Alert archive / Nevada / Red Flag Warnings in 2021

Red Flag Warning 6, NWS Las Vegas, NV

April 23, 2021Mohave County, Arizona; Clark County, Lincoln County, Nye County, Nevada; San Bernardino County, California

NWS Las Vegas, NV issued this red flag warning at Apr 23, 2021, 12:38 PM MST for Mohave County, Arizona; Clark County, Lincoln County, Nye County, Nevada; San Bernardino County, California. It took effect at Apr 24, 2021, 11:00 AM MST. It was in force for 33 hr. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 23, 2021, 12:38 PM MST (19:38 UTC)
In effect from
Apr 24, 2021, 11:00 AM MST
Expired
Apr 25, 2021, 8:00 PM MST
In force
33 hr
Issued by
NWS Las Vegas, NV

Counties Mohave County, AZ, San Bernardino County, CA, Clark County, NV, Lincoln County, NV, Nye County, NV

The radar

The Las Vegas radar (KESX), 94 km from the middle of the area, began a volume at 19:42 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.

What was reported inside it

TimeReportWhereRemark
Apr 25, 1:27 PM MSTNON-TSTM WND GST 613 Sw Mercury, NVPEAK WIND GUST OF 61 MPH. GUSTS OF THIS MAGNITUDE OCCURRED BETWEEN 127 PM AND 207 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 7.6 hours before the alert went out and 28 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, Las Vegas, NV at 12:00Z on 2021-04-23Temperature 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, Las Vegas, NV at 12:00Z on 2021-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 square meters per square second.1939587897Sfc1 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
3889 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

949 
WWUS85 KVEF 231938
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
1238 PM PDT Fri Apr 23 2021

AZZ101-102-CAZ229-NVZ461>466-241200-
/O.UPG.KVEF.FW.A.0004.210424T1800Z-210426T0300Z/
/O.NEW.KVEF.FW.W.0006.210424T1800Z-210426T0300Z/
Lake Mead NRA/Colorado River-AZ side-
Northwest Deserts/Northwest Plateau-Lower Colorado River Valley-
Lincoln County/Ely Dispatch-Nye County Deserts/Las Vegas Dispatch-
Sheep Range-Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
Lake Mead NRA/Colorado River-NV side-
1238 PM PDT Fri Apr 23 2021 /1238 PM MST Fri Apr 23 2021/

...RED FLAG WARNING IN EFFECT FROM 11 AM SATURDAY TO 8 PM SUNDAY 
FOR STRONG WINDS AND LOW HUMIDITY FOR SOUTHERN NEVADA AND
NORTHWEST ARIZONA...

* AFFECTED AREA...In Arizona...Fire weather zones 101 and 102. In
  California...Fire weather zone 229. In Nevada...Fire weather 
  zones 461, 462, 463, 464, 465, and 466. 

* TIMING...Late Saturday morning through Sunday evening.

* WIND...South-southwest 15-25 mph with gusts to 40 mph Saturday
  and 20-30 mph with gusts over 50 mph on Sunday. Winds will not
  be as strong overnight but will remain gusty.

* HUMIDITY...Minimum humidity 7-15 percent Saturday afternoon and
  slightly higher Sunday afternoon. Humidity will recovery to 
  greater than 15 percent Saturday night.

* IMPACTS...any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
4 follow-up statements
855 
WWUS85 KVEF 241201
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
501 AM PDT Sat Apr 24 2021

AZZ101-102-CAZ229-NVZ461>466-250000-
/O.CON.KVEF.FW.W.0006.210424T1800Z-210426T0300Z/
Lake Mead NRA/Colorado River-AZ side-
Northwest Deserts/Northwest Plateau-Lower Colorado River Valley-
Lincoln County/Ely Dispatch-Nye County Deserts/Las Vegas Dispatch-
Sheep Range-Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
Lake Mead NRA/Colorado River-NV side-
501 AM PDT Sat Apr 24 2021 /501 AM MST Sat Apr 24 2021/

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 
8 PM SUNDAY FOR STRONG WINDS AND LOW HUMIDITY FOR SOUTHERN NEVADA
AND NORTHWEST ARIZONA...

* AFFECTED AREA...In Arizona...Fire weather zones 101 and 102. 
  InCalifornia...Fire weather zone 229. In Nevada...Fire weather 
  zones 461, 462, 463, 464, 465, and 466. 

* TIMING...Late Saturday morning through Sunday evening.

* WIND...South-southwest 15-25 mph with gusts to 40 mph 
  Saturday and 20-30 mph with gusts over 50 mph on Sunday. 
  Winds will not be as strong overnight but will remain gusty.

* HUMIDITY...Minimum humidity 7-15 percent Saturday afternoon 
  andslightly higher Sunday afternoon. Humidity will recovery 
  to greater than 15 percent Saturday night.

* IMPACTS...any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
113 
WWUS85 KVEF 242315
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
415 PM PDT Sat Apr 24 2021

AZZ101-102-CAZ229-NVZ461>466-251200-
/O.CON.KVEF.FW.W.0006.000000T0000Z-210426T0300Z/
Lake Mead NRA/Colorado River-AZ side-
Northwest Deserts/Northwest Plateau-Lower Colorado River Valley-
Lincoln County/Ely Dispatch-Nye County Deserts/Las Vegas Dispatch-
Sheep Range-Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
Lake Mead NRA/Colorado River-NV side-
415 PM PDT Sat Apr 24 2021 /415 PM MST Sat Apr 24 2021/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM PDT /8 PM MST/
SUNDAY FOR STRONG WINDS AND LOW HUMIDITY FOR SOUTHERN NEVADA AND
NORTHWEST ARIZONA...

* AFFECTED AREA...In Arizona...Fire weather zones 101 and 102. In
  California...Fire weather zone 229. In Nevada...Fire weather 
  zones 461, 462, 463, 464, 465, and 466. 

* TIMING...Through Sunday evening.

* WIND...South-southwest 15-30 mph with gusts to 40 mph into this
  evening. Local gusts over 50 mph possible. Winds will not be as
  strong overnight but will remain gusty.

* HUMIDITY...Minimum humidity 7-15 percent but will be slightly 
  higher Sunday. Humidity will recovery to greater than 15 percent
  tonight.

* IMPACTS...any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
125 
WWUS85 KVEF 251155
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
455 AM PDT Sun Apr 25 2021

AZZ101-102-CAZ229-NVZ461>466-260300-
/O.CON.KVEF.FW.W.0006.000000T0000Z-210426T0300Z/
Lake Mead NRA/Colorado River-AZ side-
Northwest Deserts/Northwest Plateau-Lower Colorado River Valley-
Lincoln County/Ely Dispatch-Nye County Deserts/Las Vegas Dispatch-
Sheep Range-Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
Lake Mead NRA/Colorado River-NV side-
455 AM PDT Sun Apr 25 2021 /455 AM MST Sun Apr 25 2021/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM THIS EVENING FOR
STRONG WINDS AND LOW HUMIDITY FOR SOUTHERN NEVADA AND NORTHWEST 
ARIZONA...

* AFFECTED AREA...In Arizona...Fire weather zones 101 and 102. In
  California...Fire weather zone 229. In Nevada...Fire weather 
  zones 461, 462, 463, 464, 465, and 466. 

* TIMING...Through this evening.

* WIND...Winds will increase this morning and become south-
  southwest 15-30 mph with gusts to 40 mph which will continue
  into this evening. Local gusts over 50 mph possible. 
 
* HUMIDITY...Minimum humidity 8-15 percent. 
 
* IMPACTS...any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now...or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$


weather.gov/lasvegas
641 
WWUS85 KVEF 260233
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
733 PM PDT Sun Apr 25 2021

AZZ101-102-CAZ229-NVZ461>466-260345-
/O.EXP.KVEF.FW.W.0006.000000T0000Z-210426T0300Z/
Lake Mead NRA/Colorado River-AZ side-
Northwest Deserts/Northwest Plateau-Lower Colorado River Valley-
Lincoln County/Ely Dispatch-Nye County Deserts/Las Vegas Dispatch-
Sheep Range-Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
Lake Mead NRA/Colorado River-NV side-
733 PM PDT Sun Apr 25 2021 /733 PM MST Sun Apr 25 2021/

...RED FLAG WARNING WILL EXPIRE AT 8 PM PDT /8 PM MST/ THIS
EVENING FOR STRONG WINDS AND LOW HUMIDITY FOR SOUTHERN NEVADA AND
NORTHWEST ARIZONA...

Relative humidity values have been slowly increasing and the wind
speeds have begun to trend lower in most locations. The red flag 
warning will be allowed to expire at 8 pm. However, gusty 
southwest winds will continue for the remainder of the evening 
hours before diminishing further overnight. 

$$


weather.gov/lasvegas

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 23, 3:15 AM MSTWind AdvisoryVEFMohave3 days

Nearby

Red Flag Warnings in Nevada, 2021Red Flag Warnings in Arizona, 2021Red 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.