A thunderstorm produced wind gusts to near 60 mph just north of Douglas in Converse County.
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The episode as NWS CYS wrote it up.
A thunderstorm produced wind gusts to near 60 mph just north of Douglas in Converse County.
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 Jul 20, 5:05 PM MST, 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 605 PM MDT FRI JUL 20 2012 .AVIATION...00Z TAFS. VFR PREVAILING. THROUGH 03Z...ISOLATED SHOWERS AND THUNDERSTORMS NORTH OF A LINE FROM CHEYENNE TO ALLIANCE ...PRODUCING TURBULENCE. AFTER 18Z...ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING AGAIN PRODUCING TURBULENCE. RUBIN && .PREV DISCUSSION... /ISSUED 155 PM MDT FRI JUL 20 2012/ SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT... VERY ISOLATED CONVECTION CURRENT INDICATED ON 88D OVER THE CWA... LESS THAN AT THIS TIME YESTERDAY. WATER VAPOR LOOPS SHOW A DRIER PUSH OF AIR SPREADING ACROSS THE CWA IN THE WAKE OF AN UPPER IMPULSE NOW MOVING NORTHEAST OVER MONTANA. WILL MAINTAIN LOW POPS INTO EARLY THIS EVENING OVER WESTERN AND NORTHERN PORTIONS OF THE CWA WHERE THE BETTER MOISTURE WILL RESIDE FOR A WHILE STILL. LITTLE CHANGE SEEN IN THE OVERALL WEATHER PATTERN SATURDAY THROUGH SUNDAY AS UPPER HIGH REMAINS ANCHORED OVER THE CENTRAL PLAINS WITH THE CWA ON THE NW SIDE. MODEST MONSOONAL MOISTURE WILL CONTINUE TO RIDE AROUND THIS UPPER HIGH AND ACROSS THE CWA THUS WIDELY SCTD MAINLY LATE DAY CONVECTION SHOULD CONTINUE...LEAST LIKELY OVER FAR SOUTHEASTERN SECTIONS CLOSER TO THE UPPER HIGH AND WARMER MID LEVEL TEMPS. ACTIVITY OVER NORTHERN PARTS OF THE CWA MAY BE AIDED BY A WEAK SFC BOUNDARY THAT SHOULD SAG INTO EAST CENTRAL WY AND THE NORTHERN PANHANDLE. VERY LITTLE EFFECT FROM THIS BOUNDARY OTHERWISE AS TEMPERATURES WILL REMAIN VERY WARM TO HOT. LONG TERM...MONDAY THROUGH FRIDAY... STAGNANT WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEK. MODELS SHOW THE PERSISTENT UPPER LEVEL HIGH OVER THE CENTRAL ROCKIES AND HIGH PLAINS TEMPORARILY BUILDING WESTWARD OVER THE FOUR CORNERS REGION ON WEDNESDAY. THE HIGH WILL THEN PUSH EASTWARD ONCE AGAIN OVER THE SAME AREA AS THIS WEEKEND AND BUILD NORTHWARD. EXPECT VERY WARM OR HOT TEMPERATURES TO CONTINUE WITH HIGHS IN THE 90S TO 105 DEGREES OVER THE HIGH PLAINS...WARMEST OVER THE LOWER ELEVATIONS OF WESTERN NEBRASKA...AND HIGHS IN THE 80S TO NEAR 90 WEST OF THE LARAMIE RANGE. WITH SUBTROPICAL MOISTURE REMAINING IN PLACE MONDAY AND TUESDAY...EXPECT A CONTINUATION OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON/EVENING ACROSS MOST OF THE FORECAST AREA. KEPT POP BETWEEN 20 TO 50 PERCENT...HIGHEST IN THE MOUNTAINS AND ADJACENT VALLEYS. AS THE MID TO UPPER LEVEL FLOW VEERS INTO THE WEST ON WEDNESDAY...SOME DRIER AIR WILL PUSH INTO SOUTHEAST WYOMING AS THE A WEAK COOL FRONT MOVES SOUTHWARD OVER THE AREA. THIS WILL LIKELY LIMIT CONVECTION DURING THE DAY AS SURFACE WINDS SHIFT INTO THE NORTHEAST. HOWEVER...SHOWERS AND TSTORMS WILL LIKELY RETURN TO THE AREA ON THURSDAY AND FRIDAY AS THE UPPER LEVEL HIGH SHIFTS EAST OVER THE CENTRAL ROCKIES. A SURFACE COOL FRONT WILL STALL NEAR THE LARAMIE RANGE...RESULTING IN A HIGHER CHANCE OF SHOWERS AND THUNDERSTORMS...POSSIBLY INTO THE LATE EVENING HOURS. TEMPERATURES ARE EXPECTED TO LOWER SLIGHTLY...BUT STILL REMAIN NEAR OR 5 TO 10 DEGREES ABOVE NORMAL. AVIATION...18Z TAF ISSUANCE... VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT WITH RELATIVELY LIGHT WINDS...ALTHOUGH SOUTHWEST WINDS MAY BECOME GUSTY THIS AFTERNOON AROUND KRWL AND KSNY. ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS EARLY THIS AFTERNOON...WITH A FEW STORMS MOVING NORTHEAST ACROSS THE PLAINS. A FEW STORMS WILL PERSIST THROUGH LATE THIS EVENING ACROSS THE HIGH PLAINS AS A COLD FRONT MOVES SOUTH ACROSS THE PLAINS AFTER 00Z. GUSTY WINDS UP TO 40KTS AND LOCALIZED TURBULENCE ARE EXPECTED FROM THESE STORMS WHICH SHOULD DISSIPATE BY 05Z. FIRE WEATHER... VERY WARM CONDITIONS WILL CONTINUE OVER THE DISTRICTS INTO EARLY NEXT WEEK WITH MINIMUM RELATIVE HUMIDITIES LOWERING TO AROUND 15% MOST DAYS. WINDS WILL REMAIN GENERALLY LIGHT HOWEVER WHICH WILL REDUCE FIRE CONCERNS. SOME WIDELY SCATTERED MAINLY LATE DAY SHOWERS AND TSTMS WILL OCCUR MAINLY OVER WESTERN AND NORTHERN DISTRICTS BUT ACTIVITY SHOULD FOR THE MOST PART HAVE ENOUGH RAIN TO LOWER DRY LIGHTNING THREAT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...HEAT ADVISORY UNTIL 9 PM FRIDAY FOR NEZ002. && SHORT TERM/FIRE WEATHER...RE LONG TERM/AVIATION...TJT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 1035 AM MDT FRI JUL 20 2012 WYZ101>119-211115- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- NORTH LARAMIE RANGE-FERRIS/SEMINOE/SHIRLEY MOUNTAINS- SHIRLEY BASIN-CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- EAST PLATTE COUNTY-GOSHEN COUNTY-CENTRAL CARBON COUNTY- NORTH SNOWY RANGE FOOTHILLS-SOUTHWEST CARBON COUNTY- SIERRA MADRE RANGE-UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE- LARAMIE VALLEY-SOUTH LARAMIE RANGE-SOUTH LARAMIE RANGE FOOTHILLS- CENTRAL LARAMIE COUNTY-EAST LARAMIE COUNTY- 1035 AM MDT FRI JUL 20 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL WYOMING... SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON OVER THE SOUTHEAST WYOMING MOUNTAINS...WITH AN ISOLATED COVERAGE EXPECTED ACROSS THE EASTERN PLAINS. OCCASIONAL LIGHTNING AND GUSTY WINDS WILL ACCOMPANY THESE THUNDERSTORMS. THE STORMS WILL DISSIPATE DURING THE EVENING HOURS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORM CHANCES WILL CONTINUE THROUGH EARLY NEXT WEEK AS MONSOONAL MOISTURE CONTINUES TO MOVE ACROSS THE AREA. A FEW OF THESE THUNDERSTORMS MAY CONTAIN HEAVY RAIN ESPECIALLY EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE NEZ002-003-019>021-054-055-095-096-211115- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX- 1035 AM MDT FRI JUL 20 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA PANHANDLE. .DAY ONE...TODAY AND TONIGHT VERY HOT TEMPERATURES WILL OCCUR ACROSS THE ENTIRE PANHANDLE TODAY...WITH HIGHS EXPECTED TO BE BETWEEN 100 AND 110 DEGREES. ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS THE NORTHERN HALF OF THE PANHANDLE LATE THIS AFTERNOON INTO EARLY THIS EVENING. GUSTY WINDS AND OCCASIONAL LIGHTNING WILL OCCUR WITH THESE STORMS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORM CHANCES WILL CONTINUE THROUGH EARLY NEXT WEEK AS MONSOONAL MOISTURE WILL CONTINUE TO MOVE INTO THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 349 PM MDT FRI JUL 20 2012 WYZ105-106-110-115-202245- CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY WY-LARAMIE VALLEY WY-NORTH SNOWY RANGE FOOTHILLS WY-SHIRLEY BASIN WY- 349 PM MDT FRI JUL 20 2012 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL ALBANY COUNTY UNTIL 445 PM MDT... AT 345 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 11 MILES SOUTH OF ROCK RIVER...OR 26 MILES NORTHWEST OF LARAMIE...MOVING NORTH AT 15 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... ROCK RIVER AROUND 420 PM MDT. CROSSING HIGHWAY 30 AROUND 400 PM MDT. IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. && LAT...LON 4188 10605 4173 10551 4151 10586 4154 10607 TIME...MOT...LOC 2148Z 202DEG 12KT 4159 10591 RUBIN
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 408 PM MDT FRI JUL 20 2012 NEZ002-003-095-096-WYZ101>103-105>108-110-112>116-210300- DAWES-BOX BUTTE-NORTH SIOUX-SOUTH SIOUX- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- NORTH LARAMIE RANGE-SHIRLEY BASIN- CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- EAST PLATTE COUNTY-GOSHEN COUNTY-NORTH SNOWY RANGE FOOTHILLS- SIERRA MADRE RANGE-UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE- LARAMIE VALLEY-SOUTH LARAMIE RANGE- INCLUDING THE CITIES OF...CHADRON...ALLIANCE...HARRISON...AGATE... DOUGLAS...GLENROCK...LUSK...MEDICINE BOW...BORDEAUX...GLENDO... WHEATLAND...CHUGWATER...GUERNSEY...TORRINGTON...ARLINGTON... ELK MOUNTAIN...SARATOGA...ENCAMPMENT...RIVERSIDE...CENTENNIAL... ALBANY...WOODS LANDING...LARAMIE...VEDAUWOO...BUFORD... PUMPKIN VINE 408 PM MDT FRI JUL 20 2012 ...GUSTY WINDS FROM THUNDERSTORMS THROUGH EARLY EVENING... ISOLATED HIGH BASED SHOWERS AND THUNDERSTORMS WILL MOVE NORTHEAST AT 25 MPH THROUGH 9 PM. SOME OF THE SHOWERS AND THUNDERSTORMS WILL PRODUCE WIND GUSTS UP TO 55 MPH. RAINFALL AMOUNTS FROM THE STORMS WILL BE LESS THAN ONE TENTH OF AN INCH IN MOST CASES...WITH ISOLATED RAINFALL AMOUNTS UP TO ONE HALF OF AN INCH. RUBIN
The Cheyenne radar (KCYS), 189 km away, was scanning. The volume nearest the first event began at 00:07 UTC.
1 thunderstorm wind. Local standard time, as filed.
The ASOS wind sensor at the Converse County Airport measured a peak gust of 59 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2012Every state in 2012This day in weather historyWarnings in Wyoming, July 2012
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: 387871.