Winter Storm and High Wind in California, December 6 to 9, 2009

Name: Winter Storm and High Wind in California, December 6 to 9, 2009
Start: 2009-12-06T15:00
End: 2009-12-09T09:00
Location: California

December 6 to 9, 2009 · NWS HNX · 16 events in 10 counties and zones

A strong area of low pressure brought a wide swatch of precipitation into the Central California Interior. The precipitation arrived during the early morning hours of December 7th.

The toll

Deaths: 0
Injuries: 0
Property damage: $1.0 million
Crop damage: None recorded
Events: 16

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 HNX wrote it up.

A strong area of low pressure brought a wide swatch of precipitation into the Central California Interior. The precipitation arrived during the early morning hours of December 7th. Up to a half inch of rain fell on the San Joaquin Valley floor; a few flurries were mixed with the rain, but did not stick to the ground. Due to the very cold nature of the airmass behind the cold front, snow levels plummeted. A few inches of snow was reported in Oakhurst and Springville, at elevations between 2200 and 2400 feet. Yosemite Valley received 8 inches of new snow, and a foot of snow fell on the Grapevine, closing Interstate 5 through Tejon Pass. Highway 58, through the Tehachapi Pass at a similar elevation, also was closed by the snow.

Strong wind gusts developed over the Kern County desert portion of the Mojave Desert behind the cold front, and gusts approaching 80 mph were recorded during the evening of the 7th. At the Mojave Spaceport, severe wind gusts up to 80 mph caused extensive property damage at a festival. Local officials were able to evacuate attendees 36 minutes before the severe wind hit the area. Thankfully there were no injuries or fatalities reported. Several large temporary structures failed at the Mojave Spaceport. Local officials estimated the property damage around 1 million dollars. After the peak winds occurred, winds continued to gust over 60 mph for about 3 hours.

A short-wave ridge moved over the state on December 8th, bringing clear skies and light winds. Moring low temperatures in the central and southern San Joaquin Valley fell into the lower to mid 20s at the coldest locations during the early morning hours of the 8th, and only a few places had lows near 32 degrees. Similar lows were reported the following morning, and central and south Valley highs struggled to reach 50 on both December 8th and 9th.

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 Hanford, CA wrote its last area forecast discussion before the first event at Dec 6, 3:00 PM PST, 0 minutes earlier.

Area forecast discussion, Dec 6, 3:00 PM PST, 0 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
300 PM PST SUN DEC 6 2009

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE OVER THE AREA TONIGHT. THIS SYSTEM
WILL BRING COLD AIR ALONG WITH VALLEY RAIN...MUCH COOLER
TEMPERATURES AND LOW ELEVATION SNOWFALL BELOW THE PASSES AND INTO
THE FOOTHILLS EARLY MONDAY MORNING THROUGH MONDAY NIGHT FOR THE SAN
JOAQUIN VALLEY.

&&

.DISCUSSION...
THE FOCUS THIS AFTERNOON CONTINUES TO BE ON THE STORM FORECAST TO
REACH THE HANFORD WARNING/FORECAST AREA TONIGHT. THE 18Z NAM-12 IS
IN...AND DELAYS THE ARRIVAL OF THE COLDEST LOW-LEVEL AIR INTO THE
MERCED AREA UNTIL 00Z TUESDAY /WITH THE WET-BULB ZERO LINE NEAR THE
VALLEY FLOOR/...BUT STILL BRINGS IT DOWN TO FRESNO BY 09Z TUESDAY.
IF THIS IS CORRECT...RAIN OVER THE NORTHERN PART OF THE CENTRAL
VALLEY ZONES MIGHT NOT CHANGE OVER TO SNOW OR A RAIN/SNOW MIX UNTIL
THE EVENING COMMUTE. WILL KEEP THE CURRENT TIMING OF THE WINTER
WEATHER ADVISORY FOR NOW...AS ANY ACCUMULATIONS OF SNOW ON THE
VALLEY FLOOR MAY MAKE TRAVEL TREACHEROUS.

MODEL QPF GIVES TEHACHAPI AROUND AN INCH LIQUID EQUIVALENT. WITH THE
SNOW LEVEL LOWERING TO AROUND 3500 FEET...THERE WILL BE SEVERAL
INCHES ACCUMULATION ON THE PASSES HINDERING TRAVEL BETWEEN THE SAN
JOAQUIN VALLEY AND THE SOUTHLAND OR THE INDIAN WELLS VALLEY. THE
WINTER STORM WARNING FOR THE SOUTHERN SIERRA NEVADA AND THE
TEHACHAPI MOUNTAINS LOOKS ON TRACK.

THE NEXT CONCERN IS THE WIND DEVELOPING IN THE KERN COUNTY DESERTS
AHEAD OF THE FRONT. WINDS AT EDWARDS AFB HAVE ALREADY GUSTED TO 37
KTS...AND LIKELY WILL INCREASE THIS EVENING. HAVE ISSUED A WIND
ADVISORY FOR THE KERN COUNTY DESERTS FOR 00-08Z MONDAY...AND MAY
NEED ANOTHER ADVISORY FOR MONDAY NIGHT WITH THE POST-FRONTAL WINDS.

ALSO FOR MONDAY NIGHT...THE VERY COLD AIRMASS WILL POOL OVER THE SAN
JOAQUIN VALLEY. BOTH THE 12Z AND 18Z NAM-12 RUNS BROUGHT THE WET-
BULB ZERO LINE TO NEAR THE SURFACE AT FRESNO BY 09Z TUESDAY. LOWS IN
THE MID 20S WILL BE WIDESPREAD ACROSS THE RURAL PARTS OF THE
CENTRAL AND SOUTH VALLEY AND A FREEZE WATCH REMAINS IN PLACE FOR
TUESDAY MORNING.

THERE WILL BE A BREAK IN THE PRECIPITATION TUESDAY AND WEDNESDAY AS
A HIGHLY-AMPLIFIED RIDGE PIVOTS INTO CALIFORNIA BETWEEN TROUGHS. THE
NEXT TROUGH UNDERCUTS THE RIDGE WEDNESDAY EVENING...WITH THE GFS
BRINGING PRECIPITATION TO YOSEMITE BETWEEN 06-12Z THURSDAY. THIS
LOOKS TO BE A WARMER SYSTEM...WITH 850-MB TEMPERATURES REMAINING
ABOVE ZERO C.

THE THIRD STORM IS FORECAST TO MOVE INTO CALIFORNIA SATURDAY AND
SATURDAY NIGHT...BUT THE NEWEST RUNS CONTINUE THE TREND OF
WEAKENING THIS SYSTEM. WILL HAVE TO WATCH THE EVOLUTION OF THIS
SYSTEM OVER THE NEXT SEVERAL DAYS.

DATES FOR MEASURABLE SNOW IN BAKERSFIELD AND FRESNO...
/AMOUNTS IN INCHES/

BAKERSFIELD                    FRESNO

DECEMBER 11 1932...4.0         JANUARY 12 1930....2.5
JANUARY 25 1999....3.0         JANUARY 22 1962....1.5
MARCH 17 1922......2.5         DECEMBER 28 1911...1.5
MARCH 8 1974.......1.5         DECEMBER 20 1968...1.2
                               JANUARY 21 1962....0.7
                               JANUARY 1 1910.....0.6
                               DECEMBER 20 1998...0.5
                               JANUARY 1 1916.....0.5
                               MARCH 23 1929......0.2
                               JANUARY 10 1916....0.2
                               DECEMBER 24 1916...0.1
                               MARCH 23 1916......0.1

&&

.AVIATION...
A COLD STORM SYSTEM TRACKING THROUGH THE REGION WILL SPREAD AREAS
OF MVFR AND LOCAL IFR CONDITIONS IN RAIN AND HIGHER ELEVATION SNOW
ACROSS INTERIOR CENTRAL CALIFORNIA BETWEEN 03Z THIS EVENING AND
00Z TUESDAY. FREEZING/FROZEN PRECIPITATION COULD FALL AS LOW AS
THE VALLEY FLOOR IN THE MERCED AREA BY MONDAY AFTERNOON.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT PST TONIGHT FOR THE KERN COUNTY
DESERTS /CAZ098-099/.

FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR
THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY /CAZ089>092/.

WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST MONDAY FOR THE
CENTRAL SAN JOAQUIN VALLEY /CAZ089-090/.

WINTER STORM WARNING FROM 4 AM MONDAY TO MIDNIGHT PST MONDAY
NIGHT FOR THE FOOTHILLS AND HIGHER ELEVATIONS OF THE SOUTHERN
SIERRA NEVADA AND THE TEHACHAPI MOUNTAINS /CAZ093>097/.

&&

PUBLIC...SANGER
AVN/FW...JEB
SYNOPSIS...TLM

WEATHER.GOV/HANFORD

Hazardous weather outlook, Dec 6, 3:21 AM PST, 11 hours 39 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
321 AM PST SUN DEC 6 2009

CAZ089>092-071200-
WEST CENTRAL SAN JOAQUIN VALLEY-EAST CENTRAL SAN JOAQUIN VALLEY-
SOUTHWESTERN SAN JOAQUIN VALLEY-SOUTHEASTERN SAN JOAQUIN VALLEY-
321 AM PST SUN DEC 6 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE CENTRAL AND SOUTHERN
SAN JOAQUIN VALLEY.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A FREEZE WATCH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING FOR THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY. SEE THE
LATEST SFONPWHNX OR /WWUS76 KHNX/ FOR DETAILS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR
UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE.

WEATHER.GOV/HANFORD

CAZ093>097-071200-
MARIPOSA MADERA AND FRESNO COUNTY FOOTHILLS-
TULARE COUNTY FOOTHILLS-KERN COUNTY MOUNTAINS-
SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON-
TULARE COUNTY MOUNTAINS-
321 AM PST SUN DEC 6 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE KERN COUNTY MOUNTAINS
AND THE FOOTHILLS AND HIGHER ELEVATIONS OF THE SOUTHERN SIERRA
NEVADA.

.DAY ONE...TODAY AND TONIGHT

A WINTER STORM WATCH IS IN EFFECT FROM LATE TONIGHT THROUGH MONDAY
EVENING FOR THE KERN COUNTY MOUNTAINS AND THE FOOTHILLS AND HIGHER
ELEVATIONS OF THE SOUTHERN SIERRA NEVADA. SEE THE LATEST SFOWSWHNX
OR /WWUS46 KHNX/ FOR DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE WINTER STORM WATCH MENTIONED ABOVE WILL BE IN EFFECT UNTIL
MONDAY EVENING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR
UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE.

BSO

WEATHER.GOV/HANFORD

Event by event

8 frost/freeze, 3 strong wind, 3 winter storm, 1 winter weather, 1 high wind. Local standard time, as filed.

Strong Wind, Indian Wells Vly

When: December 6, 3:00 PM PST to December 7, 12:00 AM PST
Where: Indian Wells Vly forecast zone
Measured: 40 kt (46 mph) estimated gust
Property damage: $1,000
Reported by: Mesonet

Strong Wind, Se Kern Cty Desert

When: December 6, 3:00 PM PST to December 7, 12:00 AM PST
Where: Se Kern Cty Desert forecast zone
Measured: 40 kt (46 mph) estimated gust
Property damage: $1,000
Reported by: Mesonet

Winter Storm, Kern Cty Mtns

When: December 7, 4:00 AM PST to December 8, 12:00 AM PST
Where: Kern Cty Mtns forecast zone
Reported by: Trained Spotter

Winter Storm, S Sierra Mtns

When: December 7, 4:00 AM PST to 7:54 PM PST
Where: S Sierra Mtns forecast zone
Reported by: Trained Spotter

Winter Storm, Tulare Cty Mtns

When: December 7, 4:00 AM PST to 7:54 PM PST
Where: Tulare Cty Mtns forecast zone
Reported by: Trained Spotter

Winter Weather, S Sierra Foothills

When: December 7, 4:00 AM PST to 7:54 PM PST
Where: S Sierra Foothills forecast zone
Reported by: Trained Spotter

High Wind, Se Kern Cty Desert

When: December 7, 6:17 PM PST to December 8, 12:00 AM PST
Where: Se Kern Cty Desert forecast zone
Measured: 70 kt (81 mph) measured gust
Property damage: $1.0 million
Reported by: Mesonet

Strong Wind, Indian Wells Vly

When: December 7, 8:00 PM PST to December 8, 12:00 AM PST
Where: Indian Wells Vly forecast zone
Measured: 40 kt (46 mph) measured gust
Property damage: $1,000
Reported by: Mesonet

Frost/Freeze, W Central S.J. Valley

When: December 8, 12:00 AM PST to 9:00 AM PST
Where: W Central S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, E Central S.J. Valley

When: December 8, 12:00 AM PST to 9:00 AM PST
Where: E Central S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, Sw S.J. Valley

When: December 8, 12:00 AM PST to 9:00 AM PST
Where: Sw S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, Se S.J. Valley

When: December 8, 12:00 AM PST to 9:00 AM PST
Where: Se S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, W Central S.J. Valley

When: December 9, 12:00 AM PST to 9:00 AM PST
Where: W Central S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, E Central S.J. Valley

When: December 9, 12:00 AM PST to 9:00 AM PST
Where: E Central S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, Sw S.J. Valley

When: December 9, 12:00 AM PST to 9:00 AM PST
Where: Sw S.J. Valley forecast zone
Reported by: Mesonet

Frost/Freeze, Se S.J. Valley

When: December 9, 12:00 AM PST to 9:00 AM PST
Where: Se S.J. Valley forecast zone
Reported by: Mesonet

What these are

Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Frost/Freeze: Frost or temperatures at or below freezing during the growing season, usually filed for crop damage.

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

The same day elsewhere

Every storm in California in 2009 Every state in 2009 This day in weather history Warnings in California, December 2009

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: 209018, 209019, 208990, 208992, 208993, 208994, 209022, 209021, 209014, 209015, 209016, 209017, 209023, 209024, 209025, 209026.