Alert archive / Nevada / Red Flag Warnings in 2026
Red Flag Warning 9, NWS Reno, NV
NWS Reno, NV issued this red flag warning at Aug 21, 2026, 7:37 AM PDT for Lassen County, Modoc County, California; 4 counties in Nevada. It took effect at Aug 22, 2026, 11:00 AM PDT. It was in force for 12 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Aug 21, 2026, 7:37 AM PDT (14:37 UTC)
- In effect from
- Aug 22, 2026, 11:00 AM PDT
- Expired
- Aug 22, 2026, 11:00 PM PDT
- In force
- 12 hr
- Issued by
- NWS Reno, NV
Counties Lassen County, CA, Modoc County, CA, Douglas County, NV, Lyon County, NV, Storey County, NV, Washoe County, NV
The radar
The Reno radar (KRGX), 49 km from the middle of the area, began a volume at 14:41 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Reno, NV (KREV), launched 12:00Z, 2.6 hours before the alert went out and 154 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3091 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 0 m²/s²
- 0-3 km storm-relative helicity
- 61 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
908 WWUS85 KREV 211437 RFWREV URGENT - FIRE WEATHER MESSAGE National Weather Service Reno NV 737 AM PDT Fri Aug 21 2026 CAZ270-278-NVZ458-221445- /O.UPG.KREV.FW.A.0008.260822T1800Z-260823T0600Z/ /O.NEW.KREV.FW.W.0009.260822T1800Z-260823T0600Z/ Surprise Valley California-Eastern Lassen County- Northern Washoe County- 737 AM PDT Fri Aug 21 2026 ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 11 PM PDT SATURDAY FOR GUSTY WINDS AND LOW HUMIDITY FOR NORTHEASTERN CALIFORNIA AND FAR NORTHEASTERN NEVADA... The National Weather Service in Reno has issued a Red Flag Warning for gusty winds and low humidity, which is in effect from 11 AM to 11 PM PDT Saturday. The Fire Weather Watch is no longer in effect. * CHANGES...Upgraded the Fire Weather Watch to a Red Flag Warning. * Affected Area...Fire Weather Zone 270 Surprise Valley California, Fire Weather Zone 278 Eastern Lassen County, Fire Weather Zone 458 Northern Washoe County. * Winds...Southwest 15 to 25 mph with gusts up to 40 mph. * Humidity...As low as 12 percent. * Duration...3 to 6 hours. * Impacts...The combination of gusty winds and low humidity can cause fire to rapidly grow in size and intensity before first responders can contain them. PRECAUTIONARY/PREPAREDNESS ACTIONS... Avoid outdoor activities that can cause a spark near dry vegetation, such as yard work, target shooting, or campfires. Follow local fire restrictions. Check weather.gov/reno for updates and livingwithfire.info for preparedness tips. && $$ NVZ420-221445- /O.NEW.KREV.FW.W.0009.260822T1800Z-260823T0600Z/ Northern Sierra Front including Carson City, Douglas, Storey, Southern Washoe, Western Lyon, and Far Southern Lassen Counties- 737 AM PDT Fri Aug 21 2026 ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 11 PM PDT SATURDAY FOR GUSTY WINDS AND LOW HUMIDITY FOR THE NORTHERN SIERRA FRONT... The National Weather Service in Reno has issued a Red Flag Warning for gusty winds and low humidity, which is in effect from 11 AM to 11 PM PDT Saturday. * Affected Area...Fire Weather Zone 420 Northern Sierra Front including Carson City, Douglas, Storey, Southern Washoe, Western Lyon, and Far Southern Lassen Counties. * Winds...Southwest 15 to 25 mph with gusts up to 40 mph. * Humidity...As low as 18 percent. * Duration...3 to 6 hours. * Impacts...The combination of gusty winds and low humidity can cause fire to rapidly grow in size and intensity before first responders can contain them. PRECAUTIONARY/PREPAREDNESS ACTIONS... Avoid outdoor activities that can cause a spark near dry vegetation, such as yard work, target shooting, or campfires. Follow local fire restrictions. Check weather.gov/reno for updates and livingwithfire.info for preparedness tips. && $$ http://weather.gov/reno
2 follow-up statements
717 WWUS85 KREV 220805 RFWREV URGENT - FIRE WEATHER MESSAGE National Weather Service Reno NV 105 AM PDT Sat Aug 22 2026 CAZ270-278-NVZ420-458-230600- /O.CON.KREV.FW.W.0009.260822T1800Z-260823T0600Z/ Surprise Valley California-Eastern Lassen County- Northern Sierra Front including Carson City, Douglas, Storey, Southern Washoe, Western Lyon, and Far Southern Lassen Counties- Northern Washoe County- 105 AM PDT Sat Aug 22 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 11 PM PDT THIS EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR NORTHEASTERN CALIFORNIA AND NORTHWESTERN NEVADA... * CHANGES...No changes. * Affected Area...Fire Weather Zone 270 Surprise Valley California, Fire Weather Zone 278 Eastern Lassen County, Fire Weather Zone 420 Northern Sierra Front including Carson City, Douglas, Storey, Southern Washoe, Western Lyon, and Far Southern Lassen Counties, Fire Weather Zone 458 Northern Washoe County. * Winds...Southwest 15 to 25 mph with gusts up to 40 mph. * Humidity...As low as 12 percent. * Duration...3 to 6 hours between 11 AM and 11 PM PDT. * Impacts...The combination of gusty winds and low humidity can cause fire to rapidly grow in size and intensity before first responders can contain them. PRECAUTIONARY/PREPAREDNESS ACTIONS... Avoid outdoor activities that can cause a spark near dry vegetation, such as yard work, target shooting, or campfires. Follow local fire restrictions. Check weather.gov/reno for updates and livingwithfire.info for preparedness tips. && $$ http://weather.gov/reno
709 WWUS85 KREV 230617 RFWREV URGENT - FIRE WEATHER MESSAGE National Weather Service Reno NV 1117 PM PDT Sat Aug 22 2026 CAZ270-278-NVZ420-458-230730- /O.EXP.KREV.FW.W.0009.000000T0000Z-260823T0600Z/ Surprise Valley California-Eastern Lassen County- Northern Sierra Front including Carson City, Douglas, Storey, Southern Washoe, Western Lyon, and Far Southern Lassen Counties- Northern Washoe County- 1117 PM PDT Sat Aug 22 2026 ...RED FLAG WARNING HAS EXPIRED FOR GUSTY WINDS AND LOW HUMIDITY FOR NORTHEASTERN CALIFORNIA AND NORTHWESTERN NEVADA... Winds have diminished over northeastern California and northwestern Nevada. Therefore, the Red Flag Warning has been allowed to expire. Please continue use caution and heed any instructions from local emergency management with any ongoing wildfires in the area such as the Hawk Fire tonight. $$ http://weather.gov/reno
What forecasters said that day
The local office's own words before this red flag warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before this red flag warning went out at Aug 21, 2:30 AM PDT, 5 hours 7 minutes earlier. Its key messages:
- * A downward temperature trend starts today with seasonal temperatures expected by early next week. * Increasing westerly gusts today and Saturday lead to elevated to near critical fire conditions for northeast CA and northwest NV. * Isolated shower and thunderstorm potential returns for the NV Basin and Range, and south of US-50 this afternoon into the weekend.
Area forecast discussion, Aug 21, 2:30 AM PDT, 5 hours 7 minutes before
Area Forecast Discussion
National Weather Service Reno NV
230 AM PDT Fri Aug 21 2026
.KEY MESSAGES...
* A downward temperature trend starts today with seasonal
temperatures expected by early next week.
* Increasing westerly gusts today and Saturday lead to elevated
to near critical fire conditions for northeast CA and northwest
NV.
* Isolated shower and thunderstorm potential returns for the NV
Basin and Range, and south of US-50 this afternoon into the
weekend.
&&
.DISCUSSION...
The broad upper-level ridge over the Four Corners region will
continue to influence the weather pattern, maintaining a southerly
flow of monsoonal moisture into the region. A weak upper-level
trough will move across northern California and Oregon today
through Saturday, bringing increased winds and slightly modifying
the airmass, though temperatures remain above seasonal averages.
Temperatures will be slowly decreasing this weekend with afternoon
highs in the 90s for western NV/NE CA, and upper 70s to mid 80s
for Sierra communities.
West to southwest winds will increase across the region this
afternoon and peaking on Saturday. Afternoon gusts of 25-35 mph
are expected, particularly for northeastern California and
northern Washoe County, with isolated gusts up to 40 mph possible
in exposed areas. These conditions, coupled with low relative
humidity, will lead to elevated to critical fire weather
conditions, especially on Saturday.
Monsoonal moisture will continue to advect northward into the
region, with PWAT values around 0.6-0.8 inches. This moisture,
combined with daytime heating, will lead to isolated showers and
thunderstorms. Chances are low (1-10%) today and confined to the
eastern Sierra and western Nevada Basin and Range. By Saturday,
chances increase to 10-40% and become more widespread, especially
for the eastern Sierra and the Nevada Basin and Range. Instability
remains with marginal MUCAPE 100-500 J/kg, but strong DCAPE to
1000 J/kg, suggesting that any storms could produce gusty outflow
winds up to 40 mph, brief heavy rain, small hail and frequent
lightning. On Sunday, conditions begin to dry out slightly, with
lower chances for convection 10-20% across the NV Basin and Range.
The pattern next week remains dominated by a persistent upper-level
ridge over the Southwest and a longwave trough in the PacNW. This
will continue to support seasonal temperatures. Highs will
generally remain in the low to mid-90s for western NV and northeast
CA valleys, and in the upper 70s to mid-80s for Sierra communities.
Monsoonal moisture will continue to stream northward around the
western flank of the ridge, leading to very low chances (~5%) of
isolated, diurnally-driven showers and thunderstorms, primarily
over the higher terrain and NV Basin and Range.
-HC
&&
.AVIATION...
VFR conditions continue with mid to high level clouds through the
forecast period. SHRA/TSRA has a 5-10% chance to develop near
KMMH/KHTH/KBAN this afternoon, increasing to 10-20% for Saturday.
Winds increase this afternoon with westerly gusts to around 25
kts. Then on Saturday gusts potentially increase to 30-35 kts in
the afternoon.
-HC
&&
.FIRE WEATHER...
* Elevated fire risk today with an increase of west to southwest
winds of 20-30 mph and min RH of 10-20% for eastern Lassen, the
Surprise Valley, northern Washoe, the Sierra Front, and portions
of Mono counties. Conditions deteriorate to critical by Saturday
over northeast CA and northwest NV with gusts to 30-35 mph with
a 10-60% chance of exceeding 40 mph in isolated locations
including the Surprise Valley, and similar min RH compared to
Friday. Critical conditions are expected to last for 3-6 hours
between Saturday afternoon and early evening. For these reasons,
we issued a Fire Weather Watch from 11 AM through 11 PM
Saturday for northern Washoe and eastern Lassen counties, and
Surprise Valley in Modoc County. Other areas in western NV and
Mono County will see gusts of 25-30 mph on Saturday, creating
elevated fire weather conditions in the afternoon.
-HC/HRICH
&&
.REV Watches/Warnings/Advisories...
NV...Fire Weather Watch from Saturday morning through Saturday
evening NVZ458.
CA...Fire Weather Watch from Saturday morning through Saturday
evening CAZ270-278.
&&The office that day
Everything else NWS Reno, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 11:22 AM PDT | Lake Wind Advisory | REV | Lassen, Plumas, Sierra | 36 hr |
Nearby
Red Flag Warnings in Nevada, 2026Red Flag Warnings in California, 2026Every red flag warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.