Strong southwest flow ahead of a deepening, nearly stationary, upper-level low in the Great Basin generated high wind and boosted temperatures to well above normal. Wind speeds increased rapidly during the late morning and continued into the early afternoon hours.
Every event with a place to put it; 4 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.
Strong southwest flow ahead of a deepening, nearly stationary, upper-level low in the Great Basin generated high wind and boosted temperatures to well above normal. Wind speeds increased rapidly during the late morning and continued into the early afternoon hours. The strongest wind was at the Fales Rock RAWS in rural Natrona County where a gust of 68 mph was registered. Other peak speeds at Lander, Hiland, and across eastern Sweetwater County hovered right around 60 mph.
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 Nov 3, 1:56 AM MST, 8 hours 19 minutes earlier.
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
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 158 AM MST TUE NOV 3 2015 WYZ001>020-022>030-041200- YELLOWSTONE NATIONAL PARK-ABSAROKA MOUNTAINS-CODY FOOTHILLS- NORTH BIG HORN BASIN-SOUTHWEST BIG HORN BASIN- SOUTHEAST BIG HORN 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- 158 AM MST TUE NOV 3 2015 ...WINTER WEATHER ADVISORY FOR THE MOUNTAINS OF NORTHWEST WYOMING THROUGH THIS AFTERNOON... ...HIGH WIND WARNING FOR PORTIONS OF CENTRAL WYOMING LATE THIS MORNING THROUGH EARLY EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT PERIODS SNOWFALL OCCURRING ABOVE 7500 FEET IN THE WESTERN MOUNTAINS. SIGNIFICANT SNOW ACCUMULATION IN THE NORTHWEST MOUNTAINS. PLEASE SEE THE WINTER WEATHER ADVISORY FOR MORE DETAILS. VERY STRONG SOUTH WIND BETWEEN ROCK SPRINGS...LANDER AND OVER TO CASPER FROM LATE THIS MORNING THROUGH THIS EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY WEDNESDAY...ISOLATED TO SCATTERED LIGHT SNOW SHOWERS POSSIBLE...DECREASING IN COVERAGE OVERNIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOW AMOUNTS AND STRONG WIND GUSTS OVER 50 MPH. THANK YOU.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 600 AM MST TUE NOV 3 2015 WYZ003-004-031530- CODY FOOTHILLS-NORTH BIG HORN BASIN- INCLUDING THE CITIES OF...CODY...MEETEETSE...POWELL...LOVELL... GREYBULL...BASIN 600 AM MST TUE NOV 3 2015 PATCHY FOG WILL BE ENCOUNTERED ACROSS THE BIG HORN BASIN THIS MORNING. VISIBILITY IN FOG WILL BE REDUCED TO UNDER A QUARTER MILE. WHEN FOG IS ENCOUNTERED...SLOW DOWN AND USE YOUR LOW BEAMS. WYZ013-023-025-031530- JACKSON HOLE-STAR VALLEY-UPPER GREEN RIVER BASIN FOOTHILLS- INCLUDING THE CITIES OF...JACKSON...AFTON...ALPINE... STAR VALLEY RANCH...THAYNE...PINEDALE 600 AM MST TUE NOV 3 2015 IN ADDITION TO SOME RAIN SHOWERS IN THE VALLEYS THIS MORNING...PATCHY FOG WILL BE ENCOUNTERED. VISIBILITY IN FOG WILL BE REDUCED TO UNDER A QUARTER MILE. WHEN FOG IS ENCOUNTERED...SLOW DOWN AND USE YOUR LOW BEAMS. 21
The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
A wind gust of 61 mph was recorded at Tipton. Other strong wind gusts included 60 mph at Continental Divide and 59 mph at the Rock Springs airport.
The wind sensor at Hiland recorded wind gusts of 58 mph.
The RAWS site at Fales Rock recorded several wind gusts past 58 mph including a maximum of 68 mph. A wind gust of 60 mph was recorded at Camp Creek.
The ASOS at Hunt Field in Lander recorded a wind gust to 59 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2015Every state in 2015This day in weather historyWarnings in Wyoming, November 2015
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: 604695, 604697, 604696, 604698.