California, 2017

Drought in California, February 1 to 28, 2017

February 1 to 28, 2017 · NWS STO · 2 events in 2 counties and zones

Long term drought impacts continued to decrease through the month of February, as a series of strong atmospheric river storms brought very wet conditions. This continued the wet pattern which began in the Fall, especially for the northern Sierra.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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.

Long term drought impacts continued to decrease through the month of February, as a series of strong atmospheric river storms brought very wet conditions. This continued the wet pattern which began in the Fall, especially for the northern Sierra. The northern Sierra had the second wettest February on record (8 Station Index). At the end of February, Lake Shasta was 114% of normal, Lake Oroville was 110%, Folsom Lake was 74%, and Don Pedro was 139%. New Melones Reservoir improved and began to catch up the other significant area reservoirs, at 107% of normal.

The U.S. Drought Monitor showed significant improvement over the area, with all areas of drought and abnormally dry removed and all of interior Northern California, in the 'None' category by the end of February.

Groundwater aquifers continued to recharge more slowly than the surface reservoirs, though the DWR Water Data Library showed signs of improvement in some areas.

Governor Jerry Brown declared a drought emergency for the entire state of California January 17, 2014 and this continued to be in effect. Governor Brown issued an executive order on May 9, 2016 that built on temporary statewide emergency water restrictions to establish longer-term water conservation measures, including permanent monthly water use reporting, new permanent water use standards in California communities and banned clearly wasteful practices such as hosing off sidewalks, driveways and other hardscapes.

Local emergency proclamations remain for Colusa, Calaveras, El Dorado, Glenn, San Joaquin, Shasta, Stanislaus, Sutter, Tuolumne, and Yuba counties. Plumas County no longer had a Local Emergency Proclamation. The cities of Live Oak (Sutter County), Lodi (San Joaquin County), Manteca (San Joaquin County), Portola (Plumas County), Ripon (San Joaquin County), and West Sacramento (Yolo County) continued to have local emergency proclamations . Drought task forces remain in Lake, Nevada, Placer, Plumas, Sacramento, San Joaquin, Stanislaus, Sutter, Tehama, Tuolumne, and Yolo counties to coordinate response to the drought.

The State Water Resources Control Board announced that urban Californians monthly water conservation was 25.1 percent in February, more than double the 11.9 percent savings in February 2016, when state-mandated conservation targets were in place.

The threat of dead or dying trees continued, with on-going tree-removal programs at the state and federal level.

The state continued to supply food assistance to those impacted by the drought, along with California Disaster Assistance Act money for those who have lost drinking water due to dry wells.

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 Jan 31, 9:00 PM PST, 3 hours earlier.

Area forecast discussion, Jan 31, 9:00 PM PST, 3 hours before
Area Forecast Discussion
National Weather Service Sacramento CA
900 PM PST Tue Jan 31 2017

.Synopsis...
Dry with patchy morning valley fog through Wednesday. Wet pattern
returns Wednesday night with heavier rain and mountain snow on
Thursday and Friday. The wet pattern may continue into next week.

&&

.Discussion...
High clouds are moving over the area this evening. Dewpoints are
up this evening but a better presence of high clouds tonight will
help to keep fog development patchy. Any breaks in the cloud layer
could lead to some rapid development of fog. A few sprinkles may
occur during the afternoon ahead of the main band which is still
on track to move into the area late Wednesday night and Thursday
morning. Current forecast is still on track so no changes.

.Previous Discussion (Tonight through Saturday)... Little overall
change is expected through Wednesday with patchy morning fog,
cool mornings, and mild afternoon temperatures continuing.

An approaching upper low and associated frontal system in the
eastern Pacific will bring a return of wet weather to NorCal
starting Wednesday night and continuing into the weekend. By
Friday, an inch or two rain will be possible in the valley with
1-2 feet of snow in the mountains above 6K ft; local amounts of 3
to 5 ft or more possible over the peaks. Gusty southerly winds
will also develop across the region on Thursday and again Friday.
A the winter storm watch has been upgraded to a warning for the
mountains valid for Wed night into Friday night. The wet pattern
may continue into Saturday, but taper off a bit, especially in the
Valley.    JClapp

&&
.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)

Unsettled pattern will continue across interior NorCal during the
extended period. Precipitation chances diminish Saturday night
into early Sunday as model guidance is less robust in building
ridging into the area briefly on Sunday. Lingering shower activity
will remain mainly over higher terrain.

Pattern becomes more active as an upper trough drops southward
and deepens along the West Coast. However, there is some model
uncertainty in terms of timing and evolution of this upper system.
The ECMWF absorbs an EPAC low pressure system while the GFS
remains out of phase. Regardless, upper system should move through
Sunday night into Monday with widespread precipitation and
another round of gusty winds. Snow levels will remain in the
5000-6000 feet range as the bulk of the precipitation moves
through. Cold air aloft will follow behind the frontal system with
potentially lower snow levels. Temperatures are expected to be
below average by the end of the forecast period.

&&

.AVIATION...

General VFR conditions across TAF sites the next 24 hours. Brief
period of MVFR to IRF conditions from KSMF southward Wednesday
morning. Increased high cloud cover should limit widespread fog
formation.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 10 PM Wednesday to 4 AM PST Saturday
for Mountains Southwestern Shasta County to Northern Lake County-
West Slope Northern Sierra Nevada-Western Plumas County/Lassen
Park.

Wind Advisory from 4 AM to 10 PM PST Thursday for Carquinez
Strait and Delta-Central Sacramento Valley-Clear Lake/Southern
Lake County-Motherlode-Northeast Foothills/Sacramento Valley-
Northern Sacramento Valley-Northern San Joaquin Valley-Southern
Sacramento Valley.

&&

Event by event

2 drought. Local standard time, as filed.

Drought, Northern San Joaquin Valley

When
February 1, 12:00 AM PST to February 28, 11:59 PM PST
Where
Northern San Joaquin Valley forecast zone
Reported by
State Official

The Household Water Supply Shortage Reporting System indicated there were some homes without well water due to dry wells. In February there were 314 in Stanislaus County, unchanged since January. There were 8 in San Joaquin County, unchanged from January. Many rural communities in the Northern San Joaquin Valley were still receiving food assistance as a direct result of the drought.

Drought, Motherlode/Camptonville to Groveland

When
February 1, 12:00 AM PST to February 28, 11:59 PM PST
Where
Motherlode/Camptonville to Groveland forecast zone
Reported by
State Official

The Household Water Supply Shortage Reporting System indicated there were homes without well water due to dry wells. In February there were 240 dry wells in Tuolumne County. Emergency drinking water projects helped communities address diminished groundwater supplies.

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

More

Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, February 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: 699844, 699890.