A cold front moved into the central California interior during the late evening of January 9th. Gusts to around 35 mph accompanied the front as it moved through the central and southern San Joaquin Valley during the overnight hours. Gusty winds continued over the Kern County deserts through the day on the 10th, with gusts of 45-55 mph recorded from Ridgecrest and Inyokern south to Edwards AFB and Rosamond. This was a very cold system, with the snow level lowering to around 1500 feet during the night of the 9th-10th. The Grapevine was closed due to snow on the morning of January 10th. A few flurries were reported mixed with rain over the eastern edge of the San Joaquin Valley in Tulare County, including Porterville, during the evening of the 10th, but no measurable snow fell on the Valley floor.
The extremely cold airmass pooled over the central and southern San Joaquin Valley, and with no mechanism to mix it out, brought freezing temperatures to the region for over a week. The coldest parts of the Valley fell into the lower 20s nearly every night from January 12th through the 20th, threatening the citrus and other crops. Freeze warnings were issued for the San Joaquin Valley from the 10th until the 17th as low temperatures repeatedly dropped well into the 20s. Even temperatures in the Kern County desert fell to the single digits in the coldest locations during this period, especially on the 13th and 14th.  Locations in the highest elevations of the southern Sierra Nevada dropped well below zero. In fact, Tuolumne Meadows had two consecutive mornings during the 12th and 13th when temperatures fell to just below 20 degrees below zero.

Winter Weather in KERN CTY MTNS, CALIFORNIA
From 10-JAN-13 07:00:00 to 11-JAN-13 04:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Frost/Freeze in E CENTRAL S.J. VALLEY, CALIFORNIA
From 11-JAN-13 05:00:00 to 11-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in W CENTRAL S.J. VALLEY, CALIFORNIA
From 12-JAN-13 05:00:00 to 12-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in W CENTRAL S.J. VALLEY, CALIFORNIA
From 11-JAN-13 05:00:00 to 11-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in E CENTRAL S.J. VALLEY, CALIFORNIA
From 12-JAN-13 05:00:00 to 12-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SW S.J. VALLEY, CALIFORNIA
From 12-JAN-13 05:00:00 to 12-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SE S.J. VALLEY, CALIFORNIA
From 12-JAN-13 05:00:00 to 12-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SW S.J. VALLEY, CALIFORNIA
From 15-JAN-13 05:00:00 to 15-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SW S.J. VALLEY, CALIFORNIA
From 11-JAN-13 05:00:00 to 11-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SE S.J. VALLEY, CALIFORNIA
From 11-JAN-13 05:00:00 to 11-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in W CENTRAL S.J. VALLEY, CALIFORNIA
From 13-JAN-13 05:00:00 to 13-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in E CENTRAL S.J. VALLEY, CALIFORNIA
From 13-JAN-13 05:00:00 to 13-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in W CENTRAL S.J. VALLEY, CALIFORNIA
From 14-JAN-13 05:00:00 to 14-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SW S.J. VALLEY, CALIFORNIA
From 13-JAN-13 05:00:00 to 13-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in E CENTRAL S.J. VALLEY, CALIFORNIA
From 14-JAN-13 05:00:00 to 14-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SW S.J. VALLEY, CALIFORNIA
From 14-JAN-13 05:00:00 to 14-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SE S.J. VALLEY, CALIFORNIA
From 13-JAN-13 05:00:00 to 13-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SE S.J. VALLEY, CALIFORNIA
From 14-JAN-13 05:00:00 to 14-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in W CENTRAL S.J. VALLEY, CALIFORNIA
From 15-JAN-13 05:00:00 to 15-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in E CENTRAL S.J. VALLEY, CALIFORNIA
From 15-JAN-13 05:00:00 to 15-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Frost/Freeze in SE S.J. VALLEY, CALIFORNIA
From 15-JAN-13 05:00:00 to 15-JAN-13 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet