A upper level low pressure system and moist low level upslope flow produced heavy snowfall over the Snowy and Sierra Madre mountains. Visibilities were reduced to a quarter mile in heavy snow.
Every event with a place to put it; 5 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 upper level low pressure system and moist low level upslope flow produced heavy snowfall over the Snowy and Sierra Madre mountains. Visibilities were reduced to a quarter mile in heavy snow. Snow totals ranged from 12 to 20 inches.
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 7, 9:27 PM MST, 2 hours 33 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1027 PM MDT SAT MAY 7 2016
.SHORT TERM...(SUNDAY THROUGH MONDAY)
ISSUED AT 240 PM MDT SAT MAY 7 2016
THE STUBBORN UPPER LEVEL LOW WILL SLOWLY MOVE EAST OF THE FORECAST
AREA BY MONDAY...BUT WILL RESULT IN A CONTINUATION OF THE WET AND
COOL PATTERN THROUGH EARLY NEXT WEEK. HEAVY RAIN THREAT APPEARS TO
BE LOWER AS INSTABILITY WILL BE MARGINAL AT BEST SUNDAY AND MONDAY
AFTERNOON. KEPT SCATTERED THUNDERSTORMS IN THE FORECAST WITH A
CHANCE OF AN ADDITIONAL ONE QUARTER INCH TO ONE HALF INCH OF
RAINFALL...ESPECIALLY ACROSS SOUTHEAST WYOMING WHICH HAVE ALREADY
REPORTED QUITE A BIT OF RAINFALL IN SOME AREAS. EXPECT PERIODS OF
SNOW DOWN TO 7500 FEET EACH MORNING AS THE LOW AND MIDLEVEL COLD
POOL ALOFT ROTATES THROUGH THE AREA. LARAMIE MAY EVEN SEE SOME
RAIN/SNOW MIX EARLY SUNDAY AND EARLY MONDAY MORNING AS WELL BEFORE
SUNRISE. HIGH TEMPERATURES WILL REMAIN BELOW NORMAL ON SUNDAY WITH
READINGS MAINLY IN THE 50S. TEMPERATURES WILL REBOUND A BIT ON
MONDAY...BUT ARE EXPECTED TO LOWER DURING THE MIDDLE OF THE WEEK
AS ANOTHER COLD FRONT MOVES ACROSS THE FORECAST AREA FROM THE
NORTH.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 PM MDT SAT MAY 7 2016
WET AND COOL PATTERN CONTINUES THROUGH EARLY IN THE WEEK AS THE
UPPER LOW SLOWLY MOVES NORTHEAST ACROSS THE REGION AND ANOTHER
PIECE OF ENERGY DRIVES SOUTHEAST OUT OF MONTANA AIDING IN THE
DEVELOPMENT OF DAILY CONVECTION. BY WEDNESDAY THE UPPER TROUGH
MOVES OUT TO THE EAST WITH A DRIER MORE SUBSIDENT TYPE AIRMASS
COMING IN FROM THE WEST...DRYING US OUT A BIT MID TO LATE WEEK
WITH A SLIGHT WARMUP THURSDAY INTO FRIDAY. ON FRIDAY WE SEE A
WEAKENING COLD FRONT MOVE IN FROM THE NORTHEAST AS A 120 KT
JETMAX DRIVES SOUTHEAST ACROSS EASTERN MONTANA AND THE DAKOTAS.
THE FRONT WILL PUSH SLOWLY ACROSS THE LARAMIE RANGE BY FRIDAY
NIGHT...THEREFORE HAVE A CHANCE FOR AFTERNOON THUNDERSTORMS OUT
WEST ACROSS THE HIGHER TERRAIN FRIDAY WITH A SLIGHT CHANCE FOR
THUNDERSTORMS OUT EAST ONTO THE PLAINS GOING INTO LATE FRIDAY
AFTERNOON AND EVENING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1022 PM MDT SAT MAY 7 2016
WYOMING TAFS...OCCASIONAL MVFR AT RAWLINS AND CHEYENNE THROUGH
MID MORNING THEN VFR INTO THE AFTERNOON...WITH PERIODS OF MVFR
IN SHOWERS IN THE AFTERNOON AND EVENING. PERIODS OF MVFR AT
LARAMIE THROUGH 09Z...THEN IFR UNTIL 15Z...THEN VFR INTO THE
EARLY AFTERNOON WITH PERIODS OF MVFR IN SHOWERS IN THE AFTERNOON.
NEBRASKA TAFS...PERIODS OF IFR AND MVFR OVERNIGHT THROUGH MID
MORNING...THEN VFR. LOCALIZED MVFR AT ALLIANCE SUNDAY EVENING.
&&
.FIRE WEATHER...
ISSUED AT 400 AM MDT SAT MAY 7 2016
WET WEATHER PATTERN TO CONTINUE THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK. FOR THE NEAR TERM...NO FIRE WEATHER ISSUES ANTICIPATED.
&&
.HYDROLOGY...
ISSUED AT 400 AM MDT SAT MAY 7 2016
RIVER FLOOD WARNINGS HAVE BEEN ISSUED FOR THE NORTH PLATTE
RIVER FROM NEAR TORRINGTON WYOMING TO MITCHELL INTO SCOTTSBLUFF
COUNTY. MODERATE RIVER FLOODING IS NOW EXPECTED FROM MITCHELL TO
SCOTTSBLUFF DUE TO RECENT HEAVY RAINFALL AND UPSTREAM WATER
RELEASES FROM RESERVOIRS. IN ADDITION...ORIN (UPSTREAM FROM
GLENDO) WILL BE ADDED TO THE WARNING AS WELL DUE TO HEAVY RAINFALL
AND SNOW MELT OVER THE NORTHERN LARAMIE RANGE AND AREAS AROUND
CASPER YESTERDAY. IF THAT WASNT ENOUGH...UPSTREAM RELEASES ON THE
LARAMIE RIVER NEAR GRAYROCKS WILL LIKELY RESULT IN RIVER FLOODING
AT FORT LARAMIE LATER THIS WEEKEND...SO ISSUED A RIVER FLOOD
STATEMENT FOR THE LARAMIE RIVER NEAR FORT LARAMIE AS WELL. WILL
NEED TO CLOSELY MONITOR RIVERS IN THE AREA OVER THE NEXT 24 HOURS
DUE TO HEAVY RAIN AND THE POTENTIAL FOR HEAVY RAINFALL BETWEEN
8000 TO 9500 FEET...WHERE A SNOW PACK STILL EXISTS.
FLASH FLOOD WATCH WILL REMAIN IN PLACE FOR TODAY AND INTO TONIGHT
ACROSS SOUTHEAST WYOMING IN AREAS OF GREATEST COVERAGE AND INTENSITY
OF SHOWERS AND TSTORMS TODAY. LARGE AREA OF HEAVY PRECIPITATION IS
ABOUT TO MOVE NORTHWARD INTO EXTREME SOUTHERN WYOMING OVER THE
NEXT FEW HOURS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL NOON MDT SUNDAY FOR WYZ112-114.
FLASH FLOOD WATCH UNTIL 3 AM MDT SUNDAY FOR WYZ101-103-106>108-
115>119.
NE...NONE.
&&
SHORT TERM...TJT
LONG TERM...JG
AVIATION...RUBIN
FIRE WEATHER...JG
HYDROLOGY...TJT/JGHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE CHEYENNE WY 911 PM MDT SAT MAY 7 2016 NEZ019>021-054-055-WYZ103-106>108-116>119-090315- SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE-NORTH LARAMIE RANGE- CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- EAST PLATTE COUNTY-GOSHEN COUNTY-SOUTH LARAMIE RANGE- SOUTH LARAMIE RANGE FOOTHILLS-CENTRAL LARAMIE COUNTY- EAST LARAMIE COUNTY- 911 PM MDT SAT MAY 7 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF PANHANDLE NEBRASKA AND SOUTHEAST WYOMING. .DAY ONE...TONIGHT SHOWERS AND ISOLATED THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY RAIN...WILL CONTINUE THIS EVENING. SHOWERS WILL GRADUALLY DECREASE IN COVERAGE AND INTENSITY OVERNIGHT. A FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM SUNDAY FOR MUCH OF SOUTHEAST WYOMING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY UNSETTLED WEATHER WILL PERSIST THROUGH MUCH OF NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE REQUIRED TONIGHT. NEZ002-003-095-096-WYZ101-102-090315- DAWES-BOX BUTTE-NORTH SIOUX-SOUTH SIOUX- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- 911 PM MDT SAT MAY 7 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF PANHANDLE NEBRASKA AND EAST CENTRAL WYOMING. .DAY ONE...TONIGHT SHOWERS AND ISOLATED THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY RAIN...WILL CONTINUE THIS EVENING. SHOWERS WILL GRADUALLY DECREASE IN COVERAGE AND INTENSITY OVERNIGHT. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY UNSETTLED WEATHER WILL PERSIST THROUGH MUCH OF NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE REQUIRED TONIGHT. WYZ104-105-109>115-090315- FERRIS/SEMINOE/SHIRLEY MOUNTAINS-SHIRLEY BASIN- CENTRAL CARBON COUNTY-NORTH SNOWY RANGE FOOTHILLS- SOUTHWEST CARBON COUNTY-SIERRA MADRE RANGE- UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE-LARAMIE VALLEY- 911 PM MDT SAT MAY 7 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TONIGHT RAIN WILL CHANGE TO SNOW AS SNOW LEVELS FALL TO AROUND 7000 FEET. MODERATE TO OCCASIONALLY HEAVY SNOW WILL CONTINUE FOR ELEVATIONS ABOVE 9000 FEET. A WINTER WEATHER ADVISORY REMAINS IN EFFECT THROUGH SUNDAY MORNING FOR THE SNOWY AND SIERRA MADRE MOUNTAINS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY UNSETTLED WEATHER WILL PERSIST THROUGH MUCH OF NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE REQUIRED TONIGHT.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
916 PM MDT SAT MAY 07 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM SNOW 10 WSW ENCAMPMENT 41.15N 106.97W
05/07/2016 E3.0 INCH CARBON WY OTHER FEDERAL
OLD BATTLE SNOTEL IN THE SIERRA MADRE RANGE. ELEVATION
10000 FEET. SNOW WATER EQUIVALENT IS 0.3 INCHES AND THE
SNOW TO LIQUID RATIO USED WAS 10 TO 1. ACCUMULATION WAS
OVER PAST 6 HOURS.
0600 PM SNOW 8 WSW ENCAMPMENT 41.16N 106.94W
05/07/2016 E3.0 INCH CARBON WY OTHER FEDERAL
WEBBER SPRINGS SNOTEL IN THE SIERRA MADRE RANGE.
ELEVATION 9250 FEET. SNOW WATER EQUIVALENT IS 0.3 INCHES
AND THE SNOW TO LIQUID RATIO USED WAS 10 TO 1.
ACCUMULATION WAS OVER PAST 6 HOURS.
0600 PM SNOW 11 SSE ENCAMPMENT 41.06N 106.71W
05/07/2016 E3.0 INCH CARBON WY OTHER FEDERAL
WHISKEY PARK SNOTEL IN THE SIERRA MADRE RANGE. ELEVATION
8950 FEET. SNOW WATER EQUIVALENT IS 0.3 INCHES AND THE
SNOW TO LIQUID RATIO USED WAS 10 TO 1. ACCUMULATION WAS
OVER PAST 6 HOURS.
0600 PM SNOW 12 W CENTENNIAL 41.30N 106.34W
05/07/2016 E8.0 INCH CARBON WY OTHER FEDERAL
NORTH FRENCH CREEK SNOTEL IN THE SNOWY RANGE. ELEVATION
10130 FEET. SNOW WATER EQUIVALENT IS 0.8 INCHES AND THE
SNOW TO LIQUID RATIO USED WAS 10 TO 1. ACCUMULATION WAS
OVER PAST 6 HOURS.
0600 PM SNOW 10 SSW ARLINGTON 41.46N 106.28W
05/07/2016 E7.0 INCH CARBON WY OTHER FEDERAL
SAND LAKE SNOTEL IN THE SNOWY RANGE. ELEVATION 10050
FEET. SNOW WATER EQUIVALENT IS 0.7 INCHES AND THE SNOW TO
LIQUID RATIO USED WAS 10 TO 1. ACCUMULATION WAS OVER PAST
6 HOURS.
0600 PM SNOW 21 SSE ELK MOUNTAIN 41.41N 106.26W
05/07/2016 E7.0 INCH CARBON WY OTHER FEDERAL
MEDICINE BOW SNOTEL IN THE SNOWY RANGE. ELEVATION 10500
FEET. SNOW WATER EQUIVALENT IS 0.7 INCHES AND THE SNOW TO
LIQUID RATIO USED WAS 10 TO 1. ACCUMULATION WAS OVER PAST
6 HOURS.
&&
MJAMSKIThe national radar mosaic for the moment the first event began.
5 winter storm. Local standard time, as filed.
The Webber Springs SNOTEL site (elevation 9250 ft) estimated 15 inches of snow.
The Whiskey Park SNOTEL site (elevation 8950 ft) estimated 12 inches of snow.
The North French Creek SNOTEL site (elevation 10130 ft) estimated 18 inches of snow.
The Sand Lake SNOTEL site (elevation 10050 ft) estimated 13 inches of snow.
The Medicine Bow SNOTEL site (elevation 10500 ft) estimated 20 inches of snow.
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, May 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: 643117, 643118, 643119, 643120, 643121.