California, 2015

Drought in California, August 1 to 31, 2015

August 1 to 31, 2015 · NWS STO · 8 events in 8 counties and zones

The long term drought continued through August with little change. Without a snow pack for late spring/early summer, reservoirs across the area by the end of the month were continuing to drop well below normal levels.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
8

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.

The long term drought continued through August with little change. Without a snow pack for late spring/early summer, reservoirs across the area by the end of the month were continuing to drop well below normal levels. All major reservoirs across the state were less that 40% of capacity by the end of the month. Folsom Lake was down to 20% of capacity, approaching near-record low levels for August, seen last in 1977.

Extreme drought continued to be detected by the U.S. Drought Monitor across most the region, with exceptional drought for the northern San Joaquin Valley, the central and southern Sacramento Valley, the Burney Basin and the Sierra.

The continued dry weather and periods of hot temperatures left vegetation parched and ready to burn. Wildfire activity was well above normal levels.

Governor Jerry Brown declared a drought emergency for the entire state of California January 17, 2014 and this continued to be in effect.

Local Emergency Proclamations have been issued for El Dorado, Glenn, Lake, Plumas, San Joaquin, Shasta, Sutter, Tuolumne, and Yuba counties. The cities of Live Oak Lodi, and Ripon continue in a drought emergency. Drought task forces have been established in Butte, Lake, Nevada, Placer, Plumas, Sacramento, San Joaquin, Stanislaus, Sutter, Tehama, Tuolumne, and Yolo counties to coordinate response to the drought.

Mandatory water reductions of 25 percent as ordered by Governor Brown continue to be in effect statewide, the first time such mandatory restrictions have been enacted. Actual usage across California dropped an average of 27 percent.

Agriculture has been heavily impacted, with numerous farm and farm related jobs lost. The UC Davis Center for Watershed Sciences released a new report indicating that California’s ongoing drought will impact the state’s agricultural economy this year by an estimated $2.7 billion and eliminate more than 21,000 jobs. The state continued to supply food assistance to those impacted, along with California Disaster Assistance Act money for those who have lost drinking water due to dry wells. Approximately 743,642 boxes of food were distributed to 391,003 households in affected communities that suffered high levels of unemployment from the drought

Low runoff in streams and rivers on fish and ecological continues to cause adverse affects on forests and wildlife, including the endangered Delta Smelt and winter run Chinook Salmon.

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 Jul 31, 9:21 PM PST, 2 hours 39 minutes earlier.

Area forecast discussion, Jul 31, 9:21 PM PST, 2 hours 39 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1021 PM PDT FRI JUL 31 2015

.SYNOPSIS...
A SLOW COOLING TREND CONTINUES INTO NEXT WEEK. DAYTIME HIGHS NEAR
NORMAL BY SUNDAY AND AT OR BELOW NORMAL MUCH OF NEXT WEEK.
SCATTERED MOUNTAIN THUNDERSTORMS THROUGH MONDAY AS MONSOON
MOISTURE IS PULLED NORTHWARD...ELSEWHERE CONTINUED DRY.

&&

.DISCUSSION...
MODERATE DELTA THIS EVENING WITH GUSTS TO 35 MPH THROUGH THE
DELTA. THIS HAS LEAD TO COOLING OVER THE SOUTHERN SAC VALLEY...BUT
STILL WARM OVER THE NORTHERN VALLEY. WINDS ARE GENERALLY LIGHT
AWAY FROM THE TYPICAL DELTA INFLUENCED LOCATIONS. NO SHOWERS OR
THUNDERSTORMS PRESENTLY IN THE AREA...BUT CANNOT RULE OUT
DEVELOPMENT OVERNIGHT SOUTH OF HIGHWAY 50 AND WILL LEAVE SLIGHT
CHANCES. CURRENT FORECAST IS ON TRACK AND NO EVENING UPDATE IS
NEEDED.

.PREVIOUS DISCUSSION...THE UPPER LEVEL RIDGING WHICH BROUGHT A
HEAT WAVE ACROSS THE AREA THIS WEEK IS GIVING WAY. MONSOONAL
MOISTURE WITH A DISTURBANCE MOVING THROUGH NORCAL IS SPREADING
SHOWERS AND A FEW ISOLATED THUNDERSTORMS IN THE MOUNTAINS. THE
MAIN CHANGE FOR THE REST OF THE AREA IS A BIG DROP IN TEMPERATURES
TODAY, WITH TEMPERATURES AT 3 PM 6 TO 11 DEGREES LOWER THAN THIS
TIME YESTERDAY. THIS IS DUE TO A COOLER AIRMASS...ONSHORE FLOW
WITH THE DELTA BREEZE...AND INCREASED CLOUD COVER. MOISTURE WITH
THE MONSOONAL FLOW IS MAKING IT FEEL MORE HUMID THAN
NORMAL...THOUGH...WHICH IS COUNTERING SOME OF THE COOLING AFFECTS.

THE DISTURBANCE IS A NICELY DEFINED VORTMAX, CLEARLY VISIBLE
ROTATING ON THE SATELLITE LOOP. THIS IS MOVING NORTHWARD THROUGH
THE AREA, CURRENT CENTERED AROUND GLENN COUNTY.

PRECIPITATION HAS MAINLY BEEN FOCUSED OVER THE MOUNTAINS TODAY
EXCEPT FOR SOME LIGHT SHOWERS/SPRINKLES IN THE MORNING. THE MOST
NOTABLE STORM SO FAR IS A THUNDERSTORMS THAT DEVELOPED NEAR THE
SIERRA CREST AND TRACKED TO THE NORTHWEST OVER BLUE CANYON. THIS
SYSTEM PASSED CLOSE TO THE LOWELL FIRE...BRINGING WINDS GUSTING TO
AROUND 31 MPH. THERE WERE QUITE A FEW LIGHTNING STRIKES WITH THIS
STORM...AT LEAST ONE OF WHICH STARTED A NEW WILDFIRE NEAR ALTA. AS
EXPECTED...THERE HAS BEEN LIMITED RAIN WITH THESE INITIAL
STORMS...WHICH INCREASES THE FIRE DANGER. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO GET PROGRESSIVELY MORE WET AS MORE
MOISTURE PUSHES NORTHWARD INTO THE AREA TONIGHT AND THROUGH THE
WEEKEND.

THE OVERALL AIRMASS COOLS A BIT MORE ON SATURDAY AS THE UPPER
RIDGE SHIFTS EASTWARD A BIT IN RESPONSE TO AN UPPER LOW OFF THE
CENTRAL CA COAST SHIFTING COASTWARD. A CONTINUED STRONG DELTA
BREEZE WILL KEEP DAYTIME TEMPERATURES IN DELTA INFLUENCED AREAS AT
OR BELOW NORMAL. MOISTURE...INSTABILITY AND OROGRAPHIC LIFT WILL
BRING ANOTHER DAY OF ISOLATED THUNDERSTORMS OVER THE MOUNTAINS
SATURDAY. UPPER RIDGE AXIS SHIFTS FARTHER INLAND ON SUNDAY WITH AN
INCREASE IN ONSHORE FLOW BRINGING STILL COOLER TEMPERATURES.
DAYTIME HIGHS ON SUNDAY SHOULD COME IN CLOSE TO OR EVEN BELOW
NORMAL MOST AREAS. MOUNTAIN THUNDERSTORMS WILL CONTINUE TO
REDEVELOP IN THE AFTERNOON BUT AREA OF EMPHASIS WILL LIKELY SHIFT
TO THE NORTHERN MOUNTAINS UNDER A MORE SOUTHERLY FLOW ALOFT. UPPER
TROUGH DEVELOPMENT IN THE EASTERN PACIFIC WITH SOUTHWEST FLOW
ALOFT OVER THE NORTH STATE SHOULD SHIFT ANY AFTERNOON THUNDERSTORM
DEVELOPMENT TO THE SIERRA CASCADE CREST ON MONDAY. INCREASED
ONSHORE FLOW AND COOLER AIRMASS WILL BRING DOWN HIGH TEMPERATURES
TO BELOW NORMAL FOR THIS TIME OF YEAR WITH THESE BELOW NORMAL
TEMPERATURES LASTING THROUGH MUCH OF THE COMING WEEK.

&&
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)

MODELS ADVERTISING OFFSHORE UPPER LOW WITH UPPER RIDGING OVER THE
PLAINS EARLY NEXT WEEK. SOUTHWESTERLY FLOW ALOFT OVER NORCAL
WITH MODEL DIFFERENCES IN STRENGTH OF EMBEDDED VORT MAXES. DIFFERENCES
GROW THROUGH MIDWEEK AS EC PROGS MAIN UPPER LOW INLAND WHILE THE
GFS IS ABOUT 48 HOURS SLOWER. WILL MAINTAIN DRY FORECAST BUT
POTENTIAL MAY EXIST FOR SOME DEEP MOIST CONVECTION OVER THE
MOUNTAINS TUESDAY AND BEYOND. HIGH TEMPERATURES FORECAST TO BE
NEAR TO SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED FORECAST
PERIOD.

&&

.AVIATION...

MAINLY VFR CONDITIONS NEXT 24 HOURS AT TAF SITES. GUSTY WINDS TO
35 MPH THROUGH THE DELTA.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

Event by event

8 drought. Local standard time, as filed.

Drought, Northern Sacramento Valley

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

Agriculture continued to be impacted in August bringing a significant loss of jobs. Tree mortality across the Valley increased, including even normally drought resistant oak trees. Golf courses faced pressure to use less water and were doing so, bringing a dry, brown appearance to the turf, and some remained shut down due to a lack of water. Many people reduced landscape watering at homes or removed grass lawns. Grass fires enhanced by the dry conditions were common.

Drought, Central Sacramento Valley

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

Agriculture continued to be impacted in August bringing a significant loss of jobs. Tree mortality across the Valley increased, including even normally drought resistant oak trees. Golf courses faced pressure to use less water and were doing so, bringing a dry, brown appearance to the turf, some remained shut down due to a lack of water. Many people reduced landscape watering at homes or removed grass lawns.

Drought, Southern Sacramento Valley

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

Agriculture continued to be impacted in August bringing a significant loss of jobs. Tree mortality across the Valley increased, including even normally drought resistant oak trees. Golf courses faced pressure to use less water and were doing so, bringing a dry, brown appearance to the turf, some remained shut down due to a lack of water. Many people reduced landscape watering at homes or removed grass lawns. Grass fires enhanced by the dry conditions were common.

Drought, Mountains Southwest Shasta County to Northern Lake County

When
August 1, 12:00 AM PST to 11:59 PM PST
Where
Mountains Southwest Shasta County to Northern Lake County forecast zone
Reported by
Newspaper

The drought continues to impact Lake County, with a reduced number of vines and irrigation through the summer, reducing their harvest potential. Agriculture and related businesses have continued to lose jobs.

Drought, Clear Lake/Southern Lake County

When
August 1, 12:00 AM PST to 11:59 PM PST
Where
Clear Lake/Southern Lake County forecast zone
Reported by
Newspaper

The drought continues to impact Lake County, with a reduced number of vines and irrigation through the summer, reducing their harvest potential. Agriculture and related businesses have continued to lose jobs. Wildfires were enhanced, such as the Jerusalem Fire.

Drought, Carquinez Strait and Delta

When
August 1, 12:00 AM PST to August 31, 11:59 PM PST
Where
Carquinez Strait and Delta forecast zone
Reported by
Newspaper

The drought continues to impact agriculture in the Delta. Wildlife such as the endangered Delta smelt and winter run Chinook Salmon are suffering losses due to changes from the drought, such as an increase in water temperature and salinity levels. Wildfires were enhanced, such as the Jerusalem Fire.

Drought, West Slope Northern Sierra Nevada

When
August 1, 12:00 AM PST to 11:59 PM PST
Where
West Slope Northern Sierra Nevada forecast zone
Reported by
Newspaper

Dry conditions from the long term drought caused millions of trees to die. This also enhanced wildfires in the northern Sierra.

Drought, Mt Shasta/Western Plumas County

When
August 1, 12:00 AM PST to 11:59 PM PST
Where
Mt Shasta/Western Plumas County forecast zone
Reported by
Newspaper

Dry conditions from the long term drought caused many trees to die. This also enhanced wildfires in the mountains.

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 2015Every state in 2015This day in weather historyWarnings in California, August 2015

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: 597874, 597875, 597876, 597877, 597879, 597880, 597885, 597887.