An upper low and cold front along with weak instability produced a brief period of moderate snowfall across the Snowy and South Laramie Ranges. Gusty northwest winds to 35 mph created blowing and drifting snow.
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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.
An upper low and cold front along with weak instability produced a brief period of moderate snowfall across the Snowy and South Laramie Ranges. Gusty northwest winds to 35 mph created blowing and drifting snow.
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 Feb 24, 10:55 PM MST, 4 hours 5 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 1055 PM MST TUE FEB 24 2015 .UPDATE... ISSUED AT 910 PM MST TUE FEB 24 2015 THE FIRST VESTIGES OF THE NEXT NORTHWEST FLOW WEATHER DISTURBANCE SHOWING UP ON RADAR AT THIS TIME. RADAR MOSAIC SHOWING SOME ECHOS ALONG THE NORTHERN FRINGES OF THE FORECAST AREA. CLOUD CEILINGS ARE CURRENTLY 8000 TO 10000 FEET AGL...SO STILL LOOKING AT A WHILE FROM SATURATION TO OCCUR WITH SNOW HITTING THE GROUND. ANY SNOW TONIGHT WILL BE ON THE LIGHT SIDE. LATEST NAM AND GFS HAVE BACKED OFF A BIT ON QPF AMOUNTS TONIGHT WHICH IS NOT TOO SURPRISING GIVEN THAT LOW TO MID LEVEL WINDS WILL REMAIN IN A WESTERN DOWNSLOPE DIRECTION ACROSS THE PLAINS. WILL ADJUST POPS AND SNOW ACCUMULATIONS A BIT FOR TONIGHT...BUT NO MAJOR CHANGES. OUTSIDE OF THE MOUNTAINS THE MAIN CHANCES FOR ACCUMULATING SNOW WILL NOT OCCUR UNTIL TOMORROW INTO TOMORROW NIGHT. AT THIS TIME SNOW ACCUMULATIONS ARE EXPECTED TO BE MINIMAL FOR MOST OF THE AREA...OF COURSE WILL HAVE TO KEEP AN EYE ON BANDED SNOWFALL POTENTIAL. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 358 PM MST TUE FEB 24 2015 TONIGHT...FAST MOVING SHORTWAVE TROUGH ALOFT SWEEPS SOUTHEASTWARD ACROSS THE NORTHERN AND CENTRAL ROCKIES...SENDING THE INITIAL SURGE OF COLDER AIR SOUTHWARD INTO OUR COUNTIES LATE TONIGHT...AND WITH THE LOW AND MID LEVELS SATURATING UP...ALONG WITH UPWARD VERTICAL MOTION FROM THE BAROCLINIC BAND AND OROGRAPHIC PROCESSES...WE EXPECT WIDESPREAD SNOWS TO CRANK UP OVER OUR SNOWY AND SIERRA MADRE RANGES AS WELL AS THE NORTHERN LARAMIE RANGE. WE ALSO EXPECT SCATTERED LIGHT SNOWS IN THE FEW HOURS BEHIND COLD FRONTAL PASSAGE. WEDNESDAY...NEXT SURGE OF ARCTIC AIR SWEEPS SOUTH ACROSS OUR COUNTIES NORTH TO SOUTH DURING THE DAY...WITH MODERATE TO STRONG COLD AIR ADVECTION IN ITS WAKE...THUS HAVE TOUCHED UP THE GRIDDED FORECASTS TO HAVE MAXIMUM TEMPERATURES AROUND MID MORNING WITH STEADY OR SLOWLY FALLING AFTERNOON TEMPERATURES. DECENT UPWARD VERTICAL MOTION SETS UP OVER A SATURATED AIRMASS ALONG AND WEST OF INTERSTATE 25 IN THE AFTERNOON...WHICH CORRESPONDS WELL TO THE 700- 500 MB AND 500-300 MB LAYERS WITH RESPECT TO QUASIGEOSTROPHIC FORCING...THUS WE HAVE BUMPED UP POPS NEAR 100 PERCENT ALONG AND WEST OF I-25 WITH 40 TO 80 PERCENT AFTERNOON POPS POST ARCTIC COLD FRONTAL. WEDNESDAY NIGHT...UPWARD MOTION WANES ALONG WITH LESS MOISTURE IN THE LOW AND MID LEVELS...THUS EXPECT A CORRESPONDING DECREASE IN AREAL SNOW COVERAGE AND INTENSITIES. THURSDAY...DECENT LOW AND MID LEVEL UPSLOPE DEVELOPS FROM THE SOUTHERN LARAMIE RANGE AND CHEYENNE SOUTHWARD ALONG THE FRONT RANGE OF COLORADO AS SEEN BY UPWARD VERTICAL MOTION FIELDS...AND THUS WE EXPECT AN INCREASE IN AREAL SNOW COVERAGE THURSDAY AFTERNOON WITH POPS FROM 30 TO 65 PERCENT FROM SOUTHERN ALBANY COUNTY ACROSS LARAMIE COUNTY INCLUDING CHEYENNE. MINIMAL ACCUMULATION LIKELY WITH LIMITED DYNAMICS THOUGH WITH POWDERY SNOW EXPECTED...SOME LOCALES MAY SEE 1 TO 3 INCHES...ESPECIALLY OVER THE SOUTHERN LARAMIE RANGE. THURSDAY NIGHT...LOW LEVEL EAST AND SOUTHEAST UPSLOPE DEVELOPS NICELY OVER THE LARAMIE VALLEY...SOUTHERN LARAMIE RANGE WEST OF CHEYENNE AND OVER LARAMIE COUNTY WYOMING INCLUDING CHEYENNE...THUS WE EXPECT WIDESPREAD FREEZING FOG TO DEVELOP...LIKELY DENSE AT TIMES DUE TO THIS COMMON WINTER AND SPRING PATTERN. WILL LIKELY ALSO SEE SOME LIGHT FLURRIES WITH MINIMAL ACCUMULATION...AND WILL NEED TO WATCH FOR THE POSSIBILITY OF FREEZING PRECIPITATION FROM LARAMIE TO CHEYENNE...IF THE COLD AIR DEPTH NEAR THE SURFACE IS SUFFICIENTLY OVERRUN BY THE SOUTHWEST AND WARMER 700 MB FLOW...THOUGH THIS POSSIBILITY SEEMS RELATIVELY REMOTE. BY DAWN ON FRIDAY...WE ARE ANTICIPATING TOTAL SNOWFALL AMOUNTS OF 1 TO 4 INCHES AT LOWER ELEVATIONS...MAINLY WEST OF INTERSTATE 25...WITH SNOWFALL AMOUNTS OF 5 TO 10 INCHES OVER THE MOUNTAINS...THUS LATER FORECAST SHIFT TEAMS MAY NEED TO ISSUE WINTER WEATHER ADVISORIES IN SOME LOCATIONS...ESPECIALLY OVER THE SNOWY AND SIERRA MADRE RANGES...AND OVER THE VALLEY LOCATIONS IN AND AROUND SARATOGA WHICH WILL HAVE FAVORABLE MOIST UPSLOPE TO THE NORTHERN SLOPES OF THE SNOWY AND SIERRA MADRE RANGES...THUS SNOWFALL EXPECTED TO BE LOCALLY HIGHER IN THESE LOCALES. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 358 PM MST TUE FEB 24 2015 PROGRESSIVE NORTHWEST FLOW LATE THIS WEEK WILL SPLIT OVER THE WEEKEND AS SHORTWAVE ENERGY BECOMES CUT OFF FROM THE NRN STREAM OVR THE GREAT BASIN. THIS FTR EVENTUALLY PHASES BACK INTO THE NRN STREAM EARLY NEXT WEEK. BEFORE THEN...LIKELY A FOGGY START TO THE DAY ON FRIDAY IN THE IMMEDIATE LEE OF THE LARAMIE RANGE AS LLVL FLOW TURNS SOUTHEASTERLY UPSLOPE. THERE MAY BE SOME FLURRIES AS WELL DURING THE MORNING HOURS AS WELL...THOUGH CONFIDENCE IS HIGHEST IN THE FOG/LOW STRATUS SCENARIO. FRIDAY WILL BE DRY FOR AREAS OUTSIDE OF THE MOUNTAINS...BUT STILL COLD WITH HIGHS ONLY REACHING THE TEENS/LOW 20S. FLOW BACKS TO THE SOUTHWEST ON SATURDAY AS THE AFOREMENTIONED SHORTWAVE ENERGY CUTS OFF OVR THE GREAT BASIN. SOUTHWEST FLOW AROUND THE POSITIVELY TILTED TROF WILL PRODUCE FAVORABLE ISENTROPIC LIFT SET-UP...THE BULK OF WHICH IS PROGD TO STAY SOUTH OVR COLORADO. MAY SEE ANOTHER COUPLE OF INCHES HOWEVER...MOST OF WHICH WILL BE CONFINED TO AREAS ALONG THE COLORADO/WYOMING STATELINE. THIS SYSTEM PHASES WITH THE NRN STREAM ON SUNDAY...KICKING IT OUT INTO THE PLAINS. ANOTHER COLD DAY AHEAD FOR SUNDAY WITH JUST SOME LINGERING SNOW SHOWERS POSSIBLE AS THE SHORTWAVE ENERGY EJECTS INTO THE PLAINS. MONDAY LOOKS DRY WITH TEMPERATURES PERHAPS RETURNING BACK TO FREEZING. ALTHOUGH MEDIUM RANGE GUIDANCE STRUGGLES IN TIMING AND STRENGTH DURING ACTIVE PATTERNS...THERE MAY BE ANOTHER LIGHT SNOW EVENT AGAIN FOR NEXT TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1053 PM MST TUE FEB 24 2015 LIGHT SNOW WILL SPREAD INTO SOUTHEAST WYOMING AND PORTIONS OF THE NEBRASKA PANHANDLE LATE TONIGHT. LIGHT SNOW WILL REMAIN POSSIBLE THROUGH WEDNESDAY AND INTO WEDNESDAY NIGHT. THE MAIN FOCUS FOR SNOW WILL BE ALONG AND WEST OF THE LARAMIE RANGE WHERE SNOW MAY BECOME MODERATE AT TIMES. SNOWY AND SIERRA MADRE RANGE MOUNTAINS WILL BE OBSCURED. && .FIRE WEATHER... ISSUED AT 358 PM MST TUE FEB 24 2015 NO ISSUES EXPECTED BASED ON PROGGED HUMIDITIES AND WINDS AND EXPECTED SNOWFALL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && UPDATE...SML SHORT TERM...RUBIN LONG TERM...CAH AVIATION...SML FIRE WEATHER...RUBIN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 411 AM MST TUE FEB 24 2015 WYZ101>119-251115- 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- 411 AM MST TUE FEB 24 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WYOMING...SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY A STRONG COLD FRONT WILL MOVE SOUTHWARD ACROSS THE REGION ON WEDNESDAY...BRINGING COLD TEMPERATURES AND A GOOD CHANCE FOR WIDESPREAD LIGHT SNOWFALL. ACCUMULATIONS ACROSS LOWER ELEVATIONS SHOULD GENERALLY BE 1-3 INCHES THROUGH THURSDAY MORNING WITH AROUND 6 INCHES IN THE MOUNTAINS. ANOTHER STORM SYSTEM COULD BRING WIDESPREAD ACCUMULATING SNOW SATURDAY AFTERNOON THROUGH SUNDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE REQUIRED THROUGH TONIGHT. NEZ002-003-019>021-054-055-095-096-251115- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX- 411 AM MST TUE FEB 24 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN NEBRASKA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY A STRONG COLD FRONT WILL MOVE SOUTHWARD ACROSS THE REGION ON WEDNESDAY...BRINGING COLD TEMPERATURES AND ANOTHER GOOD CHANCE FOR WIDESPREAD LIGHT SNOWFALL. ACCUMULATIONS SHOULD GENERALLY BE LESS THAN AN INCH THROUGH THURSDAY MORNING. ANOTHER STORM SYSTEM COULD BRING WIDESPREAD ACCUMULATING SNOW SATURDAY AFTERNOON THROUGH SUNDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE REQUIRED THROUGH TONIGHT.
The national radar mosaic for the moment the first event began.
5 winter weather. Local standard time, as filed.
The Brooklyn Lake SNOTEL site (elevation 10240 ft) estimated six inches of snow.
The North French Creek SNOTEL site (elevation 10130 ft) estimated 7.5 inches of snow.
The Medicine Bow SNOTEL site (elevation 10500 ft) estimated 9 inches of snow.
The Sand Lake SNOTEL site (elevation 10050 ft) estimated 10 inches of snow.
The Crow Creek SNOTEL site (elevation 8330 ft) estimated 6 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2015Every state in 2015This day in weather historyWarnings in Wyoming, February 2015
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: 561475, 561476, 561477, 561478, 561479.