The Fish Creek fire continued to burn across Bridger-Teton National Forest throughout the month, leading to numerous closures of US 26 over Togwotee Pass. The Pack Creek fire was started by lightning 23 miles southeast of Moran on September 15 and spread northeastward.
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.
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 episode as NWS RIW wrote it up.
The Fish Creek fire continued to burn across Bridger-Teton National Forest throughout the month, leading to numerous closures of US 26 over Togwotee Pass. The Pack Creek fire was started by lightning 23 miles southeast of Moran on September 15 and spread northeastward. These two fires merged toward the end of the month. By September 30th, the fires had burned over 40000 acres. Please see later Storm Data for the conclusion of these two fires.
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 Riverton, WY wrote its last area forecast discussion before the first event at Aug 31, 9:11 PM MST, 2 hours 49 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Riverton WY 1011 PM MDT Sat Aug 31 2024 .KEY MESSAGES... - High pressure this last day of August is producing very clear skies, relatively light east winds, and very dry conditions. - Sunday will see the high pressure continue, with some clouds move up from the south late in the day. Elevated fire weather conditions will be seen over northeast WY Sunday afternoon due to gusty southeast winds and low humidity. - Temperatures warm a couple more degrees on Monday as winds become breezy from the southwest, and isolated thunderstorms move into western WY. - Tuesday and Wednesday will see a disturbance move through the area, bringing cooler temperatures, stronger wind, a good chance of isolated to scattered showers over western and central WY. && .DISCUSSION... Issued at 130 PM MDT Sat Aug 31 2024 High pressure continues over the northern Great Basin today, extending into Wyoming and Montana. The result is very clear skies (although there is lingering smoke from the central Idaho fires to create hazy conditions) and relatively light winds. The surface pressure gradient has shifted such that most winds this afternoon are from the east-northeast. A few places are seeing gusts in the 15-20 mph range, but pretty light overall. Models are indicating some gusty winds over the southwest foothills of the Bighorns overnight as the easterly flow pushes over the mountains into the Bighorn Basin. The ridge axis then moves eastward over Wyoming mid-day Sunday, tightening the gradient over eastern Wyoming and increasing southerly flow from southern into northeastern Wyoming. Dry conditions are expected along with slightly warmer temperatures and slightly lower humidities. The result is elevated fire weather conditions over northeast Wyoming for a potential problem with the Johnson/Sheridan/Campbell County fire areas. Have continued the Fire Weather Watch at this time due to marginal winds, and will let the next couple of model runs decide on whether a Red Flag Warning is necessary. Isolated convection is expected over northern Colorado and into the southwestern Wyoming mountains, which could produce gusty outflows into southern and central Wyoming. The ridge axis then moves eastward on Monday as a trough digs along the West Coast. Moisture will thus increase over the northern Great Basin into western Wyoming Monday afternoon, bringing isolated showers and thunderstorms. At the same time, southwest winds will increase across southern and central Wyoming. Elevated fire weather conditions are expected from South Pass into Natrona County as a result. Afternoon temperatures will increase even more in most areas to 8-10 degrees above normal. As the trough moves into Idaho on Tuesday, showers and thunderstorms will increase over western Wyoming Tuesday morning and temperatures will start to slightly cool. A weak cold front will push west to east across the area later Tuesday afternoon, bringing scattered showers and thunderstorms to areas from Sweetwater County into central and north-central Wyoming. Models are showing the low center diving southeast along the Continental Divide on Wednesday, resulting in dry, cool and gusty northwest flow for most of southwest Wyoming, and cool moist/wet conditions east of the Divide. High pressure then builds again over the Great Basin, bringing dry conditions Thursday and early Friday. Quite a bit of disagreement exists for late next week, so will defer any discussion to later shifts for more certainty. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1005 PM MDT Sat Aug 31 2024 Smoke continues to thin through 06Z across southern and western WY, however the Fish Creek Fire near KDUB has plumed out this afternoon. Localized impacts to visibility as smoke pushes westward into the northern end of the Jackson Valley and the south entrance of Yellowstone. This could gradually get pushed southward toward KJAC, but will take a wait-and-see approach for now. Otherwise, conditions will remain SKC, with light wind through 18Z. Clouds will increase across the western half of the forecast area after 18Z, moving toward the east-northeast, with FEW-SCT clouds continuing through the end of the TAF period. An isolated shower or thunderstorm cannot be ruled out as these clouds move over the mountains through the afternoon. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .FIRE WEATHER... Issued at 110 PM MDT Sat Aug 31 2024 The rest of Saturday will see high pressure over western and central WY with relatively light winds, very clear skies, and low humidities. Some east to northeast winds have developed today, and gusty (15-20 mph) winds are expected in Johnson County and around the west side of the Bighorns - not the typical wind flow pattern. The high pressure axis will move over the state on Sunday, bringing more southerly winds. At this time, enhanced wind speeds look to primarily be over northeast WY, extending into Johnson County. Combined with min RH values in the 12-15 percent range, elevated fire weather conditions look likely - thus, the Fire Weather Watch for zone 281 remains in effect Sunday afternoon through 8pm. Leaving the watch at this time to allow for a more accurate wind forecast in later model runs to decide whether to upgrade to a Red Flag Warning or to simply highlight elevated conditions. Some gusty south winds might move into zones 279, 289, 280, and 300 from the south as isolated convection develops Sunday afternoon over northern CO and parts of southeastern WY. As a low pressure system digs over WA/OR/ID on Monday, the southwest flow and moisture will increase on Monday. As winds increase east of the divide with low RH conditions, a fire weather watch will likely be needed at least over zones 289 and 280 in central WY Monday afternoon. There is some discussion as well about elevated fire weather conditions over northwest WY before the scattered storms move over the area Monday night. Suffice to say Monday to Wednesday will be a change of the weather compared to the last couple of days. && .RIW WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Sunday afternoon through Sunday evening for WYZ281. && DISCUSSION...McDonald AVIATION...LaVoie FIRE WEATHER...McDonald
Hazardous Weather Outlook National Weather Service Riverton WY 247 AM MDT Sat Aug 31 2024 WYZ001>020-022>030-011300- Yellowstone National Park-Absaroka Mountains-Cody Foothills- North Bighorn Basin-Southwest Bighorn Basin-Southeast Bighorn Basin- Owl Creek and Bridger Mountains-Bighorn Mountains West- Bighorn Mountains Southeast-Northeast Johnson County- Southeast Johnson County-Teton and Gros Ventre Mountains- Jackson Hole-Wind River Mountains West-Wind River Mountains East- Upper Wind River Basin-Wind River Basin-Lander Foothills- Green Mountains and Rattlesnake Range- Natrona County Lower Elevations-Casper Mountain-Star Valley- Salt River and Wyoming Ranges-Upper Green River Basin Foothills- Upper Green River Basin-South Lincoln County- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- 247 AM MDT Sat Aug 31 2024 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Sunday...Critical fire weather conditions are possible across portions of Johnson County Sunday afternoon due to low humidity, above normal temperatures, and gusty southerly wind. Labor Day and Tuesday...Elevated fire weather conditions possible across portions of central and southwest Wyoming. Labor Day through Thursday...A chance of afternoon thunderstorms returns to the west Labor Day. The storms become more widespread across the forecast area each afternoon Tuesday through Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
1 wildfire. Local standard time, as filed.
Please see Episode for a description.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2024Every state in 2024This day in weather historyWarnings in Wyoming, September 2024
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: 1217164.