A Pacific low pressure system moved across Montana and brought an associated cold front across Wyoming and produced a period of strong winds.
Every event with a place to put it; 6 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 CYS wrote it up.
A Pacific low pressure system moved across Montana and brought an associated cold front across Wyoming and produced a period of strong winds.
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 Oct 29, 1:39 AM MST, 46 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 239 AM MDT SAT OCT 29 2011 .SHORT TERM...TODAY THROUGH MONDAY NIGHT FORECAST CHALLENGES CONTINUE TO BE HIGH WIND POTENTIAL TODAY...FOLLOWED BY A NEXT WINTER WEATHER EVENT BEGINNING MONDAY EVENING INTO TUESDAY. CURRENTLY...LOW PRESSURE SYSTEM THAT WAS OFF THE COAST OF BRITISH COLUMBIA 24 HOURS AGO HAS MOVED INLAND AND IS CURRENTLY MOVING INTO SOUTHERN ALBERTA PROVINCE THIS MORNING ASSOCIATED COLD FRONT APPEARS TO LIE ACROSS WESTERN MONTANA...SOUTHWESTWARD INTO EASTERN OREGON. LATEST MEDICINE BOW PROFILER OBSERVATION IS SHOWING WINDS INCREASING THE PAST 2 HOURS TO 45KTS IN THE LOWEST GATE AT 07Z...A SLOW BUT STEADY INCREASE IN WIND SPEEDS. AREA OBSERVATIONS SHOWING SUSTAINED WINDS OUT BY ARLINGTON UP TO 35 MPH...GUSTING INTO THE MID 40S. FURTHER WEST IN THE GULF OF ALASKA...A PRETTY GOOD STORM SYSTEM LOOKS TO BE DEVELOPING...WHICH LOOKS TO IMPACT US THE BEGINNING OF NEXT WEEK. FOR TODAY...GFS CONTINUES TO SHOW 700MB WINDS IN EXCESS OF 50KTS OVER THE WESTERN PORTIONS OF THE CWA AFTER 12Z THIS MORNING...WHILE NAM SHOWS SLIGHTLY LESS AT 45KTS. LOCAL WRKHGT PRODUCT SHOWS STRONGEST 850 AND 700MB CRAIG TO CASPER HGT GRADIENTS FROM THE 12Z TO 18Z TIME PERIOD. WILL KEEP THE CURRENT HIGH WIND WARNING GOING AND WILL CONTINUE MONITORING WIND REPORTS AS WELL AS THE MEDICINE BOW PROFILER WINDS THIS MORNING. COLD FRONT LOOKS TO PASS THROUGH THE CWA AROUND THE 21Z TIME FRAME WITH WINDS SHIFTING NORTHWEST. 700MB TEMPERATURES FALL SLIGHTLY BEHIND THE FRONT...DROPPING FROM +2C THIS MORNING DOWN TO -4C THIS EVENING. TEMPERATURES SUNDAY LOOK TO BE ROUGHLY 3-5 DEGREES COLDER OVER TODAYS HIGHS WITH LOW TO MID 50S AREA WIDE. 700MB TEMPERATURES QUICKLY REBOUND THOUGH WITH 0 TO +2C 700MB TEMPERATURES RETURNING BY SUNDAY AFTERNOON. MONDAY LOOKS PRIMARILY DRY WITH INCREASING CLOUDINESS DURING THE AFTERNOON AS THE COLD FRONT APPROACHES NORTHWESTERN WYOMING. FAIRLY GOOD AGREEMENT ON TROUGH PLACEMENT MONDAY NIGHT INTO TUESDAY MORNING WITH QPF INTO CARBON AND ALBANY COUNTIES BY EARLY TUESDAY MORNING. ENERGY FROM THE APPROACHING SYSTEM TRACKS SOUTH INTO UTAH MONDAY EVENING AND TRACKS INTO NORTHWESTERN COLORADO TUESDAY MORNING...SETTING THE STAGE FOR OUR NEXT WINTER WEATHER EVENT. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT...MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK...BUT THEN DIVERGE CONSIDERABLY BY LATE IN THE WEEK AS A GRADUAL SHIFT IN THE LONG WAVE PATTERN IS EXPECTED. THE MAIN FORECAST CONCERN WILL BE THE POSSIBLE WINTER WEATHER EVENT TUESDAY THROUGH EARLY WEDNESDAY. MODELS ARE IN EVEN BETTER AGREEMENT WITH THIS SYSTEM COMPARED TO 24 HOURS AGO...SO CONTINUED TO INCREASE POP WELL INTO THE LIKELY CATEGORY ACROSS THE MAJORITY OF SOUTHEAST WYOMING AND WESTERN NEBRASKA ON TUESDAY. THIS SYSTEM IS LOOKING VERY SIMILAR TO THE TUESDAY/WEDNESDAY SNOW STORM LAST WEEK...WHICH PRODUCED 7 TO 14 INCHES OF SNOW NEAR THE COLORADO BORDER. CURRENT 00Z MODELS ARE A BIT FURTHER NORTH WITH THE UPPER LEVEL TROUGH AND ASSOCIATED DYNAMICS COMPARED TO THE PREVIOUS STORM...SO EXPECT PRECIPITATION TO BE MORE WIDESPREAD WITH ACCUMULATING SNOWFALL EXPECTED FURTHER NORTH TOWARDS DOUGLAS...ALLIANCE AND POSSIBLY CHADRON THIS TIME AROUND. ENSEMBLES SUPPORT THIS OUTCOME AS WELL...ALTHOUGH HALF OF THE ENSEMBLE PERTURBATIONS SHOW THE TROUGH MOVING A BIT QUICKER COMPARED TO THE PREVIOUS STORM. IN ADDITION...DYNAMIC FORCING APPEARS TO BE A LITTLE MORE FAVORABLE FOR WIDESPREAD MODERATE TO HEAVY SNOW ACCUMULATIONS ALONG WITH STRONGER WINDS ACROSS SOUTHEAST WYOMING. TOO EARLY TO PREDICT SNOWFALL AMOUNTS...BUT THERE IS A GOOD CHANCE FOR LOCATIONS ALONG AND EAST OF THE LARAMIE RANGE TO RECEIVE 6+ INCHES OF SNOW. EXPECT PRECIP TO START OFF AS RAIN BELOW 5000 FEET...LIMITING SNOW ACCUMULATIONS ACROSS WESTERN NEBRASKA AND THE LOWER VALLEYS OF SOUTHEAST WYOMING. AFTER A BRIEF WARM UP ON MONDAY...HIGH TEMPERATURES WILL RETURN TO THE 30S AND 40S TUESDAY AND WEDNESDAY BEHIND THE FRONT WITH CHILLY OVER NIGHT LOWS. HIGH TEMPERATURES WILL LIKELY STRUGGLE TO REACH 30 DEGREES ACROSS THE HIGH PLAINS AND HIGH VALLEYS OF WYOMING ON WEDNESDAY WITH 700MB TEMPS AS LOW AS -14C AND UPSLOPE LLVL FLOW. BY LATE WEDNESDAY AND INTO THURSDAY...AN UPPER LEVEL RIDGE AXIS WILL MOVE INTO THE ROCKIES RESULTING IN COLD OVERNIGHT LOWS DUE TO CLEAR SKIES AND GOOD RADIATIONAL COOLING. FURTHER OUT...EXTENDED MODELS ARE STILL HINTING AT A SHIFT IN THE LONG WAVE PATTERN...WITH THE ECMWF SHOWING A SERIES OF DEEP UPPER LEVEL TROUGHS PUSHING EASTWARD ACROSS THE WESTERN UNITED STATES...EVEN AS FAR SOUTH AS CNTRL AND SOUTHERN CALIFORNIA. GFS AND DGEX NOT AS AGGRESSIVE...BUT BOTH MODELS STILL SHOW A STRONG COLD FRONT PUSHING ACROSS WYOMING BY FRIDAY WITH PROGRESSIVE WEST TO NORTHWEST FLOW ALOFT. KEPT POP AROUND 10 PERCENT FOR NOW DUE LARGE DIFFERENCES BETWEEN THE GFS AND ECMWF. HOWEVER...INCREASED POP UP TO 40 PERCENT IN THE MOUNTAINS AND ALSO STARTED TO LOWER TEMPERATURES WELL BELOW NORMAL WITH ALL MODELS SHOWING MUCH COLDER AIR PUSHING INTO THE AREA AND REMAINING OVER THE AREA INTO NEXT WEEKEND. MODEL CONSENSUS SHOWS HIGH TEMPERATURES STRUGGLING TO REACH THE MIDDLE 30S BY FRIDAY AND SATURDAY NEXT WEEK WITH THE POTENTIAL FOR VERY COLD OVERNIGHT LOWS. && .AVIATION...06Z TAF ISSUANCE. VFR CONDITIONS WILL PREVAIL WITH MID TO HIGH CLOUDINESS OVERHEAD IN ADVANCE OF THE NEXT PACIFIC COLD FRONT. THE LEE TROUGH OVER CENTRAL WYOMING WILL DEEPEN...WITH WESTERLY SURFACE WINDS INCREASING TONIGHT THROUGH SATURDAY MORNING. WIND GUSTS OF 40 KT OR HIGHER ARE EXPECTED ALONG AND WEST OF THE LARAMIE RANGE...WITH GUSTS TO 35 KT EAST OF THE RANGE ON SATURDAY. && .FIRE WEATHER... GUSTY WEST TO NORTHWEST WINDS TODAY AS A COLD FRONT TRACKS ACROSS MONTANA. EXPECTING WINDY CONDITIONS FOR OUR WIND PRONE AREAS AND HIGHER TERRAIN AREAS ALONG THE LARAMIE RANGE TODAY. AFTERNOON HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL LEVELS TODAY WITH LOW 20S EXPECTED. NEXT CHANCE FOR PRECIPITATION LOOKS TO BE MONDAY NIGHT INTO TUESDAY AS A MORE POTENT PACIFIC STORM SYSTEM MOVES INTO SOUTHEASTERN WYOMING...BRINGING MEASURABLE SNOWFALL TO MOST LOCATIONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...HIGH WIND WARNING UNTIL 6 PM SATURDAY FOR WYZ106-WYZ110-WYZ116. NE...NONE. && SHORT TERM/FIRE WEATHER...CLAYCOMB LONG TERM/AVIATION...TJT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 850 PM MDT FRI OCT 28 2011 WYZ101>119-291200- 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- 850 PM MDT FRI OCT 28 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL WYOMING... SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TONIGHT WEST WINDS WILL INCREASE LATER TONIGHT ALONG AND WEST OF THE LARAMIE RANGE. IN THE WIND PRONE AREAS OF BORDEAUX...ARLINGTON AND VEDAUWOO...WINDS WILL GUST AS HIGH AS 60 MPH. A HIGH WIND WARNING IS IN EFFECT FOR THESE AREAS BEGINNING AT 3 AM. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY STRONG AND GUSTY WEST WINDS WILL CONTINUE THROUGH SATURDAY AFTERNOON AHEAD OF A STRONG COLD FRONT. WINDS MAY GUST AS HIGH AS 55 MPH OVER MUCH OF SOUTHEAST WYOMING ON SATURDAY. FOR THE WIND PRONE AREAS OF BORDEAUX...ARLINGTON AND VEDAUWOO...WINDS GUSTING IN EXCESS OF 60 MPH ARE EXPECTED AND THE HIGH WIND WARNING WILL REMAIN IN EFFECT THROUGH 6 PM. COLDER TEMPERATURES...RAIN AND SNOW WILL RETURN TO SOUTHEAST WYOMING BEGINNING TUESDAY AFTERNOON AND CONTINUING THROUGH WEDNESDAY. ACCUMULATING SNOW IS LIKELY TUESDAY NIGHT AND WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE NEZ002-003-019>021-054-055-095-096-291200- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX- 850 PM MDT FRI OCT 28 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA PANHANDLE. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY WEST TO NORTHWEST WINDS WILL GUST AS HIGH AS 40 MPH ON SATURDAY... ESPECIALLY FOR AREAS BORDERING WYOMING. COLDER TEMPERATURES...RAIN AND SNOW WILL RETURN TO THE WESTERN NEBRASKA PANHANDLE TUESDAY NIGHT AND WEDNESDAY. ACCUMULATING SNOW IS LIKELY DURING THAT TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE JAMSKI
The national radar mosaic for the moment the first event began.
6 high wind. Local standard time, as filed.
WYDOT sensors across the Northern Snowy Range foothills measured sustained winds in excess of 40 mph for several hours.
A WYDOT sensor near Vedauwoo measured sustained winds in excess of 40 mph for several hours.
A WYDOT sensor near the Bordeaux exit on Interstate 25 measured sustained winds in excess of 40 mph for several hours with a peak gust of 58 mph.
Te Dodge Creek RAWS measured a peak gust of 61 mph.
A WYDOT sensor at Remount Road measured a peak gust of 63 mph.
UP railroad sensor at Emkay measured wind gusts in excess of 60 mph for several hours with a peak gust of 73 mph at 245 PM MDT.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2011Every state in 2011This day in weather historyWarnings in Wyoming, October 2011
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: 346341, 346342, 346339, 346344, 346343, 346601.