Alert archive / Wyoming / Red Flag Warnings in 2021
Red Flag Warning 25, NWS Riverton, WY
NWS Riverton, WY issued this red flag warning at Sep 27, 2021, 1:37 PM MDT for 7 counties in Wyoming. It took effect at Sep 28, 2021, 12:00 PM MDT. It was in force for 6 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 27, 2021, 1:37 PM MDT (19:37 UTC)
- In effect from
- Sep 28, 2021, 12:00 PM MDT
- Expired
- Sep 28, 2021, 6:00 PM MDT
- In force
- 6 hr
- Issued by
- NWS Riverton, WY
Counties Big Horn County, WY, Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Natrona County, WY, Park County, WY, Washakie County, WY
The radar
The Riverton/Lander radar (KRIW), 93 km from the middle of the area, began a volume at 19:38 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
Riverton, WY (KRIW), launched 12:00Z, 7.6 hours before the alert went out and 90 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3716 m above ground
- 0-6 km bulk shear
- 6 kt
- 0-1 km storm-relative helicity
- 3 m²/s²
- 0-3 km storm-relative helicity
- -14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
571
WWUS85 KRIW 271937
RFWRIW
URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
137 PM MDT Mon Sep 27 2021
WYZ275-280>282-285-281200-
/O.UPG.KRIW.FW.A.0015.210928T1700Z-210929T0000Z/
/O.NEW.KRIW.FW.W.0025.210928T1800Z-210929T0000Z/
North Big Horn Basin/Worland BLM-Natrona County/Casper BLM-
Johnson County/Casper BLM-South Big Horn Basin/Worland BLM-
South Bighorn Mountains-
137 PM MDT Mon Sep 27 2021
...RED FLAG WARNING IN EFFECT FROM NOON TO 6 PM MDT TUESDAY...
The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect from noon to 6 PM MDT Tuesday. the
Fire Weather Watch is no longer in effect.
* IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and
Strong Gusty Winds will create erratic fire behavior and new
fire starts.
* AFFECTED AREA:
In Central WY Fire Zones...280...285.
In North Central WY Fire Zones...275...281...282.
* COUNTIES AFFECTED:
In Central WY...Fremont...Natrona.
In North Central WY...Big Horn...Hot Springs...Johnson...Park
Washakie.
* WIND: South 10 to 20 mph with gusts up to 30 mph.
* HUMIDITY: 12 to 15 percent.
* TEMPERATURES: Highs in the lower to middle 80s.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Fire Weather Watch means that critical fire weather conditions
may occur. Listen for later forecasts and possible Red Flag
Warnings.
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.
&&
$$
http://weather.gov/riverton3 follow-up statements
752
WWUS85 KRIW 280811
RFWRIW
URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
211 AM MDT Tue Sep 28 2021
WYZ275-280>282-285-290000-
/O.CON.KRIW.FW.W.0025.210928T1800Z-210929T0000Z/
North Big Horn Basin/Worland BLM-Natrona County/Casper BLM-
Johnson County/Casper BLM-South Big Horn Basin/Worland BLM-
South Bighorn Mountains-
211 AM MDT Tue Sep 28 2021
...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 6 PM MDT
THIS EVENING...
* IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and
Gusty Wind will create erratic fire behavior if any new fires
start.
* AFFECTED AREA:
In Central WY Fire Zones...280...285.
In North Central WY Fire Zones...275...281...282.
* COUNTIES AFFECTED:
In Central WY...Fremont...Natrona.
In North Central WY...Big Horn...Hot Springs...Johnson...Park
Washakie.
* WIND: South 15 to 20 mph with gusts 25 to 30 mph.
* HUMIDITY: 12 to 15 percent.
* TEMPERATURES: Highs in the lower to mid 80s.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.
&&
$$
http://weather.gov/riverton683
WWUS85 KRIW 281848
RFWRIW
URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
1248 PM MDT Tue Sep 28 2021
WYZ275-280>282-285-290000-
/O.CON.KRIW.FW.W.0025.000000T0000Z-210929T0000Z/
North Big Horn Basin/Worland BLM-Natrona County/Casper BLM-
Johnson County/Casper BLM-South Big Horn Basin/Worland BLM-
South Bighorn Mountains-
1248 PM MDT Tue Sep 28 2021
...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...
* IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and
Strong Gusty Winds will create erratic fire behavior and new
fire starts.
* AFFECTED AREA:
In Central WY Fire Zones...280...285.
In North Central WY Fire Zones...275...281...282.
* COUNTIES AFFECTED:
In Central WY...Fremont...Natrona.
In North Central WY...Big Horn...Hot Springs...Johnson...Park
Washakie.
* WIND: South to southwest 15 to 20 mph with gusts up to 30 mph.
* HUMIDITY: 12 to 15 percent.
* TEMPERATURES: Highs in the lower to middle 80s.
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.
&&
$$
http://weather.gov/riverton920 WWUS85 KRIW 282339 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 539 PM MDT Tue Sep 28 2021 WYZ275-280>282-285-290045- /O.EXP.KRIW.FW.W.0025.000000T0000Z-210929T0000Z/ North Big Horn Basin/Worland BLM-Natrona County/Casper BLM- Johnson County/Casper BLM-South Big Horn Basin/Worland BLM- South Bighorn Mountains- 539 PM MDT Tue Sep 28 2021 ...RED FLAG WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING... Humidity has begun to rise and temperatures have begun to drop. As a result, the Red Flag Warning will be allowed to expire. $$ http://weather.gov/riverton
The office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 27, 2:05 AM MDT | Fire Weather Watch | RIW | Big Horn, Fremont, Hot Springs, Johnson, Natrona, Park and 1 more | 12 hr |
Nearby
Red Flag Warnings in Wyoming, 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.