A large thunderstorm developed over the east slope of the central Bighorn Range and moved northeast across Johnson County. The storm generated strong outflow wind as it crossed Interstate 90 between Buffalo and the Campbell County line.
Every event with a place to put it. 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.
A large thunderstorm developed over the east slope of the central Bighorn Range and moved northeast across Johnson County. The storm generated strong outflow wind as it crossed Interstate 90 between Buffalo and the Campbell County line. Wind gusts reached 68 mph at a sensor along the interstate.
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 Jul 17, 1:05 PM MST, 5 hours 35 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 205 PM MDT SUN JUL 17 2016 .SHORT TERM...Tonight Through Monday Rather dry west southwest flow aloft will be over the area through Monday with very warm to hot temperatures. Isolated afternoon and evening showers and thunderstorms will be possible mainly over the mountains this evening and again on Monday. Gusty southwest winds will increase over and near the east slopes of the mountains Monday afternoon. .LONG TERM...Monday night Through Sunday Rather dry west southwest flow aloft will be over the area through the weekend with very warm to hot temperatures and low relative humidity. Isolated afternoon and evening showers and thunderstorms will be possible mainly over the mountains monday evening and again on Tuesday. Then the convection is expected to be limited to the extreme south over sweetwater county. Gusty southwest winds will increase over and near the east slopes of the mountains. && .AVIATION.../00Z ISSUANCE/ Showers and thunderstorms will be found across much of central and western Wyoming through around 04z this evening. Gusty wind and small hail will be possible, with associated periods of MVFR conditions and mountain obscurations. By 06z, mainly mountain shower activity is expected. This activity will linger through 12z Monday, with widespread VFR conditions then expected. Wind will start to increase after 16z with periods of gusty wind expected by 20z for many terminals. Any shower development is expected to be over the northern mountains after 20z and could result in local mountain obscurations. Minimal impacts from these storms are anticipated at area terminals, though nearby storms may result in periods of breezy and erratic wind at KCOD. && .FIRE WEATHER... Rather dry west southwest flow aloft will be over the area through the week with very warm to hot temperatures and low relative humidity. Isolated afternoon and evening showers and thunderstorms will be possible mainly over the higher mountains this evening and again on Monday. Gusty southwest winds will increase over and near the east slopes of the mountains Monday afternoon combining with relative humidity of 10 to 15 percent in the lower elevations. && .RIW Watches/Warnings/Advisories... Fire Weather Watch from Monday afternoon through Monday evening for WYZ280-300. && SHORT TERM...C.Baker LONG TERM...C.Baker AVIATION...Branham FIRE WEATHER...C.Baker
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 330 AM MDT SUN JUL 17 2016 WYZ001>020-022>030-181200- 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- 330 AM MDT SUN JUL 17 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT ELEVATED FIRE DANGER ACROSS MUCH OF THE LOWER ELEVATIONS EAST OF THE DIVIDE. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS OVER THE REGION. SOME STORMS WILL HAVE SMALL HAIL AND GUSTY OUTFLOW WINDS TO 45 MPH. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY MONDAY...ISOLATED THUNDERSTORMS POSSIBLE ACROSS MAINLY THE ABSAROKA AND BIGHORN MOUNTAINS. TUESDAY...ISOLATED TO WIDELY SCATTERED AFTERNOON AND EVENING THUNDERSTORMS IN THE SOUTH AND CASPER MOUNTAIN AREA. GUSTY WIND AND LIGHTNING WILL BE THE MAIN THREATS. WEDNESDAY...ISOLATED AFTERNOON AND EVENING THUNDERSTORMS IN THE SOUTH. GUSTY WIND AND LIGHTNING ARE THE MAIN THREATS. THURSDAY THROUGH SATURDAY...ISOLATED AFTERNOON AND EVENING THUNDERSTORMS. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE URGED TO REPORT STRONG WIND GUSTS OVER 40 MPH. THANK YOU.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 545 PM MDT SUN JUL 17 2016 WYZ004-008-180030- BIGHORN MOUNTAINS WEST-NORTH BIG HORN BASIN- 545 PM MDT SUN JUL 17 2016 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN BIG HORN COUNTY UNTIL 630 PM MDT... AT 543 PM MDT...DOPPLER RADAR WAS TRACKING A THUNDERSTORM NEAR OTTO...WHICH IS 14 MILES WEST OF BASIN...MOVING NORTHEAST AT 35 MPH. OTHER SHOWERS...PRODUCING LITTLE RAIN...WERE FOUND ACROSS THE SOUTH HALF OF BIG HORN COUNTY. WIND GUSTS OF 40 TO 50 MPH WILL BE POSSIBLE THIS THUNDERSTORM AND WITH THE WEAKER SHOWERS. THE THUNDERSTORM WILL BE NEAR GREYBULL AROUND 610 PM MDT. OTHER LOCATIONS IMPACTED BY THE GUSTY WIND INCLUDE BURLINGTON... BASIN...MANDERSON...AND EVENTUALLY SHELL. LAT...LON 4417 10824 4450 10855 4479 10796 4417 10730 TIME...MOT...LOC 2343Z 233DEG 29KT 4439 10834 JONES
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
625 PM MDT SUN JUL 17 2016
WYZ004-006-008>011-180115-
SOUTHEAST BIG HORN BASIN-BIGHORN MOUNTAINS SOUTHEAST-BIGHORN
MOUNTAINS WEST-NORTHEAST JOHNSON COUNTY-SOUTHEAST JOHNSON
COUNTY-NORTH BIG HORN BASIN-
625 PM MDT SUN JUL 17 2016
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN WASHAKIE...
SOUTHEASTERN BIG HORN AND WESTERN JOHNSON COUNTIES UNTIL 715 PM
MDT...
AT 624 PM MDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 7 MILES NORTHEAST OF
GREYBULL TO NEAR BIG TRAILS...AND MOVING EAST AT 45 MPH.
WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THESE STORMS.
STRONG THUNDERSTORMS WILL BE NEAR...
BIG TRAILS AROUND 630 PM MDT.
SHELL AROUND 635 PM MDT.
SHELL CANYON AROUND 645 PM MDT.
SHELL FALLS AROUND 650 PM MDT.
MAYOWORTH AROUND 705 PM MDT.
OTHER LOCATIONS IMPACTED BY THESE STORMS INCLUDE MEDICINE LODGE LAKE
CAMPGROUND...AND TENSLEEP CAMPGROUND.
THIS INCLUDES INTERSTATE 25 BETWEEN MILE MARKERS 257 AND 288.
LAT...LON 4378 10639 4365 10737 4465 10806 4474 10775
4472 10775 4471 10768 4468 10767 4470 10762
4466 10752 4463 10752 4464 10750 4461 10747
4460 10739 4456 10737 4456 10691
TIME...MOT...LOC 0024Z 254DEG 40KT 4459 10800 4372 10741
BRAUNSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
633 PM MDT SUN JUL 17 2016
WYZ002>004-180115-
ABSAROKA MOUNTAINS-CODY FOOTHILLS-NORTH BIG HORN BASIN-
633 PM MDT SUN JUL 17 2016
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN PARK COUNTY UNTIL
715 PM MDT...
AT 629 PM MDT...DOPPLER RADAR WAS TRACKING AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS WEST OF CODY OVER THE ABSAROKA MOUNTAINS...
MOVING NORTHEAST AT 35 MPH.
WIND GUSTS OF 40 TO 50 MPH WILL BE POSSIBLE WITH THESE SHOWERS AND
STORMS.
THESE SHOWERS AND STORMS WILL BE NEAR...
BUFFALO BILL STATE PARK AROUND 645 PM MDT.
CODY AROUND 700 PM MDT.
POWELL AROUND 715 PM MDT.
LAT...LON 4459 10859 4427 10927 4462 10990 4467 10987
4470 10983 4473 10984 4489 10976 4498 10885
TIME...MOT...LOC 0029Z 233DEG 30KT 4448 10939
JONESSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 647 PM MDT SUN JUL 17 2016 WYZ002-015>017-180145- ABSAROKA MOUNTAINS-WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-UPPER WIND RIVER BASIN- 647 PM MDT SUN JUL 17 2016 ...STRONG WIND GUSTS FROM SHOWERS AND STORMS WILL AFFECT NORTHWESTERN FREMONT COUNTY... AT 644 PM MDT...STRONG WIND GUSTS TO 55 MPH WERE LOCATED NEAR DUBOIS...MOVING EAST NORTHEAST THROUGH THE WEST END OF FREMONT COUNTY. WIND GUSTS OF 45 TO 55 MPH...WITH LOCALIZED HIGHER GUSTS...ARE POSSIBLE WITH THIS SHOWER. LOCATIONS IMPACTED INCLUDE... CROWHEART...BURRIS...MAVERIK SPRING DOME FIELD... AND LONGHORN RANCH LODGE AND RV RESORT. LAT...LON 4319 10920 4351 10960 4364 10934 4349 10869 TIME...MOT...LOC 0044Z 240DEG 49KT 4359 10940 BRAUN
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
653 PM MDT SUN JUL 17 2016
WYZ009>011-180145-
BIGHORN MOUNTAINS SOUTHEAST-NORTHEAST JOHNSON COUNTY-SOUTHEAST
JOHNSON COUNTY-
653 PM MDT SUN JUL 17 2016
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN JOHNSON COUNTY UNTIL
745 PM MDT...
AT 652 PM MDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 9 MILES SOUTHEAST OF CLOUD
PEAK TO 14 MILES NORTHEAST OF DULLKNIFE RESERVOIR TO MAYOWORTH...AND
MOVING EAST AT 55 MPH.
NICKEL SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH
THESE STORMS.
STRONG THUNDERSTORMS WILL BE NEAR...
LAKE DE SMET AROUND 705 PM MDT.
BUFFALO AROUND 710 PM MDT.
FORT RENO HISTORICAL SITE AROUND 720 PM MDT.
POWDER RIVER REST AREA AROUND 725 PM MDT.
OTHER LOCATIONS IMPACTED BY THESE STORMS INCLUDE BUFFALO GOLF
COURSE...TA GUEST RANCH AND JOHNSON COUNTY FAIRGROUNDS.
THIS INCLUDES THE FOLLOWING HIGHWAYS...
INTERSTATE 25 BETWEEN MILE MARKERS 257 AND 299.
INTERSTATE 90 BETWEEN MILE MARKERS 48 AND 95.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
&&
LAT...LON 4376 10602 4374 10677 4410 10680 4437 10706
4456 10660 4456 10601 4382 10601
TIME...MOT...LOC 0052Z 256DEG 50KT 4432 10700 4410 10679 4382 10677
BRAUNSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
729 PM MDT SUN JUL 17 2016
WYZ010-011-180215-
NORTHEAST JOHNSON COUNTY-SOUTHEAST JOHNSON COUNTY-
729 PM MDT SUN JUL 17 2016
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN JOHNSON COUNTY UNTIL
815 PM MDT...
AT 727 PM MDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 7 MILES EAST OF BUFFALO TO
15 MILES SOUTHWEST OF POWDER RIVER REST AREA TO NEAR FORT RENO
HISTORICAL SITE...AND MOVING NORTHEAST AT 35 MPH.
DIME TO NICKLE SIZE HAIL AND WIND GUSTS 45 TO 55 MPH...WITH
LOCALLY HIGHER GUSTS POSSIBLE...WILL BE POSSIBLE WITH THESE STORMS.
STRONG THUNDERSTORMS WILL BE NEAR...
POWDER RIVER REST AREA AROUND 755 PM MDT.
OTHER LOCATIONS IMPACTED BY THESE STORMS INCLUDE TWIN CREEKS
CAMPGROUND...JOHNSON COUNTY FAIRGROUNDS...INDIAN CAMPGROUND AND
JOHNSON COUNTY LIBRARY.
THIS INCLUDES THE FOLLOWING HIGHWAYS...
INTERSTATE 25 BETWEEN MILE MARKERS 275 AND 299.
INTERSTATE 90 BETWEEN MILE MARKERS 57 AND 95.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
&&
LAT...LON 4382 10640 4403 10669 4437 10670 4456 10627
4456 10601 4387 10601
TIME...MOT...LOC 0127Z 230DEG 32KT 4432 10656 4411 10645 4390 10628
BRAUNThe Riverton/Lander radar (KRIW), 219 km away, was scanning. The volume nearest the first event began at 01:41 UTC.
1 thunderstorm wind. Local standard time, as filed.
Wind gusts of 65 and 68 mph were measured along Interstate 90 east of Buffalo as a thunderstorm moved north across the road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2016Every state in 2016This day in weather historyWarnings in Wyoming, July 2016
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: 654066.