Drought in California, December 1 to 31, 2020

Name: Drought in California, December 1 to 31, 2020
Start: 2020-12-01T00:00
End: 2020-12-31T23:59
Location: California

December 1 to 31, 2020 · NWS STO · 5 events in 5 counties and zones

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 STO wrote it up.

Northern California typically experiences a wet season, October through May, and a dry season May through September. Last year's water year, October 2019 through September 2020, was one of the driest on records. This likely contributed to the U.S. Drought Monitor's decision to place portions of interior northern California into extreme drought on September 29, 2020. Portions of Shasta, Tehama, Butte, Glenn, Colusa, Yolo, Solano, Yuba, Nevada, and Sacramento counties remain placed extreme drought. The rest of interior northern California was placed into severe drought (D2) on December 8; however, the state of California has not announced that these locations are in drought.

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 Sacramento, CA wrote its last area forecast discussion before the first event at Nov 30, 2:38 PM PST, 9 hours 22 minutes earlier.

Area forecast discussion, Nov 30, 2:38 PM PST, 9 hours 22 minutes before

Area Forecast Discussion
National Weather Service Sacramento CA
238 PM PST Mon Nov 30 2020

.SYNOPSIS...
Persistent dry weather will continue with mostly clear skies and
above average high temperatures. Breezy north to east winds are
expected Tuesday into Wednesday.

&&

.DISCUSSION...
Quiet weather continues today with some scattered high clouds
pushing south over Northern California. Temperatures are
generally mild, in the 60s across most of the Valley with 40s and
50s over the higher elevations. Light north to northwesterly flow
will continue through the day.

The trough that brought us these mostly high clouds is forecast
to continue to push inland to our north and east. As it does,
this will cause pressure gradients to tighten as high pressure
builds in over our area. Subsequently breezy north to easterly
flow is expected to increase by Tuesday morning with breezy
conditions continuing over the Northern Sierra Tuesday night into
Wednesday morning.

Patchy morning frost will continue to be possible as this high
pressure pattern remains in place. Lows in the Valley are
forecast to generally be in the 30s with some areas in the San
Joaquin Valley dipping below freezing.

&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)...

Dry and mild weather will continue under ridging over the west
coast throughout the extended forecast period. There is high
confidence we will likely remain dry with little day to day change for
the first half of December as indicated by cluster analysis. We
will continue to see above average high temperatures and cool
morning lows, closer to climatology. This pattern will also
continue to yield inversions that will keep the upper foothills
and lower mountain regions a bit warmer than average overnight.
Stay tuned as models are hinting at a pattern change some time mid
month with some possible moisture returning to our area.
&&

.AVIATION...

VFR conditions with winds generally under 10 kts. MVFR possible
KSAC and KMOD due to BR around 12-17 UTC. Increasing winds over
Northern Sacramento Valley terminals expected after 6 UTC with
gusts to 15 knots by 16 UTC.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

Event by event

5 drought. Local standard time, as filed.

Drought, Southern Sacramento Valley

When: December 1, 12:00 AM PST to December 31, 11:59 PM PST
Where: Southern Sacramento Valley forecast zone
Reported by: Drought Monitor

For the month of December, the U.S. Drought Monitor kept all of Yolo County, and portions of Sacramento, Sutter, Solano counties in extreme drought (D3). They also noted on this month's call the following impacts for the Sacramento Valley: low groundwater levels, dry stock pond, and poor range-land and pasture conditions. Some ranchers have even stated they've started selling livestock. Additionally, The California Department of Water Resources announced the initial water allocation of 10% for the State Water Project (December 1st).

Drought, Mountains Southwestern Shasta County to Western Colusa County

When: December 1, 12:00 AM PST to December 31, 11:59 PM PST
Where: Mountains Southwestern Shasta County to Western Colusa County forecast zone
Reported by: Drought Monitor

For the month of December, the U.S. Drought Monitor kept all of zone 63, which covers western Tehama, Glenn, and Colusa counties in extreme drought (D3). They also noted on this month's call the following impacts for the Sacramento Valley: low groundwater levels, dry stock pond, and poor range-land and pasture conditions. Some ranchers have even stated they've started selling livestock. Additionally, The California Department of Water Resources announced the initial water allocation of 10% for the State Water Project (December 1st).

Drought, Central Sacramento Valley

When: December 1, 12:00 AM PST to December 31, 11:59 PM PST
Where: Central Sacramento Valley forecast zone
Reported by: Drought Monitor

For the month of December, the U.S. Drought Monitor kept most of Glenn and Colusa, and Sutter counties along with the western portions of Butte and Yuba counties in extreme drought (D3). They also noted on this month's call the following impacts for the Sacramento Valley: low groundwater levels, dry stock pond, and poor range-land and pasture conditions. Some ranchers have even stated they've started selling livestock. Additionally, The California Department of Water Resources announced the initial water allocation of 10% for the State Water Project (December 1st).

Drought, Northern Sacramento Valley

When: December 1, 12:00 AM PST to December 31, 11:59 PM PST
Where: Northern Sacramento Valley forecast zone
Reported by: Drought Monitor

For the month of December, the U.S. Drought Monitor kept all of zone 15, portions of Shasta and Tehama counties, into extreme drought (D3).They also noted on this month's call the following impacts for the Sacramento Valley: low groundwater levels, dry stock pond, and poor range-land and pasture conditions. Some ranchers have even stated they've started selling livestock. Additionally, The California Department of Water Resources announced the initial water allocation of 10% for the State Water Project (December 1st).

Drought, Shasta Lake/North Shasta County

When: December 1, 12:00 AM PST to December 31, 11:59 PM PST
Where: Shasta Lake/North Shasta County forecast zone
Reported by: Drought Monitor

For the month of December, the U.S. Drought Monitor kept the majority of zone 13, which covers Shasta County, in extreme drought (D3). The California Department of Water Resources announced the initial water allocation of 10% for the State Water Project (December 1st).

What these are

Drought: A drought reaching severe (D2) or worse on the US Drought Monitor, or with notable impacts.

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

The same day elsewhere

Every storm in California in 2020 Every state in 2020 This day in weather history Warnings in California, December 2020

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: 934554, 934555, 934560, 934564, 934566.