Alert archive / Wyoming / Red Flag Warnings in 2021

Red Flag Warning 29, NWS Riverton, WY

November 26, 2021Natrona County, Wyoming

NWS Riverton, WY issued this red flag warning at Nov 26, 2021, 12:49 PM MST for Natrona County, Wyoming. It was in force for 4 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: Nov 26, 2021, 12:49 PM MST (19:49 UTC)
Expired: Nov 26, 2021, 5:00 PM MST
In force: 4 hr
Issued by: NWS Riverton, WY

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 137 km from the middle of the area, began a volume at 19:53 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

Riverton, WY (KRIW), launched 12:00Z, 7.8 hours before the alert went out and 131 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2301 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 129 m²/s²
0-3 km storm-relative helicity: 183 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

545 
WWUS85 KRIW 261949
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
1249 PM MST Fri Nov 26 2021

WYZ280-270000-
/O.NEW.KRIW.FW.W.0029.211126T1949Z-211127T0000Z/
Natrona County/Casper BLM-
1249 PM MST Fri Nov 26 2021

...RED FLAG WARNING IN EFFECT UNTIL 5 PM MST THIS AFTERNOON...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect until 5 PM MST this afternoon.

* IMPACTS: Low Humidities and Strong Gusty Winds will create
  erratic fire behavior with any new fire starts. 

* AFFECTED AREA: 
 In Central WY...Southern and western portions of Fire Weather Zone
 280.

* COUNTIES AFFECTED: 
  In Central WY...Natrona.

* WIND: Southwest 15 to 25 mph with gusts up to 35 mph.

* HUMIDITY: 12 to 16 percent.

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.

&&

$$

21

1 follow-up statement

814 
WWUS85 KRIW 262355
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
455 PM MST Fri Nov 26 2021

WYZ280-270100-
/O.EXP.KRIW.FW.W.0029.000000T0000Z-211127T0000Z/
Natrona County/Casper BLM-
455 PM MST Fri Nov 26 2021

...RED FLAG WARNING WILL EXPIRE AT 5 PM MST THIS EVENING...

Winds have begun to decrease throughout most of the region, and
cooling temperatures after sunset will quickly increase relative 
humidity; therefore, critical fire weather conditions are no longer
likely.

$$

http://weather.gov/riverton

Nearby

Red Flag Warnings in Wyoming, 2021 Every 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.