Alert archive / California / Red Flag Warnings in 2021

Red Flag Warning 10, NWS Reno, NV

July 3, 20217 counties in California; 5 counties in Nevada

NWS Reno, NV issued this red flag warning at Jul 3, 2021, 1:41 AM PDT for 7 counties in California; 5 counties in Nevada. It took effect at Jul 3, 2021, 11:00 PM PDT. It was in force for 7 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
Jul 3, 2021, 1:41 AM PDT (08:41 UTC)
In effect from
Jul 3, 2021, 11:00 PM PDT
Expired
Jul 4, 2021, 6:22 AM PDT
In force
7 hr
Issued by
NWS Reno, NV

Counties El Dorado County, CA, Lassen County, CA, Modoc County, CA, Nevada County, CA, Placer County, CA, Plumas County, CA, Sierra County, CA, Douglas County, NV, Lyon County, NV, Mineral County, NV, Storey County, NV, Washoe County, NV

The radar

The Reno radar (KRGX), 56 km from the middle of the area, began a volume at 08:38 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 00:00Z, 8.7 hours before the alert went out and 162 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.

Skew-T log-pSkew-T log-p diagram, Reno, NV at 00:00Z on 2021-07-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 280 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Reno, NV at 00:00Z on 2021-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
280 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
3236 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

406 
WWUS85 KREV 030841
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
141 AM PDT Sat Jul 3 2021

CAZ270-278-NVZ420-458-041800-
/O.UPG.KREV.FW.A.0009.210704T0800Z-210704T1800Z/
/O.NEW.KREV.FW.W.0010.210704T0600Z-210704T1800Z/
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-
141 AM PDT Sat Jul 3 2021

...RED FLAG WARNING IN EFFECT FROM 11 PM THIS EVENING TO 11 AM
PDT SUNDAY FOR THUNDERSTORMS AND STRONG OUTFLOW WINDS FOR PORTIONS 
OF WESTERN NEVADA AND NORTHEASTERN CALIFORNIA...

The National Weather Service in Reno has issued a Red Flag
Warning for thunderstorms and strong outflow winds, which is in
effect from 11 PM this evening to 11 AM PDT Sunday. The Fire
Weather Watch is no longer in effect.

* CHANGES...UPGRADED TO RED FLAG WARNING.

* Affected Area...Fire Zone 270 Surprise Valley California, Fire 
  Zone 278 Eastern Lassen County, Fire Zone 420 Northern Sierra 
  Front including Carson City, Douglas, Storey, Southern Washoe, 
  Western Lyon, and Far Southern Lassen Counties and Fire Zone 
  458 Northern Washoe County.

* Thunderstorms...Dry, fast-moving thunderstorms could form late
  this evening and sweep northward through Sunday morning.

* Outflow Winds...Gusts to 40 mph will be possible.

* Impacts...Little to no rainfall with these storms will promote 
  a higher potential for multiple new fire starts from 
  lightning, and may combine with strong outflow winds to cause 
  a 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.

&&

$$

CAZ271-272-NVZ421-041800-
/O.UPG.KREV.FW.A.0009.210704T0600Z-210704T1500Z/
/O.NEW.KREV.FW.W.0010.210704T0600Z-210704T1800Z/
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-
Southern Sierra Front including Alpine, Northern Mono, Southern
Lyon, and Western Mineral Counties-
141 AM PDT Sat Jul 3 2021

...RED FLAG WARNING IN EFFECT FROM 11 PM THIS EVENING TO 11 AM
PDT SUNDAY FOR THUNDERSTORMS AND STRONG OUTFLOW WINDS FOR PORTIONS
OF THE EASTERN SIERRA...WESTERN NEVADA...AND THE GREATER LAKE
TAHOE AND TRUCKEE AREA...

The National Weather Service in Reno has issued a Red Flag
Warning for thunderstorms and strong outflow winds, which is in
effect from 11 PM this evening to 11 AM PDT Sunday. The Fire
Weather Watch is no longer in effect.

* CHANGES...UPGRADED TO RED FLAG WARNING.

* Affected Area...Fire Zone 271 Western Lassen, Eastern Plumas, 
  and Eastern Sierra Counties, Fire Zone 272 Greater Lake Tahoe 
  and Truckee Area, Fire Zone 421 Southern Sierra Front 
  including Alpine, Northern Mono, Southern Lyon and Western 
  Mineral Counties.

* Thunderstorms...Dry, fast-moving thunderstorms could form late 
  Saturday evening and sweep northward through Sunday morning.

* Outflow Winds...Gusts to 40 mph will be possible.

* Impacts...Little to no rainfall with these storms will promote 
  a higher potential for multiple new fire starts from 
  lightning, and may combine with strong outflow winds to cause 
  a 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
898 
WWUS85 KREV 040918
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
218 AM PDT Sun Jul 4 2021

CAZ270>272-278-NVZ420-421-458-041800-
/O.CON.KREV.FW.W.0010.000000T0000Z-210704T1800Z/
Surprise Valley California-
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
Northern Sierra Front including Carson City, Douglas, Storey,
Southern Washoe, Western Lyon, and Far Southern Lassen Counties-
Southern Sierra Front including Alpine, Northern Mono, Southern
Lyon, and Western Mineral Counties-Northern Washoe County-
218 AM PDT Sun Jul 4 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 AM PDT THIS
MORNING FOR THUNDERSTORMS AND STRONG OUTFLOW WINDS FOR PORTIONS
OF WESTERN NEVADA AND NORTHEASTERN CALIFORNIA...

* CHANGES...Updated wording.

* Affected Area...Fire Zone 270 Surprise Valley California, Fire 
  Zone 271 Western Lassen, Eastern Plumas, and Eastern Sierra 
  Counties, Fire Zone 272 Greater Lake Tahoe and Truckee Area, 
  Fire Zone 278 Eastern Lassen County, Fire Zone 420 Northern 
  Sierra Front including Carson City, Douglas, Storey, Southern 
  Washoe, Western Lyon, and Far Southern Lassen Counties, Fire 
  Zone 421 Southern Sierra Front including Alpine, Northern 
  Mono, Southern Lyon, and Western Mineral Counties and Fire 
  Zone 458 Northern Washoe County.

* Thunderstorms...Dry, fast-moving thunderstorms will continue to
  develop and sweep northward through this morning.

* Outflow Winds...Gusts to 40 mph will be possible.

* Impacts...Little to no rainfall with these storms will promote 
  a higher potential for multiple new fire starts from 
  lightning, and may combine with strong outflow winds to cause 
  a 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
047 
WWUS85 KREV 041322
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
622 AM PDT Sun Jul 4 2021

CAZ270>272-278-NVZ420-421-458-041430-
/O.CAN.KREV.FW.W.0010.000000T0000Z-210704T1800Z/
Surprise Valley California-
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
Northern Sierra Front including Carson City, Douglas, Storey,
Southern Washoe, Western Lyon, and Far Southern Lassen Counties-
Southern Sierra Front including Alpine, Northern Mono, Southern
Lyon, and Western Mineral Counties-Northern Washoe County-
622 AM PDT Sun Jul 4 2021

...RED FLAG WARNING IS CANCELLED FOR THUNDERSTORMS AND STRONG
OUTFLOW WINDS FOR PORTIONS OF WESTERN NEVADA AND NORTHEASTERN 
CALIFORNIA...

The National Weather Service in Reno has cancelled the Red Flag
Warning.

Lightning activity has decreased through the early morning hours
with only some showers now moving through Lassen, Washoe, and
Pershing counties. A lightning strike or two remains possible, but
there is no longer enough coverage to support a Red Flag Warning.
Expect wetter variety storms to form later today, as early as late
morning, with potential for new fire starts from lightning that 
occurs outside of storm cores. 

$$

http://weather.gov/reno

The office that day

Everything else NWS Reno, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 3, 3:23 PM PDTSpecial Weather StatementREVSierra22 min
Jul 2, 5:41 PM PDTSpecial Weather StatementREV49 min
Jul 2, 5:56 PM PDTAreal Flood AdvisoryREVWashoe3 hr
Jul 3, 2:09 PM PDTSpecial Weather StatementREV36 min
Jul 3, 4:23 PM PDTSpecial Weather StatementREV22 min

Nearby

Red Flag Warnings in California, 2021Red Flag Warnings in Nevada, 2021Every red flag warning in 2021

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.