Wildfire in California, August 16 to 31, 2020

Name: Wildfire in California, August 16 to 31, 2020
Start: 2020-08-16T00:00
End: 2020-08-31T23:59
Location: California

August 16 to 31, 2020 · NWS STO · 5 events in 3 counties and zones

The toll

Deaths: 2
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.

During mid August, moisture from tropical storm Fausto moved along the coast of southern CA and made landfall over central and northern California. This system, combined with the an oppressive high pressure system that had predominately dry air, caused widespread dry thunderstorms to develop. Thousands of lightning strikes occurred overnight, which combined with the critical dry fuels, led to massive wildfire development. The August, the North, the LNU, and SCU Complexes all started between August 15 and 17.

The August Complex is still ongoing as of October 29, is the largest fire in California history, and is spread across the county warning areas of weather forecast offices Sacramento and Eureka. One fatality and injury occurred on August 27 at the August Complex due to a vehicular accident, many structures were destroyed or damaged.

The LNU and SCU complexes are mainly within the county warning area of weather forecast office Monterey; however, both fires spread into Sacramento's forecast area.

The LNU Complex caused significant damage in Solano County, including 2 fatalities, the evacuation of Vacaville and Fairfield, and the closure of I-80. Yolo County was also affected by the fires and had evacuations and road closures. 3 Fatalities occurred in Napa County. It has been difficult to find detailed data, but there were 5 injuries that occurred, 4 civilian and 1 first responded. The LNU Complex finally becomes fully extinguished by October 1, 2020.

The SCU Complex covered large swaths of land over Santa Clara, Alameda, Contra Costa, San Joaquin, Merced, and Stanislaus counties. Per the last CalFire incident update, 6 injuries occurred, 4 were first responder and 2 were civilian. The fires burned caused significant damage over the area. The SCU Complex finally becomes fully contained on October 1, 2020.

Finally, the North Complex was also started by lightning on August 17 at 8AM PST. It is still on going at the time of this preparation. Fire activity occurred for the month of August, but extreme grow of this fire would not happen until September.

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 Aug 15, 9:58 PM PST, 2 hours 2 minutes earlier.

Area forecast discussion, Aug 15, 9:58 PM PST, 2 hours 2 minutes before

Area Forecast Discussion
National Weather Service Sacramento CA
1058 PM PDT Sat Aug 15 2020

.SYNOPSIS...
Prolonged heatwave will impact the region through the middle of
next week. Daytime temperatures will be 10 to 20 degrees above
normal with limited overnight relief. Isolated dry thunderstorms
possible over the Valley and mountains late tonight through
tomorrow. Slight chance of afternoon showers/thunderstorms over
the mountains this weekend into Monday.

&&

.DISCUSSION...
Plethora of mid/high clouds will spread over Norcal tonite and Sun
keeping temps uncomfortably warm tonite, and limiting record max
temps on Sun. NBM Forecast Records table shows SAC, DTS, SCK may
near, tie or break records with DTS, SAC and about 50/50 and SCK
less than 50/50. Less cloud cover Mon and Tue push probability of
records higher with records extending farther north up towards RDD
on Tue.

Forecast NAM Bufkit soundings in the valley show very little
elevated CAPE in the moisture layer progressing Nwd. Chances of
thunder look very low at our TAF sites, albeit a few member
"paintballs" show higher REFs in the Valley, thinking more in line
of a few high-based sprinkles. Higher probability of thunder up in
Shasta Co Sun morning as shown in the HREF Prob of Comp REF.

Heat not only affecting people/animals, but also aviation. Density
altitude at our Valley TAF sites expected to increase to 2500-3500
ft as temps exceed triple digits during the next few days.    JHM

.Previous Discussion...

Very interesting summer forecast for this weekend. Large amplitude
high pressure ridge will remain centered over the Desert SW
through midweek, causing an extensive and dangerous heatwave for
much of the Western US, including NorCal. Valley temperatures at
2pm are already ranging 104 to 108 degrees and should top off
around 105 to 112 degrees.

A shortwave along the ridge is bringing Pacific moisture and
instability into California. These shortwaves have been producing
more uplift and therefore thunderstorms than models have generally
been forecasting. Thunderstorms and weak radar returns have been
forming along the Central Coast and moving northeast into the
Central Valley and Central Sierra. Currently seeing weak radar
returns over northern San Joaquin Valley this afternoon, but
surface is so dry that precip is not expected. However, isolated
thunderstorms forecast over the Sierra are popping up this
afternoon.

Models continue to depict another shortwave along the ridge moving
through NorCal late tonight through tomorrow. Current CAMS
continue to suggest the possibility for isolated thunderstorms
spreading north to south through the Valley and mountains late
tonight through tomorrow. Best chance of thunderstorms is
generally after 5 am, though could see them begin to form earlier.
Mid to upper level moisture is abundant with PWATs around 1 inch
but instability looks weak, so confidence is generally low for
thunderstorm formation. However, as mentioned before, the fact
that the models have not completely captured the convective nature
of previous shortwaves this week increases confidence somewhat.
Due to extremely dry lower levels, if any thunderstorms do form
they will produce little to no rainfall which could cause fire
starts. The Fire Weather Watch has been upgraded to a Red Flag
Warning as any fire starts could rapidly grow given the heat,
primed fuels, and unstable nature of the atmosphere.

Along with the chance of thunderstorms will be the likelihood of
cloud cover across the area tomorrow. This will likely dampen
daytime temperatures somewhat, so have lowered the temperatures
slightly. However, it will still be very hot with Valley highs
around 103 to 106 degrees with oppressive overnight lows in the
mid 70s to 80s.

Beyond Sunday, there is a slight chance for thunderstorms over the
Sierra and southern Cascades. If storms form they should stay
confined to the terrain. Heights are forecast to rise Monday and
Tuesday as high pressure continues to build over the Great Basin
area. High temperatures will generally be in the 105 to 110 degree
range for the Valley. Unfortunately, we won't see much in terms
of overnight relief as highs will span the 70s and 80s until
midweek. As a reminder this is a significant and dangerous heat
event. Heat related illness to humans and animals is likely with
extended outdoor exposure. Heat is the number one weather-related
killer in the U.S. Take necessary precautions to stay hydrated,
cool, and safe during this prolonged heatwave. HEC

&&

.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...
Our upper level ridge will slowly begin to push to the south and
east for the extended period. This will result in a gradual easing
of temperatures across interior NorCal, back to around 5 to 10
degrees above average by next weekend. The deterministic GFS wants
to bring in some tropical moisture into next weekend but it is
clearly an outlier at this time when looking at the ensembles as
they keep it well to our south and west. The forecast is expected
to remain dry throughout the period.

-CJM

&&

.AVIATION...
VFR conditions the next 24 hrs. Isolated afternoon thunderstorms
possible over higher elevations of the Coast Range and northern
Sierra Nevada until 03Z. Isolated high-based thunderstorms
possible after 06Z Sunday. Surface winds generally below 10 kts
except for in the northern Sac Valley where southerly winds up to 15
knots are possible until 03z. As temps exceed 100 degrees the next
few days, density altitude will increase to 2500 to 3500 feet at the
Valley TAF sites.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 5 AM to 8 PM PDT Sunday for Burney Basin
and Northeast Plateau in Shasta County Including Northwest
Lassen NF north of Lassen NP-Carquinez Strait and Delta-Central
Sacramento Valley in Glenn, Colusa, Yuba, Northern Sutter, and
Butte County Below 1000 Ft-Eastern Mendocino NF-Eastern Portion
of Shasta/Trinity NF-Northern Sacramento Valley to Southern
Tehama County Line Below 1000 Ft-Northern San Joaquin Valley in
San Joaquin and Stanislaus Counties Below 1000 ft-Northern
Sierra Foothills from 1000 to 3000 Ft. Includes portions of
Shasta-Trinity and Butte Units-Northern Sierra Including Lassen
NP and Plumas and Lassen NF/S West of the Sierra Crest (West of
Evans Peak-Grizzly Peak-Beckworth Peak)-Southeast Edge Shasta-
Trinity NF and Western Portions of Tehama-Glenn Unit-Southern
Sacramento Valley in Yolo-Sacramento Far Western Placer,
southern Sutter and Solano County Below 1000 Ft.

Excessive Heat Warning until 9 PM PDT Wednesday for Carquinez
Strait and Delta-Central Sacramento Valley-Motherlode-Mountains
Southwestern Shasta County to Western Colusa County-Northeast
Foothills/Sacramento Valley-Northern Sacramento Valley-Northern
San Joaquin Valley-Southern Sacramento Valley.

&&

Event by event

5 wildfire. Local standard time, as filed.

Wildfire, Northern San Joaquin Valley

When: August 16, 12:00 AM PST to August 31, 11:59 PM PST
Where: Northern San Joaquin Valley forecast zone
Reported by: Fire Department/Rescue

The SCU Complex started on August 16 and eventually becomes contained on October 1, 2020. It covered Santa Clara, Alameda, Contra Costa, San Joaquin, Merced, and Stanislaus counties which span the county warning areas of Monterey and Sacramento offices. This fire ends up burning a total of 396, 624 acres, destroying 136 structures and 86 minor structures, and damaging 26 structures. 6 injuries were reported, 4 of which were first responders and 2 civilian; however, detailed data for injuries have been hard to come by. Finally, evacuations and road closures occurred. The majority of this fire complex burned in Monterey's county warning area.

Wildfire, Mountains Southwestern Shasta County to Western Colusa County

When: August 16, 12:00 AM PST to August 31, 11:59 PM PST
Where: Mountains Southwestern Shasta County to Western Colusa County forecast zone
Reported by: Fire Department/Rescue

The August Complex was started by lightning on August 16 and 17, initially over the Mendocino National Forest. Since then, the fire has grown extensively and currently spans two National Weather Service county warning areas, Sacramento and Eureka. Counties that have been affected are Tehama, Glenn, Colusa, Lake, Trinity, Mendocino, and Humboldt counties. The fire is still on going and is 1,032, 648 acres, but is 93 percent contained as of October 29, 2020 when this data is being prepared. It has destroyed 54 structures and damaged 6 structures. 1 fire fighter fatality and an associated injury occurred via a vehicular accident while on the line in Eureka's forecast area.

Wildfire, Southern Sacramento Valley

When: August 17, 12:00 AM PST to August 31, 11:59 PM PST
Where: Southern Sacramento Valley forecast zone
Deaths: 1 direct, 0 indirect
Reported by: Fire Department/Rescue

CalFire reported a total of 5 fatalities for the LNU Complex, 2 of which occurred in Solano County which is in Sacramento's county warning area and 3 in Napa County which is in Monterey's county warning area. The first death recorded is of a man who chose not to evacuate his home in rural Vacaville. Officials completed a subsequent check on the man and found him deceased.

Wildfire, Southern Sacramento Valley

When: August 17, 12:00 AM PST to August 31, 11:59 PM PST
Where: Southern Sacramento Valley forecast zone
Deaths: 1 direct, 0 indirect
Reported by: Fire Department/Rescue

CalFire reported a total of 5 fatalities for the LNU Complex, 2 of which occurred in Solano County which is in Sacramento's county warning area and 3 in Napa County which is in Monterey's county warning area. The second death recorded is of a man who lived in a rural area of the greater Vacaville area and did not have running water or electricity on the property. Cause of death is likely due to fire and asphyxiation from smoke. Date of death is estimated based on news articles and information.

Wildfire, Southern Sacramento Valley

When: August 17, 12:00 AM PST to August 31, 11:59 PM PST
Where: Southern Sacramento Valley forecast zone
Reported by: Fire Department/Rescue

The LNU Complex started on August 17 and will eventually become contained on October 2, 2020. This fire ends up burning a total of 363, 220 acres, destroying 1491 structures, including an NWS COOP site, and damaging 232 structures. For Solano County, 42,00 acres were burned, 309 homes were destroyed, 854 structures were damaged, and 1,426 utility poles were replaced. Many evacuations occurred, including larger sized populations such as Fairfield, Vacaville, and Travis Air force Base. Multiple road closures happened as well, including Interstate 80 for a brief period. Finally 5 deaths, which are detailed and recorded as separate events, and 5 injuries happened because of the fire. Injury information has been hard to come by with the latest information being 4 civilian and 1 first responder injury.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Wildfire, Southern Sacramento Valley	2020-08-20	82	Male	Permanent Home	Direct
Wildfire, Southern Sacramento Valley	2020-08-20	64	Male	Permanent Home	Direct

What these are

Wildfire: A fire burning in wildland vegetation, with its acreage and damage where known.

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, August 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: 919160, 919165, 919148, 919149, 919155.