The Bronco Fire ignited on August 17th, and burned roughly 25 acres. It occurred very close to I-15, and actually necessitated the closure of three northbound lanes on I-15.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
The episode as NWS SGX wrote it up.
The Bronco Fire ignited on August 17th, and burned roughly 25 acres. It occurred very close to I-15, and actually necessitated the closure of three northbound lanes on I-15. This resulted in major traffic delays.
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 San Diego, CA wrote its last area forecast discussion before the first event at Aug 17, 8:04 AM PST, 4 hours 11 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
904 AM PDT Wed Aug 17 2022
.SYNOPSIS...
Gradual drying will continue through Thursday with fewer
afternoon thunderstorms in the mountains and deserts. Another
influx of moisture on Friday and Saturday will increase chances
for afternoon thunderstorms in the mountains and deserts. This
will be followed by drying for Sunday and Monday with the smallest
chances for thunderstorms on Monday. Moisture and thunderstorm
chances will then begin to increase around the middle of next
week. High temperatures for inland areas will not be as hot on
Friday and Saturday with the influx of moisture, then warmer for
early next week with the drying.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.Morning Update...
Good morning to all! Another warm and muggy summer day is in store
today with highs into the 70s and 80s near the coast into the
mountain areas to the triple digits for parts of the Inland Empire
and deserts. Our monsoon flow will continue today, but with less
storm coverage than we have seen over the past couple of days. We
can expect isolated thunderstorms for the mountains later today,
with the best chances across the SBD County mountains. A similar
story is on tap for tomorrow with an isolated storm chance across
the mountains, with highs a touch lower for areas west of the
mountains.
More monsoonal moisture will enter the picture by Friday and
Saturday. We will continue to fine tune the forecast on this as
the exact trajectory and cloud cover associated with this
monsoonal moisture from the south is still a bit uncertain.
Further west would indicate more storm activity, while a
trajectory further east would lead to a drier pattern. So far, we
have begun to see hints of a drier forecast. Early next week
continues to look on the drier and warmer side.
.Previous Forecast (352 AM Today)...
.SHORT TERM (Today through Friday)...
There will be a drying trend for today and Thursday with fewer
afternoon thunderstorms in the mountains and deserts each day. For
today, initial development is expected along convergence
boundaries toward the mountain ridge tops during the late morning
and early afternoon with thunderstorms migrating toward the
deserts during the afternoon as the sea breeze moves inland. Some
thunderstorms could produce locally heavy rainfall with isolated
flash flooding. Moisture will begin to increase again on Friday
with NBM chances for measurable rainfall slightly greater than for
today and rainfall coverage and amounts from the local NAM-
bounded WRF a little greater than for today.
Through Thursday, there will be slight cooling of high
temperatures for the coast and valleys with not much change for
the mountains and deserts. Friday will not be quite as hot for
inland areas as moisture begins to increase. Areas of night and
morning coastal low clouds will extend locally inland into the far
western valleys in San Diego County and across portions of the
Orange County coastal plain.
&&
.LONG TERM (Saturday through Tuesday)...
The moisture influx will continue into Saturday with chances for
afternoon and early evening thunderstorms about the same as
earlier this week. This will be followed by drying for Sunday and
Monday with thunderstorm chances on Monday the lowest for the next
week. Moisture may begin to increase again around the middle of
next week, but with ECMWF ensemble output for precipitable water
showing greater spread between the wetter and drier members. With
the influx of moisture on Saturday, high temperatures for inland
areas will not be as hot. Then warmer high temperatures for inland
areas for early next week with the drying.
&&
.AVIATION...
171530Z...Coast...Areas of low clouds will clear by 16Z. Areas of
low clouds gradually increasing 02-10Z tonight. Where cigs form,
bases will be 600-1000 feet MSL with vis locally reduced 2-5SM,
especially on mesas. Scatter out Thursday 14-16Z.
Inland...ISOLD TSRA over the mountains after 19-01Z with CB bases
10000 feet MSL and tops to 35000 feet. Gusty and erratic winds and
brief heavy rain vcnty TSRA. SCT clouds AOA 15000 feet MSL after 04Z.
&&
.MARINE...
No hazardous marine weather is expected through Sunday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT this evening for San Bernardino and
Riverside County Valleys-The Inland Empire.
PZ...None.
&&
UPDATE/PUBLIC...APR/17
AVIATION/MARINE...MMThe national radar mosaic for the moment the first event began.
1 wildfire. Local standard time, as filed.
The Bronco Fire started near Matthews Rancho Road about 2 miles northwest of Devore, CA, and burned roughly 25 acres. The fire caused the closure of 3 northbound lanes on I-15 in the Cajon Pass, resulting in heavy traffic delays.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2022Every state in 2022This day in weather historyWarnings in California, August 2022
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: 1045800.