A short-lived tornado touched down over open country.
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 CYS wrote it up.
A short-lived tornado touched down over open country.
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 May 17, 12:39 PM MST, 1 hour 50 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 139 PM MDT THU MAY 17 2007 .SHORT TERM...TONIGHT THROUGH SATURDAY. TONIGHT...SCATTERED THUNDERSTORMS HAVE BEEN DEVELOPING ALONG NORTH-SOUTH SURFACE TROUGH CONVERGENCE AXIS ACROSS ALBANY COUNTY. PER CONVECTIVE PARAMETERS...BELIEVE AREAL COVERAGE OF THUNDERSTORMS WILL CONTINUE TO INCREASE AS THE STORMS MOVE INTO INCREASED LOW LEVEL MOISTURE AVAILABILITY AND WITH SHORT WAVE TROUGH MOVING THROUGH AT PEAK HEATING. ALTHOUGH THE MAJORITY OF STORMS WILL REMAIN BELOW SEVERE LEVELS PER CAPE AND SHEAR PARAMETERS...ONE OR TWO ISOLATED SEVERE STORMS NOT OUT OF THE QUESTION PER MINIMAL CAPES. THUNDERSTORMS WILL CONTINUE TO DECREASE AS THE EVENING WANES WITH LOSS OF SOLAR INSOLATION. WILL LIKELY SEE WIDESPREAD LOW CLOUDS AND AREAS OF FOG LATE AS OCCURRED THIS MORNING...ACROSS WESTERN NEBRASKA PER NAM LOW LEVEL AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS. FRIDAY/FRIDAY NIGHT...ANOTHER SURFACE CONVERGENCE AXIS DEVELOPS ACROSS FAR EASTERN WYOMING SERVING AS A FOCUS FOR THUNDERSTORM INITIATION. WILL SEE LESS AFTERNOON/EVENING THUNDERSTORM COVERAGE COMPARED TO TODAY DUE TO DRYING AT LOW/MID LEVELS WITH WESTERLY FLOW AND WARM TEMPERATURES ALOFT. GREATER POTENTIAL FOR STRONG WIND GUSTS WITH INVERTED V TYPE SOUNDINGS AND LARGER SURFACE TEMPERATURE/DEWPOINT SPREADS. SATURDAY...BACKDOOR COLD FRONT SLIDES INTO OUR NORTHEAST ZONES SERVING AS A FOCUS FOR AFTERNOON THUNDERSTORM INITIATION. LESS THUNDERSTORM COVERAGE IN OUR SOUTHEAST ZONES WHERE AIRMASS WILL REMAIN MOSTLY CAPPED BY WARM MID LEVEL TEMPERATURES. TEMPERATURES STILL WARM...15-20 DEGREES ABOVE NORMAL...PER 1000-500 MB THICKNESS PROGS. .LONG TERM...THE RIDGE AXIS ALOFT WILL MOVE EAST OF THE CWA SATURDAY NIGHT IN ADVANCE OF THE APPROACHING SHORTWAVE TROUGH. THE SHALLOW COLD FRONT LOOKS TO MAKE IT TO THE 5000 FOOT MSL ELEVATION SATURDAY EVENING BEFORE BEING ERODED EASTWARD LATER THAT NIGHT. WILL KEEP SOME THUNDERSTORMS NEAR AND WEST OF THE FRONT SATURDAY EVENING. THE SHORTWAVE TROUGH MOVES EAST AND ACROSS THE CWA THE FIRST HALF OF NEXT WEEK AND WILL BE THE MAJOR FACTOR IN THE WEATHER FOR THE AREA DURING THAT TIME. MODELS DIFFER IN THEIR TIMING OF THE FEATURE WHICH WAS AT ABOUT 47N AND 150W AT MIDDAY PER SATELLITE IMAGERY. THE GFS CONTINUES TO HAVE THE FASTEST MOVEMENT OF THE SHORTWAVE TROUGH AND ITS 12Z RUN WAS 6 TO 12 HOURS FASTER THAN ALL OTHER MODELS. THE GFS IS TRENDING SLOWER IN ITS PAST FEW RUNS...BUT THE SLOWER MOVEMENT INDICATED FROM MOST OTHER MEDIUM RANGE MODELS IS PREFERRED BY HPC. THE UPPER LEVEL TROUGH AXIS MOVES EAST OF THE CWA BY TUESDAY EVENING PER THE SLOWER MODEL CONSENSUS. THE ENERGY WILL BE SOMEWHAT SPLIT WITH ANOTHER SIGNIFICANT SHORTWAVE TROUGH MOVING ACROSS CANADA AT ABOUT THE SAME LONGITUDE. THE ASSOCIATED COLD FRONT WILL MOVE ACROSS THE CWA MONDAY AFTERNOON AND EVENING WITH A SURFACE LOW ALONG THE FRONT AND ENDING UP IN EASTERN COLORADO BY MONDAY EVENING. COLD AIR ADVECTION BEHIND THE FRONT AND SHORTWAVE TROUGH WILL LOWER THE TEMPERATURES 10 DEGREES FROM MONDAY TO TUESDAY. WILL BUMP UP POPS MONDAY AFTERNOON THROUGH TUESDAY DUE TO THE ADDED DYNAMICS...SURFACE FORCING...MOISTURE AND INSTABILITY. PRIOR TO THE ARRIVAL OF THOSE FEATURES...MOST MODELS STILL INDICATE A WEAKER SHORTWAVE TROUGH MOVING OVER THE CWA SUNDAY AFTERNOON AND EVENING AND WILL ALSO BUMP UP THE MENTION OF THUNDERSTORMS FOR THOSE TIMES. HEIGHTS ALOFT RISE FOR WEDNESDAY AND SOME MODELS INDICATE ANOTHER SHORTWAVE TROUGH WILL AFFECT THE CWA ON NEXT THURSDAY. WILL KEEP THE CWA DRY FOR WEDNESDAY AND LOW POPS FOR THURSDAY. && .AVIATION...MVFR IN SCATTERED THUNDERSTORMS THROUGH 9 PM...OTHERWISE VFR. EXPECT AREAS OF IFR LATE TONIGHT THROUGH MID MORNING FRIDAY IN FOG/LOW CLOUDS ACROSS THE WESTERN NEBRASKA PANHANDLE. MVFR AGAIN FRIDAY AFTERNOON IN SCATTERED THUNDERSTORMS. OTHERWISE VFR. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && SHORT TERM/AVIATION...RUBIN LONG TERM....WEILAND
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 955 AM MDT THU MAY 17 2007 NEZ001>003-019>021-054-055-WYZ059>070-181130- SIOUX-DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL- CHEYENNE-CONVERSE-NIOBRARA-SOUTHWEST CARBON-NORTH CARBON- SNOWY RANGE-NORTH LARAMIE RANGE-LARAMIE VALLEY-LARAMIE RANGE- PLATTE-GOSHEN-CHEYENNE FOOTHILLS-PINE BLUFFS- 955 AM MDT THU MAY 17 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA PANHANDLE AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR THIS AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25. WIND GUSTS UP TO 50 MPH AND HAIL UP TO PEA SIZE ARE LIKELY WITH THE MAJORITY OF THE STRONGEST STORMS. ONE OR TWO ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE...WITH WIND GUSTS IN EXCESS OF 60 MPH AND PENNY SIZE HAIL. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THERE IS A CHANCE OF LATE DAY THUNDERSTORMS FRIDAY THROUGH TUESDAY ACROSS THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. YOUR NATIONAL WEATHER SERVICE APPRECIATES ANY SPOTTER REPORTS ABOUT THUNDERSTORMS. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE
The Cheyenne radar (KCYS), 125 km away, was scanning. The volume nearest the first event began at 21:29 UTC.
1 tornado. Local standard time, as filed.
Brief tornado spotted just east of Interstate 25 near mile marker 94.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2007Every state in 2007This day in weather historyThe tornado archive for Wyoming, 2007Warnings in Wyoming, May 2007
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: 22293.