Alert archive / Nevada / Red Flag Warnings in 2021

Red Flag Warning 22, NWS Las Vegas, NV

September 12, 2021Clark County, Lincoln County, Nye County, Nevada

NWS Las Vegas, NV issued this red flag warning at Sep 12, 2021, 2:25 PM PDT for Clark County, Lincoln County, Nye County, Nevada. It took effect at Sep 13, 2021, 11:00 AM PDT. It was in force for 9 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 12, 2021, 2:25 PM PDT (21:25 UTC)
In effect from
Sep 13, 2021, 11:00 AM PDT
Expired
Sep 13, 2021, 8:00 PM PDT
In force
9 hr
Issued by
NWS Las Vegas, NV

Counties Clark County, NV, Lincoln County, NV, Nye County, NV

The radar

The Las Vegas radar (KESX), 185 km from the middle of the area, began a volume at 21:24 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

Las Vegas, NV (KVEF), launched 12:00Z, 9.4 hours before the alert went out and 103 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 2021-09-12Temperature 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 2021-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
3258 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
-32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

792 
WWUS85 KVEF 122125
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
225 PM PDT Sun Sep 12 2021

NVZ464-465-131000-
/O.NEW.KVEF.FW.W.0022.210913T1800Z-210914T0300Z/
Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
225 PM PDT Sun Sep 12 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM PDT MONDAY FOR
STRONG WINDS AND LOW HUMIDITY FOR MUCH OF CLARK COUNTY IN FIRE
WEATHER ZONES 464 AND 465...

The National Weather Service in Las Vegas has issued a Red Flag
Warning, which is in effect from 11 AM to 8 PM PDT Monday. 

* AFFECTED AREA...In Nevada...Fire Weather Zones 464 and 465.

* TIMING...Monday. Relative humidities will decline rapidly after
  sunrise, with breezy winds picking up late-morning and peaking 
  in the afternoon before falling off after sunset.

* WIND...South to southwest winds 20 to 25 mph with gusts 30 to 35
  mph.

* HUMIDITY...Minimum afternoon values of 5 to 8 percent; maximum
  overnight values of 12 to 18 percent Monday night into Tuesday
  morning.

* 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
2 follow-up statements
904 
WWUS85 KVEF 130911
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
211 AM PDT Mon Sep 13 2021

NVZ464-465-140300-
/O.CON.KVEF.FW.W.0022.210913T1800Z-210914T0300Z/
Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
211 AM PDT Mon Sep 13 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM PDT THIS EVENING FOR STRONG WINDS AND LOW HUMIDITY FOR MUCH
OF CLARK COUNTY IN FIRE WEATHER ZONES 464 AND 465...

* AFFECTED AREA...In Nevada...Fire Weather Zones 464 and 465.

* TIMING...Winds will pick up late this morning and peak in the 
  afternoon before falling off after sunset. 

* WIND...South to southwest winds 20 to 25 mph with gusts 30 to
  35 mph. 

* HUMIDITY...Minimum afternoon values of 5 to 8 percent recovering
  only to 12 to 18 percent tonight into Tuesday morning.

* IMPACTS...A combination of strong winds...low relative
  humidity...and warm temperatures can contribute to extreme fire
  behavior. Any fires that develop will likely spread rapidly. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heed all fire restrictions. Outdoor burning is not recommended.

&&

$$


weather.gov/lasvegas
985 
WWUS85 KVEF 140241
RFWVEF

URGENT - FIRE WEATHER MESSAGE
National Weather Service Las Vegas NV
741 PM PDT Mon Sep 13 2021

NVZ464-465-140345-
/O.EXP.KVEF.FW.W.0022.000000T0000Z-210914T0300Z/
Spring Mountains-
Clark and SW Lincoln County Deserts/Las Vegas Dispatch-
741 PM PDT Mon Sep 13 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM PDT THIS EVENING FOR
STRONG WINDS AND LOW HUMIDITY FOR MUCH OF CLARK COUNTY IN FIRE
WEATHER ZONES 464 AND 465...

Although humidity levels will remain low, wind speeds have begun
to decrease and are forecast to be weaker on Tuesday. The Red Flag
Warning will be allowed to expire at 8 pm.

$$


weather.gov/lasvegas

Nearby

Red 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.