Alert archive / Wyoming / Red Flag Warnings in 2021
Red Flag Warning 6, NWS Riverton, WY
NWS Riverton, WY issued this red flag warning at Jul 15, 2021, 3:33 PM MDT for 11 counties in Wyoming. It took effect at Jul 16, 2021, 12:00 PM MDT. It was in force for 9 hr. 2 reports 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
- Jul 15, 2021, 3:33 PM MDT (21:33 UTC)
- In effect from
- Jul 16, 2021, 12:00 PM MDT
- Expired
- Jul 16, 2021, 9:00 PM MDT
- In force
- 9 hr
- Issued by
- NWS Riverton, WY
Counties Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Lincoln County, WY, Natrona County, WY, Park County, WY, Sublette County, WY, Sweetwater County, WY, Teton County, WY, Uinta County, WY, Washakie County, WY
The radar
The Riverton/Lander radar (KRIW), 38 km from the middle of the area, began a volume at 21:36 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 16, 2:36 PM MDT | TSTM WND GST 64 | Worland, WY | |
| Jul 16, 7:49 PM MDT | TSTM WND GST 60 | Big Piney, WY |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Riverton, WY (KRIW), launched 12:00Z, 9.6 hours before the alert went out and 44 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
- 345 J/kg
- Mixed-layer CIN
- -183 J/kg
- Mixed-layer LCL
- 1860 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -31 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
697 WWUS85 KRIW 152133 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 333 PM MDT Thu Jul 15 2021 WYZ277-278-281>283-285-287-288-414>416-161200- /O.NEW.KRIW.FW.W.0006.210716T1800Z-210717T0300Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM-Johnson County/Casper BLM- South Big Horn Basin/Worland BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-East Wind River Mountains/South Shoshone NF- Salt and Wyoming Ranges/West Zone Bridger Teton NF- North Zone Bridger Teton NF and Grand Teton NP- West Wind River Mountains/East Zone Bridger Teton NF- 333 PM MDT Thu Jul 15 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT FRIDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon to 9 PM MDT Friday. * IMPACTS: Increasing Thunderstorm Activity will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...283...285...288. In North Central WY Fire Zones...281...282...287. In Northwest WY Fire Zone....415. In Southwest WY Fire Zone....277. In West Central WY Fire Zones...278...414...416. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Park...Washakie. In Southwest WY...Sweetwater...Teton...Uinta. In West Central WY...Lincoln...Sublette. * THUNDERSTORMS: Thunderstorms will develop over the area between 1 and 2 PM Friday, continuing into the evening. Lightning will be frequent with this activity. These areas have been very dry for the last several weeks. 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. && $$ http://weather.gov/riverton
3 follow-up statements
511 WWUS85 KRIW 160837 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 237 AM MDT Fri Jul 16 2021 WYZ277-278-281>283-285-287-288-414>416-170000- /O.CON.KRIW.FW.W.0006.210716T1800Z-210717T0300Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM-Johnson County/Casper BLM- South Big Horn Basin/Worland BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-East Wind River Mountains/South Shoshone NF- Salt and Wyoming Ranges/West Zone Bridger Teton NF- North Zone Bridger Teton NF and Grand Teton NP- West Wind River Mountains/East Zone Bridger Teton NF- 237 AM MDT Fri Jul 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS EVENING... * IMPACTS: Increasing Thunderstorm Activity will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...283...285...288. In North Central WY Fire Zones...281...282...287. In Northwest WY Fire Zone....415. In Southwest WY Fire Zone....277. In West Central WY Fire Zones...278...414...416. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Park...Washakie. In Southwest WY...Sweetwater...Teton...Uinta. In West Central WY...Lincoln...Sublette. * THUNDERSTORMS: Thunderstorms will develop over the area between after 12 pm, continuing into the evening. Lightning will be frequent with this activity. These areas have been very dry for the last several weeks. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
001 WWUS85 KRIW 161857 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 1257 PM MDT Fri Jul 16 2021 WYZ277-278-281>283-285-287-288-414>416-170300- /O.CON.KRIW.FW.W.0006.000000T0000Z-210717T0300Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM-Johnson County/Casper BLM- South Big Horn Basin/Worland BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-East Wind River Mountains/South Shoshone NF- Salt and Wyoming Ranges/West Zone Bridger Teton NF- North Zone Bridger Teton NF and Grand Teton NP- West Wind River Mountains/East Zone Bridger Teton NF- 1257 PM MDT Fri Jul 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING... * IMPACTS: Increasing Thunderstorm Activity will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...283...285...288. In North Central WY Fire Zones...281...282...287. In Northwest WY Fire Zone....415. In Southwest WY Fire Zone....277. In West Central WY Fire Zones...278...414...416. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Park...Washakie. In Southwest WY...Sweetwater...Teton...Uinta. In West Central WY...Lincoln...Sublette. * THUNDERSTORMS: Thunderstorms will develop over the area this afternoon, quickly ending this evening through sunset. Lightning will be frequent with this activity. These areas have been very dry for the last several weeks. 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. && $$ http://weather.gov/riverton
982 WWUS85 KRIW 170309 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 909 PM MDT Fri Jul 16 2021 WYZ277-278-281>283-285-287-288-414>416-170415- /O.EXP.KRIW.FW.W.0006.000000T0000Z-210717T0300Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM-Johnson County/Casper BLM- South Big Horn Basin/Worland BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-East Wind River Mountains/South Shoshone NF- Salt and Wyoming Ranges/West Zone Bridger Teton NF- North Zone Bridger Teton NF and Grand Teton NP- West Wind River Mountains/East Zone Bridger Teton NF- 909 PM MDT Fri Jul 16 2021 ...RED FLAG WARNING HAS EXPIRED... The Red Flag Warning for Thursday, July 16, has been allowed to expire. Isolated to scattered thunderstorms have started several new wildfires across western and central Wyoming today. Isolated thunderstorms can be expected again on Saturday, July 17, but the coverage will not be as extensive as Thursday and Friday. Thus, a red flag warning will not be issued, through elevated fire weather conditions are possible with the isolated thunderstorms. Afternoon high temperatures on Saturday will be about 2-3 degrees warmer than Friday, and afternoon minimum humidities will be about the same, as low as 12 percent in some low elevations, and 18 to 20 percent in the higher elevations. General wind will be light to breezy on Saturday, though gusty outflow could exceed 40 mph. $$ http://weather.gov/riverton
The office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 15, 1:09 PM MDT | Special Weather Statement | RIW | Sublette | 36 min |
| Jul 15, 1:17 PM MDT | Special Weather Statement | RIW | 28 min | |
| Jul 15, 1:34 PM MDT | Special Weather Statement | RIW | 26 min | |
| Jul 15, 2:00 PM MDT | Special Weather Statement | RIW | 30 min | |
| Jul 15, 2:02 PM MDT | Special Weather Statement | RIW | 28 min | |
| Jul 15, 2:02 PM MDT | Special Weather Statement | RIW | 28 min | |
| Jul 15, 2:23 PM MDT | Special Weather Statement | RIW | Fremont | 37 min |
| Jul 15, 2:26 PM MDT | Special Weather Statement | RIW | Lincoln | 34 min |
| Jul 15, 2:58 PM MDT | Special Weather Statement | RIW | Fremont | 32 min |
| Jul 15, 3:02 PM MDT | Special Weather Statement | RIW | Johnson | 28 min |
| Jul 15, 3:32 PM MDT | Special Weather Statement | RIW | Fremont | 28 min |
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.