combined by Monday.

Less active weather is anticipated for next week with lower seas and
lighter winds through the entire week. The only main concern is a
weak system that could enhance the southerly winds around mid week
with small craft conditions possible.

&&

.HYDROLOGY...Much of Humboldt and Del Norte counties remain in a
flood watch for tonight and tomorrow. This is mainly for small
streams and urban areas when the cold front comes through. Rain
rates will be fairly high. Also, the small streams are already
elevated and may exceed their banks. The number of the mainstem
rivers are expected to remain at or reach action/monitor stage in
Del Norte and Humboldt counties, but at this point none are
expected to reach flood stage. The Smith river at Dr. Fine Bridge
continues to be the one with most potential to go higher than
expected so this will need to be watched. Currently the forecast
has it peaking at 29.5 feet which is over 3 feet below flood
stage.

&&

.BEACH HAZARDS...A westerly swell continues to move through the
waters at 16 to 18 feet in as many seconds. A couple of buoys were
reporting 18 feet at 18 seconds early this morning resulting in
large breakers near 24 feet. Larger Breakers in the 20 to 25 foot
range are anticipated through 9 PM this evening before subsiding a
bit tonight. Use great caution near beaches this weekend.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     High Surf Advisory until 9 PM PST this evening for CAZ101-
     103-104-109.

     Flood Watch through Sunday afternoon for CAZ101-102-105.

     High Wind Warning from 9 PM this evening to 6 AM PST Sunday
     for CAZ101.

     Wind Advisory from 6 PM this evening to 6 AM PST Sunday for
     CAZ102-104>106.

     Wind Advisory from midnight tonight to 6 AM PST Sunday for
     CAZ103.

     Flood Watch from 1 AM PST Sunday through Sunday afternoon
     for CAZ103-106.

     Wind Advisory from 1 AM to 8 AM PST Sunday for CAZ109-110.

     Wind Advisory from 6 AM to 1 PM PST Sunday for CAZ115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PST this evening for PZZ450-
     470-475.

     Gale Warning from 9 PM this evening to 6 AM PST Sunday for
     PZZ450-470-475.

     Small Craft Advisory until midnight PST tonight for PZZ455.

     Gale Warning from midnight tonight to 6 AM PST Sunday for
     PZZ455.

&&

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png

The radar

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

Open the radar archive at this moment

Event by event

4 flood, 1 strong wind. Local standard time, as filed.

Strong Wind, Coastal Del Norte

When
December 28, 8:00 PM PST to December 29, 2:00 AM PST
Where
Coastal Del Norte forecast zone
Measured
48 kt (55 mph) measured gust
Reported by
ASOS
Coordinates
41.745, -123.958 (the zone’s center; the record gives no point)

Wind gusts in excess of 50 mph resulted in downed trees on Highway 101 and other roads in Del Norte County. A peak wind gust of 55 mph was measured at the Crescent City Airport.

Flood, Humboldt

When
December 29, 6:00 AM PST to 9:00 AM PST
Where
Humboldt County, 0.24 mi W of Beatrice to 0.24 mi WNW of Beatrice
Cause
Heavy Rain
Reported by
Department of Highways
Coordinates
40.670, -124.204

Hookton Rd. closed due to flooding. The on and offramps to Highway 101 were also flooded and closed at the intersection with Hookton Rd.

Flood, Humboldt

When
December 29, 6:00 AM PST to 9:00 AM PST
Where
Humboldt County, 0.76 mi NNE of Bayside to 1.36 mi ENE of Bayside
Cause
Heavy Rain
Reported by
Department of Highways
Coordinates
40.841, -124.067

Old Arcata Road flooded at Jacoby Creek.

Flood, Mendocino

When
December 29, 10:00 AM PST to 3:00 PM PST
Where
Mendocino County, 2.31 mi SSE of Navarro
Cause
Heavy Rain
Reported by
Department of Highways
Coordinates
39.119, -123.515

Highway 128 completely flooded near Clark Road in the Navarro area.

Flood, Mendocino

When
December 29, 10:00 AM PST to 3:00 PM PST
Where
Mendocino County, 3.78 mi W of Navarro to 4.54 mi W of Navarro
Cause
Heavy Rain
Reported by
Department of Highways
Coordinates
39.159, -123.600

Highway 128 flooded along the North Fort of the Navarro River. Two feet of water reported on the roadway with multiple vehicles stranded.

What these are

Strong Wind
Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
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

More

Every storm in California in 2024Every state in 2024This day in weather historyWarnings in California, December 2024

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: 1230335, 1230319, 1230336, 1230337, 1230338.