Wyoming, 2020Wildfire in Wyoming, September 17 to 30, 2020
September 17 to 30, 2020 · NWS CYS · 1 event in 1 county or zone
The Mullen Fire began on Thursday, September 17th in dense timber both litter and understory in the Medicine Bow National Forest under ideal fire weather conditions of low humidity, gusty winds, and critical fuel levels. Plenty of downed trees and recent beetle kill made the area a tinder box as several days through the end of September met Red Flag Warning conditions for critical fire weather…
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
Open the live radar over this ground
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The Mullen Fire began on Thursday, September 17th in dense timber both litter and understory in the Medicine Bow National Forest under ideal fire weather conditions of low humidity, gusty winds, and critical fuel levels. Plenty of downed trees and recent beetle kill made the area a tinder box as several days through the end of September met Red Flag Warning conditions for critical fire weather and saw extreme growth for the fire to grow over 106,000 acres by the end of September. For communities of lower Keystone, Lake Creek and Foxborough, twenty-nine dwellings and thirty-one outbuildings were lost to the fire. On the last day of September extreme fire growth spread the fire down into Colorado. The fire continued to burn into October and November. Sixty-six total structures including homes and outbuildings were destroyed from the wildfire. Overall fire fighting cost $42.4 million.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Cheyenne, WY wrote its last area forecast discussion before the first event at Sep 16, 10:22 PM MST, 1 hour 38 minutes earlier.
Area forecast discussion, Sep 16, 10:22 PM MST, 1 hour 38 minutes before
Area Forecast Discussion...CORRECTED
National Weather Service Cheyenne WY
1122 PM MDT Wed Sep 16 2020
.UPDATE...
Issued at 745 PM MDT Wed Sep 16 2020
AQA through the overnight period still looks par for the course as
smoke/haze conditions continue to keep reduced visibility
observations occurring throughout the CWA and reduced air quality
overall. Stationary frontal boundary is draped NW to SE across
the western forecast zones down into the central Colorado region.
Overnight lows look to be a few degrees cooler compared to last
night across the forecast region, mainly 40-50 degrees, with the
warmest overnight lows occurring over the western Nebraska
Panhandle and in lower elevations along the North Platte River
Valley. Expect dry conditions to continue overnight also as the
upper level ridge axis slowly propagates towards the area
overnight and into Thursday.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 230 PM MDT Wed Sep 16 2020
Haze continues to build into our region. A high pressure system
will move into northern Wyoming tomorrow morning which will bring
drier conditions to our mid levels. No precipitation is expected
for the rest of the week. High temperatures will lower into the
upper 70s to mid 80s with light winds. Wind gust will range from
15kts to 10kts for the next few days.
.LONG TERM...(Saturday through Wednesday)
Issued at 230 PM MDT Wed Sep 16 2020
Low pressure moves into western Montana Saturday morning with
ridge axis shifting east into the Dakotas and central nebraska.
Southwest winds increase with GFS 700mb winds approaching 35-40kts
across Carbon County. Looks like a great Red Flag day across much
of the CWA and will likely issue a Fire Weather Watch tomorrow
afternoon if the night crew doesn't issue tonight.
Associated cold front moves through Saturday night into Sunday
with 700mb temperatures falling to single digits behind the front.
Did undercut guidance...but will likely need to cut more as we get
closer to the event.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday evening)
Issued at 1110 PM MDT Wed Sep 16 2020
Visibilities will be reduced to MVFR from haze and smoke at all but
the KRWL terminal through Thursday morning. Light/variable winds
will shift to the north and northeast Thursday morning except at
KRWL where light westerly winds will prevail. Winds could gust near
20 kt at KAIA and KSNY after 18Z Thursday.
&&
.FIRE WEATHER...
Issued at 230 PM MDT Wed Sep 16 2020
Dry...warm and smoky conditions continue across southeast Wyoming and
Nebraska Panhandle as high pressure remains over the Rockies. A dry
cold front remains over the area east of the Laramie Range through
Thursday. Westerly winds return Friday night into Saturday that
could create critical fire weather conditions...especially Saturday
afternoon.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
UPDATE...BW
SHORT TERM...AW
LONG TERM...GCC
AVIATION...MAJ
FIRE WEATHER...GCC
Hazardous weather outlook, Sep 16, 3:45 AM MST, 20 hours 15 minutes before
Hazardous Weather Outlook...CORRECTED
National Weather Service Cheyenne WY
445 AM MDT Wed Sep 16 2020
WYZ103>106-109>117-170945-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte County-
Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Sierra Madre Range-
Upper North Platte River Basin-Snowy Range-Laramie Valley-
South Laramie Range-South Laramie Range Foothills-
445 AM MDT Wed Sep 16 2020
This hazardous weather outlook is for portions of south central
Wyoming and southeast Wyoming.
.DAY ONE...TODAY AND TONIGHT
Haze and areas of smoke may lower surface visibilities to five
miles at times today and tonight.
.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
Elevated to near critical fire weather conditions are expected
Thursday and Friday.
Haze will continue Thursday through Friday.
Widely scattered thunderstorms will develop Saturday afternoon and
evening. Severe weather is not expected.
.Spotter information statement...
Spotter activation will not be required.
NEZ002-003-019>021-054-055-095-096-WYZ101-102-107-108-118-119-
170945-
Dawes-Box Butte-Scotts Bluff County-Banner County-Morrill-
Kimball County-Cheyenne-North Sioux-South Sioux-
Converse County Lower Elevations-Niobrara County-
East Platte County-Goshen County-Central Laramie County-
East Laramie County-
445 AM MDT Wed Sep 16 2020
This hazardous weather outlook is for the western Nebraska
Panhandle...portions of east central Wyoming and southeast
Wyoming.
.DAY ONE...TODAY AND TONIGHT
Haze and areas of smoke may lower surface visibilities to five
miles at times today and tonight.
.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
Haze will continue Thursday through Friday.
Widely scattered thunderstorms will develop Saturday evening.
Severe weather is not expected.
.Spotter information statement...
Spotter activation will not be required.
Wildfire, Snowy Range
- When
- September 17, 12:00 AM MST to September 30, 11:59 PM MST
- Where
- Snowy Range forecast zone
- Reported by
- Park/Forest Service
- Coordinates
- 41.675, -106.327 (the zone’s center; the record gives no point)
The Mullen Fire began on Thursday, September 17th in dense timber both litter and understory in the Medicine Bow National Forest under ideal fire weather conditions of low humidity, gusty winds, and critical fuel levels. Plenty of downed trees and recent beetle kill made the area a tinder box as several days through the end of September met Red Flag Warning conditions for critical fire weather and saw extreme growth for the fire to grow over 106,000 acres by the end of September. For communities of lower Keystone, Lake Creek and Foxborough, twenty-nine dwellings and thirty-one outbuildings were lost to the fire. On the last day of September extreme fire growth spread the fire down into Colorado. The fire continued to burn into October and November. Sixty-six total structures including homes and outbuildings were destroyed from the wildfire. Overall fire fighting cost $42.4 million.
- Wildfire
- A fire burning in wildland vegetation, with its acreage and damage where known.
After NWS Directive 10-1605, the rules offices file Storm Data by.
- Flood in Washington, September 17 to 18, 2020$250 million · 1 event
- Flood and Hail in Oregon, September 17 to 18, 2020$41,000 · 50 kt wind · 22 events
- Heavy Rain in Virginia, September 17 to 18, 202050 events
- Flash Flooding and Damaging Winds in South Carolina, September 17, 2020$50,000 · 56 kt wind · 10 events
- Tornadoes in South Carolina, September 17, 2020$51,000 · EF0 · 2 events
- Tornadoes in North Carolina, September 17, 2020$35,000 · EF0 · 2 events
- Tornado and Damaging Wind in Georgia, September 17, 2020EF1 · 2 events
- Tornado and Damaging Wind in South Carolina, September 17, 2020EF1 · 2 events
- Tornadoes in North Carolina, September 17 to 18, 2020EF1 · 2 events
- Excessive Heat in Arizona, September 17, 202011 events
- Heavy Rain in North Carolina, September 17 to 18, 20209 events
- Excessive Heat in California, September 17 to 18, 20207 events
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 913924.