An Alberta Clipper dropped southeast across the Dakotas and strong winds aloft mixed to the ground. Favorable northwesterly wind aloft generated high wind along the eastern slopes of the Absaroka and Bighorn mountain ranges.
Every event with a place to put it; 3 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.
An Alberta Clipper dropped southeast across the Dakotas and strong winds aloft mixed to the ground. Favorable northwesterly wind aloft generated high wind along the eastern slopes of the Absaroka and Bighorn mountain ranges. The highest wind was in the wind prone areas west of Clark where gusts up to 72 mph were recorded. High wind also occurred across northern Johnson County with a 58 mph gust measured at the Johnson County Airport near Buffalo. Farther south in Johnson County, sustained wind of up to 44 mph was clocked for more than a few hours during the afternoon.
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 Apr 5, 2:36 AM MST, 4 hours 18 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 336 AM MDT TUE APR 5 2016 .SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT ONE MORE DAY OF ACTIVE WEATHER BEFORE WE GET A BREAK FOR SOME NICE SPRING WEATHER. A COLD FRONT IS CURRENTLY CROSSING THE AREA WITH A FEW LIGHT SHOWERS. THESE SHOULD MOVE AWAY BY MORNING. HOWEVER...AN ALBERTA CLIPPER WILL DROP SOUTHWARD OUT OF CANADA AND INTO THE DAKOTAS TODAY. THE MODELS HAVE TRENDED A LITTLE FURTHER EAST TODAY AND THEREFORE THE WINDS LOOK A LITTLE LIGHTER. HOWEVER...THE EMPHASIS IS STILL ON LITTLE. THE MODELS ARE STILL SHOWING FROM 50 TO 60 KNOTS AT 700 MILLIBARS ACROSS JOHNSON COUNTY. WITH THE LOW PRESSURE PROVIDING SOME MIXING AS WELL...WE WILL UPGRADE THE WATCH TO A WARNING THIS MORNING. ELSEWHERE...ALTHOUGH HIGH WINDS ARE NOT EXPECTED...THERE COULD STILL BE SOME GUSTY WINDS SO WE WILL ISSUE AN SPS FOR THOSE LOCATIONS...AKA THE WIND RIVER BASIN...BIG HORN BASIN...NATRONA COUNTY AND EASTERN SWEETWATER COUNTY. AS FOR PRECIPITATION...THERE WILL BE SOME ACROSS THE NORTH. THE HEAVIEST WILL BE IN THE WESTERN SLOPES OF THE BIGHORN RANGE WHERE NORTHWEST FLOW IS FAVORED. HOWEVER...SINCE PRECIPITATION SHOULD NOT LAST LONG AND THERE IS NOT A LOT OF MOISTURE TO WORK WITH...AMOUNTS SHOULD REMAIN SUB ADVISORY. WIND SHOULD BEGIN TO DECREASE LATER TONIGHT AS THE PRESSURE GRADIENT LESSENS AND THE UPPER LEVEL WINDS DECREASE SOMEWHAT. PRECIPITATION SHOULD END LATE TONIGHT AS WELL. TEMPERATURES WILL AVERAGE 10 TO 15 DEGREES LOWER THAN YESTERDAY. A RIDGE OF HIGH PRESSURE WILL THEN BUILD ACROSS THE AREA FOR WEDNESDAY INTO THURSDAY AND BRING MORE SETTLED WEATHER WITH LESS WIND. THERE WILL STILL BE ENOUGH OF A PRESSURE GRADIENT FOR CONTINUED WINDY CONDITIONS ACROSS JOHNSON COUNTY ON WEDNESDAY BUT WINDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. ALL AREAS SHOULD HAVE LESS WIND THURSDAY. TEMPERATURES WILL BE ON THE UPWARD TREND INTO THURSDAY WITH SOME 70S POSSIBLE IN BIG HORN BASIN THURSDAY. .LONG TERM...FRIDAY THROUGH TUESDAY SYNOPSIS...AN UPPER RIDGE WILL BRING DRY AND MILD WEATHER ON FRIDAY. AN UPPER LOW PRESSURE SYSTEM WILL BEGIN TO SPREAD CHANCES OF SHOWERS AND A FEW THUNDERSTORM ACROSS THE SOUTH AND WEST ON SATURDAY. A CANADIAN COLD FRONT WILL DROP SOUTH EAST OF THE DIVIDE ON SUNDAY BRINGING COOLER TEMPERATURES ALONG WITH CHANCES OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS ACROSS THE AREA. COOL WEATHER WILL CONTINUE INTO MONDAY WITH MAINLY SOME LINGERING MOUNTAIN SHOWERS. DISCUSSION...MEDIUM RANGE MODELS IN BETTER AGREEMENT OVERALL WITH SPLIT FLOW OVER THE WEEKEND...WITH THE ECMWF TRENDING TOWARD THE GFS'S MORE PROGRESSIVE NORTHERN STREAM. UPPER RIDGE EXTENDS FROM THE SOUTHERN PLAINS INTO THE CANADIAN ROCKIES ON FRIDAY WITH PACIFIC TROUGH SPLITTING AS IT APPROACHES THE WEST COAST. NORTHERN STREAM SHORTWAVE RACES EAST ACROSS THE NORTHERN ROCKIES SATURDAY...OUTRUNNING THE SOUTHERN STREAM WITH CLOSED UPPER LOW DRIFTING OFF THE COAST OF SOUTHERN CALIFORNIA COAST. SOUTHERLY DIFLUENT FLOW AHEAD OF THIS UPPER LOW WILL BRING INCREASING MOISTURE AND INSTABILITY UP INTO SOUTHERN AND WESTERN WYOMING SATURDAY AFTERNOON WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED WEST OF THE DIVIDE. BREEZY TO WINDY CONDITIONS WILL DEVELOP ACROSS CENTRAL AREAS ALONG WITH VERY MILD CONDITIONS...POSSIBLY APPROACHING 80F IN THE LOWER BIGHORN BASIN. SOME HIGH BASED SHOWERS OR THUNDERSTORMS MOVING EAST OF THE DIVIDE OVER DRY BOUNDARY LAYER COULD PRODUCE SOME STRONG WIND GUSTS. NORTHERN STREAM SHORTWAVE WILL PUSH A CANADIAN COLD FRONT SOUTH ALONG THE EAST SLOPES OF THE DIVIDE ON SUNDAY...THOUGH THE DEEPER/COLDER AIR WITH THIS FRONT IS NOW EXPECTED TO STAY WELL NORTH AND EAST OF THE AREA. SOUTHERN UPPER LOW MOVING INTO THE FOUR CORNERS REGION WILL CONTINUE TO SPIN UP MOISTURE OVER THE FRONT. MODELS CONTINUE TO TARGET THE WIND RIVER RANGE TO CASPER AND SOUTHWARD WITH THE HEAVIER PRECIPITATION AMOUNTS. A RIDGE IS EXPECTED TO BRIEFLY BUILD OVER THE AREA MONDAY WITH ANOTHER PACIFIC SYSTEM POSSIBLY MOVING ACROSS THE AREA ON TUESDAY. THE OUTLOOK JUST BEYOND THIS PERIOD SHOWS A GENERALLY WET AND COOL PATTERN SETTING UP ACROSS THE WEST WEDNESDAY THROUGH FRIDAY...APRIL 13-15. && .AVIATION.../12Z ISSUANCE/ WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI ROUTES SCATTERED RAIN AND SNOW SHOWERS IN NW WY THROUGH 21Z WITH AREAS OF MVFR CONDITIONS. IN SW WY ISOLATED SHOWERS THROUGH 21Z TUE WITH VFR CONDITIONS AT THE TERMINAL SITES. A GUSTY WIND AT THE TERMINAL SITES TODAY WITH THE WIND DECREASING AFTER 01Z. EXPECT SOME MOUNTAIN OBSCURATION IN WESTERN WY THROUGH 00Z. EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND ROUTES VFR CONDITIONS WILL PREVAIL AT THE TERMINAL SITES THROUGH THE PERIOD. A GUSTY WIND WILL OCCUR TODAY AT MOST TERMINAL SITES WITH THE WIND DECREASING AFTER 02Z. ISOLATED RAIN SHOWERS OVER NORTHERN WY THROUGH 15Z. THEN BETTER COVERAGE OF SHOWERS IN NORTHERN WY BY 18Z THROUGH 00Z WITH SNOW IN THE BIGHORN MOUNTAINS. EXPECT MVFR/IFR CONDITIONS IN AND NEAR THE MOUNTAINS. AFTER 00Z WED SHOWERS WILL ON THE DECREASE IN NORTHERN WY WITH THE PRECIP ENDING BY 06Z WED. && .FIRE WEATHER... A SYSTEM WILL MOVE TO THE EAST OF THE AREA TODAY AND BRING SOME SHOWERS TO NORTHERN WYOMING...ESPECIALLY ACROSS THE NORTHEASTERN ZONES. BREEZY TO WINDY CONDITIONS WILL BE COMMON EAST OF THE DIVIDE WITH HIGH WINDS LIKELY ACROSS JOHNSON COUNTY. EXPECT GOOD SMOKE DISPERSAL WITH HIGH MIXING HEIGHTS. HIGH PRESSURE WILL THEN BRING MAINLY DRY CONDITIONS THROUGH THE REST OF THE WORKWEEK ALONG WITH LESS WIND. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 6 AM THIS MORNING TO MIDNIGHT MDT TONIGHT FOR WYZ010-011. && SHORT TERM...HATTINGS LONG TERM...AEM AVIATION...AR FIRE WEATHER...HATTINGS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 344 AM MDT TUE APR 5 2016 WYZ001>020-022>030-061200- 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- 344 AM MDT TUE APR 5 2016 ...HIGH WIND WARNING FOR JOHNSON COUNTY IN EFFECT FROM 6 AM THIS MORNING UNTIL MIDNIGHT TONIGHT... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT HIGH WINDS DEVELOPING ACROSS JOHNSON COUNTY WITH GUSTS NEAR 65 MPH POSSIBLE. WEST TO NORTHWEST WIND WITH GUSTS NEAR 50 MPH LIKELY ACROSS MUCH OF CENTRAL AND SOUTHERN WYOMING THIS AFTERNOON AND EVENING. MODERATE TO LOCALLY HEAVY SNOW COMBINED WITH STRONG NORTHWEST WIND WILL CAUSE AREAS OF BLOWING SNOW AND LIMITED VISIBILITY IN THE BIGHORN MOUNTAINS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SATURDAY AND SUNDAY...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS SPREADING INTO THE SOUTH AND WEST ON SATURDAY. A CANADIAN COLD FRONT WILL BRING SCATTERED TO NUMEROUS VALLEY RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ACROSS THE REGION ON SUNDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE URGED TO REPORT ANY WIND GUSTS OF 50 MPH OR GREATER AND ANY SNOWFALL AMOUNTS. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 218 AM MDT TUE APR 5 2016 WYZ019-020-022-052200- GREEN MOUNTAINS AND RATTLESNAKE RANGE- NATRONA COUNTY LOWER ELEVATIONS-CASPER MOUNTAIN- INCLUDING THE CITIES OF...JEFFREY CITY...CASPER 218 AM MDT TUE APR 5 2016 WEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ030-052200- EAST SWEETWATER COUNTY- INCLUDING THE CITY OF...WAMSUTTER 218 AM MDT TUE APR 5 2016 WEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ015>018-052200- WIND RIVER MOUNTAINS EAST-UPPER WIND RIVER BASIN-WIND RIVER BASIN- LANDER FOOTHILLS- INCLUDING THE CITIES OF...DUBOIS...RIVERTON...SHOSHONI...LANDER 218 AM MDT TUE APR 5 2016 NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ003>005-052200- CODY FOOTHILLS-NORTH BIG HORN BASIN-SOUTHWEST BIG HORN BASIN- INCLUDING THE CITIES OF...CODY...MEETEETSE...THERMOPOLIS 218 AM MDT TUE APR 5 2016 WEST TO NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ008-009-052200- BIGHORN MOUNTAINS WEST-BIGHORN MOUNTAINS SOUTHEAST- 218 AM MDT TUE APR 5 2016 NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON AND EVENING. WINDS OF 25 TO 35 MPH WITH GUSTS TO 45 TO 55 MPH WILL BE POSSIBLE. IN ADDITION...LOCALLY HEAVY SNOW SHOWERS WILL DEVELOP LATER THIS MORNING INTO THIS EVENING WITH A 1 TO 3 INCHES OF ACCUMULATION POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR SUDDEN REDUCTION IN VISIBILITY...SLICK ROADS IN SPOTS...AS WELL AS FOR THE STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES.
SPECIAL WEATHER STATEMENT...CORRECTED NATIONAL WEATHER SERVICE RIVERTON WY 218 AM MDT TUE APR 5 2016 WYZ019-020-022-052200- GREEN MOUNTAINS AND RATTLESNAKE RANGE- NATRONA COUNTY LOWER ELEVATIONS-CASPER MOUNTAIN- INCLUDING THE CITIES OF...JEFFREY CITY...CASPER 218 AM MDT TUE APR 5 2016 WEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ030-052200- EAST SWEETWATER COUNTY- INCLUDING THE CITY OF...WAMSUTTER 218 AM MDT TUE APR 5 2016 WEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ015>018-052200- WIND RIVER MOUNTAINS EAST-UPPER WIND RIVER BASIN-WIND RIVER BASIN- LANDER FOOTHILLS- INCLUDING THE CITIES OF...DUBOIS...RIVERTON...SHOSHONI...LANDER 218 AM MDT TUE APR 5 2016 NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ003>005-052200- CODY FOOTHILLS-NORTH BIG HORN BASIN-SOUTHWEST BIG HORN BASIN- INCLUDING THE CITIES OF...CODY...MEETEETSE...THERMOPOLIS 218 AM MDT TUE APR 5 2016 WEST TO NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON. WINDS OF 20 TO 30 MPH WITH GUSTS TO 40 TO 50 MPH WILL BE POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES. WYZ008-009-052200- BIGHORN MOUNTAINS WEST-BIGHORN MOUNTAINS SOUTHEAST- 218 AM MDT TUE APR 5 2016 NORTHWEST WINDS WILL INCREASE ACROSS THE AREA INTO THIS AFTERNOON AND EVENING. WINDS OF 25 TO 35 MPH WITH GUSTS TO 45 TO 55 MPH WILL BE POSSIBLE. IN ADDITION...LOCALLY HEAVY SNOW SHOWERS WILL DEVELOP LATER THIS MORNING INTO THIS EVENING WITH 1 TO 3 INCHES OF ACCUMULATION POSSIBLE. MOTORISTS SHOULD BE PREPARED FOR SUDDEN REDUCTION IN VISIBILITY...SLICK ROADS IN SPOTS...AS WELL AS FOR THE STRONG WIND WHICH COULD RESULT IN CONTROL ISSUES FOR LIGHT WEIGHT OR HIGH PROFILE VEHICLES.
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
Wind gusts as high as 72 mph where recorded in the vicinity of Clark.
The ASOS at the Johnson County Airport recorded a wind gust of 58 mph. A wind gust of 58 mph was also recorded at the Piney Creek mesonet site along Interstate 90 north of Buffalo.
The mesonet sensor at I-25 Divide registered sustained winds topping 40 mph for a few hours.
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, April 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: 618782, 618783, 632675.