Alert archive / California / Red Flag Warnings in 2021

Red Flag Warning 16, NWS Reno, NV

September 9, 20216 counties in California

NWS Reno, NV issued this red flag warning at Sep 9, 2021, 10:33 AM PDT for 6 counties in California. It took effect at Sep 9, 2021, 11:00 PM PDT. It was in force for 24 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
Sep 9, 2021, 10:33 AM PDT (17:33 UTC)
In effect from
Sep 9, 2021, 11:00 PM PDT
Expired
Sep 10, 2021, 11:00 PM PDT
In force
24 hr
Issued by
NWS Reno, NV

Counties El Dorado County, CA, Lassen County, CA, Nevada County, CA, Placer County, CA, Plumas County, CA, Sierra County, CA

The radar

The Beale AFB radar (KBBX), 84 km from the middle of the area, began a volume at 17:35 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, 5.6 hours before the alert went out and 211 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 12:00Z on 2021-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3286 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

963 
WWUS85 KREV 091733
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
1033 AM PDT Thu Sep 9 2021

CAZ271-272-278-101745-
/O.UPG.KREV.FW.A.0015.210910T0600Z-210911T0600Z/
/O.NEW.KREV.FW.W.0016.210910T0600Z-210911T0600Z/
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
1033 AM PDT Thu Sep 9 2021

...RED FLAG WARNING IN EFFECT FROM 11 PM THIS EVENING TO 11 PM 
PDT FRIDAY FOR THE TAHOE BASIN AND NORTHEAST CALIFORNIA FOR 
THUNDERSTORMS AND GUSTY WINDS AND LOW HUMIDITY TONIGHT AND 
FRIDAY...

The National Weather Service in Reno has issued a Red Flag
Warning for gusty winds and low humidity, which is in effect from
11 PM this evening to 11 PM PDT Friday. The Fire Weather Watch is
no longer in effect.

* Changes...Upgrade 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 and Fire Zone 278 Eastern Lassen County.

* Thunderstorms will move through the region tonight into Friday
  morning. Dry lightning strikes and gusty outflow winds are
  possible. There is potential for wetting rains in some of the
  stronger showers and thunderstorms.

* Winds...Winds will increase through tonight especially in the
  higher terrain and over ridgelines. Expect southwest 15 to 25 
  mph with gusts to 35 mph tonight into Friday. Gusts may exceed 
  60 mph in the higher elevations around the Tahoe Basin.

* Humidity...Minimum values of 15 to 25 percent Friday afternoon.

* Impacts...Lightning can create new fire starts and may combine
  with gusty winds to cause a fire to rapidly grow in size and
  intensity.

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
3 follow-up statements
420 
WWUS85 KREV 102031
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
131 PM PDT Fri Sep 10 2021

CAZ271-272-278-110600-
/O.CON.KREV.FW.W.0016.000000T0000Z-210911T0600Z/
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
131 PM PDT Fri Sep 10 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING FOR THE TAHOE BASIN AND NORTHEAST CALIFORNIA FOR
THUNDERSTORMS AND GUSTY WINDS AND LOW HUMIDITY TONIGHT AND
FRIDAY...

* Changes....Removed thunderstorm threat. 

* Affected Area...Fire Zone 271 Western Lassen, Eastern Plumas, 
  and Eastern Sierra Counties, Fire Zone 272 Greater Lake Tahoe 
  and Truckee Area and Fire Zone 278 Eastern Lassen County.

* Winds...Winds southwest 15 to 25 mph with gusts to 35 mph
  through this evening. Gusts may exceed 50 mph in the higher 
  elevations around the Tahoe Basin.

* Humidity...Minimum values of 15 to 25 percent.

* Impacts...Gusty winds could cause a fire to rapidly grow in 
  size and intensity.

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
800 
WWUS85 KREV 102049
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
149 PM PDT Fri Sep 10 2021

CAZ271-272-278-110600-
/O.CON.KREV.FW.W.0016.000000T0000Z-210911T0600Z/
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
149 PM PDT Fri Sep 10 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING FOR THE TAHOE BASIN AND NORTHEAST CALIFORNIA FOR
GUSTY WINDS...

* Changes....Removed thunderstorm threat.

* Affected Area...Fire Zone 271 Western Lassen, Eastern Plumas, 
  and Eastern Sierra Counties, Fire Zone 272 Greater Lake Tahoe 
  and Truckee Area and Fire Zone 278 Eastern Lassen County.

* Winds...Winds southwest 15 to 25 mph with gusts to 35 mph 
  through this evening. Gusts may exceed 50 mph in the higher 
  elevations around the Tahoe Basin.

* Humidity...Minimum values of 15 to 25 percent.

* Impacts...Gusty winds could cause a fire to rapidly grow in 
  size and intensity.

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
208 
WWUS85 KREV 110532
RFWREV

URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
1032 PM PDT Fri Sep 10 2021

CAZ271-272-278-110645-
/O.EXP.KREV.FW.W.0016.000000T0000Z-210911T0600Z/
Western Lassen, Eastern Plumas, and Eastern Sierra Counties-
Greater Lake Tahoe and Truckee Area-Eastern Lassen County-
1032 PM PDT Fri Sep 10 2021

...RED FLAG WARNING WILL EXPIRE AT 11 PM PDT THIS EVENING FOR THE
TAHOE BASIN AND NORTHEAST CALIFORNIA FOR GUSTY WINDS...

Winds have diminished well below critical levels and the threat 
for red flag conditions has ended.

$$

http://weather.gov/reno

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 1:20 PM PDTLake Wind AdvisoryREVAlpine, El Dorado, Nevada, Placer31 hr

Nearby

Red Flag Warnings in California, 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.