A low pressure system tracked across Colorado. Rain changed to snow, with moderate to heavy snowfall observed.
Every event with a place to put it; 33 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 low pressure system tracked across Colorado. Rain changed to snow, with moderate to heavy snowfall observed. Gusty northerly winds to 25 mph produced areas of blowing snow with poor visibilities. Snow totals varied from a half foot to two feet, heaviest over the mountains.
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 Apr 25, 10:22 PM MST, 1 hour 38 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1122 PM MDT MON APR 25 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 418 PM MDT MON APR 25 2016
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER HIGHER
ELEVATIONS OF SOUTHEAST WYOMING THIS AFTERNOON. WHILE THE SEVERE
THUNDERSTORM THREAT IS LOW...THERE MAY BE ENOUGH CAPE FOR A FEW
MARGINALLY SEVERE THUNDERSTORMS OVER FAR SOUTHEAST WYOMING. THE
MAIN POTENTIAL FOR ANY SEVERE THUNDERSTORMS WILL BE LATE THIS
AFTERNOON THROUGH EARLY EVENING. THE MAIN QUESTION IS IF STORM
UPDRAFTS CAN BE SUSTAINED GIVEN THAT STRONG ELEVATED SHEAR MAY
RIP THE UPDRAFTS APART. LATE THIS EVENING BOTH THE THUNDERSTORM
THREAT AND SEVERE THREAT WILL WANE...BUT A FEW ELEVATED
THUNDERSTORMS MAY LINGER ACROSS THE SOUTHERN NEBRASKA PANHANDLE AS
STRONG THETAE ADVECTION WILL BE IN PLACE.
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST WYOMING WILL
TRANSITION TO A STRATIFORM TYPE PRECIPITATION INTO THE OVERNIGHT
HOURS WITH WIDESPREAD RAIN AND SNOW LATE TONIGHT INTO TOMORROW.
SNOW LEVELS WILL MAINLY BE ABOVE 6500 FEET BUT SNOW LEVELS INTO
CONVERSE COUNTY MAY DROP TO AROUND 5000 FEET TONIGHT AS THERE IS
SLIGHTLY COOLER AIR IN PLACE OVER THAT AREA...AND ALSO
PRECIPITATION DRAG FROM HIGHER PRECIPITATION RATES SHOULD LOWER
THE SNOW LEVEL. A WINTER STORM WARNING IS IN EFFECT LATE TONIGHT
THROUGH TUESDAY EVENING.
A WINTER WEATHER ADVISORY MAY EVENTUALLY BE NEEDED FOR LOWER
ELEVATIONS WEST OF THE LARAMIE RANGE. AT THIS TIME SNOW AMOUNTS
WILL BE MARGINAL FOR AN ADVISORY AND MOST SNOW THAT FALLS WILL
LIKELY MELT ON CONTACT WITH THE GROUND...SO IMPACTS SHOULD BE
MINIMAL. OF COURSE IF TEMPERATURES ARE ONLY A FEW DEGREES COOLER
THAN THE CURRENT FORECAST THEN HIGHER ACCUMULATIONS WOULD
OCCUR...SO SOMETHING TO KEEP AN EYE ON.
THE NEXT QUESTION IS WHAT HAPPENS TUESDAY NIGHT THROUGH WEDNESDAY.
THE MODELS DIVERGE GREATLY ON HOW THE UPPER LEVEL TROUGH
EVOLVES. NOT CONFIDENT IN ANY ONE MODEL AT THIS TIME BUT SHOULD
THE GFS VERIFY THEN HEAVY SNOW WOULD OCCUR ALONG THE PINE RIDGE
AND THE PLAINS OF SOUTHEAST WYOMING TUESDAY NIGHT. THE NAM AND
ECMWF ARE SHOWING COMPLETELY DIFFERENT SOLUTIONS WITH LITTLE TO NO
SNOW ACCUMULATION EXPECTED TUESDAY NIGHT. HOPEFULLY THE 00Z MODEL
RUNS SHOW A BETTER CONSENSUS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 418 PM MDT MON APR 25 2016
COOL AND UNSETTLED PATTERN WILL DOMINATE MUCH OF THE EXTENDED
PERIOD. WIDESPREAD LOW CLOUDS WILL DEVELOP BY WED NIGHT AND THURS
MORNING AS LLVL UPSLOPE STRENGTHENS TO THE EAST OF THE LARAMIE
RANGE. BOTH THE GFS AND ECMWF SHOW A SHORTWAVE DIGGING INTO THE
DESERT SOUTHWEST BY THURS AND THEN LIFTING NORTHEAST INTO COLORADO
BY FRI. DEEP LAYER ASCENT INCREASES OVER THE PLAINS ON FRI WITH
WIDESPREAD STRATIFORM PRECIP. THE SNOW LEVEL CURRENTLY LOOKS TO BE
AROUND 6500 FT WITH THIS EVENT. IT WILL REMAIN COOL AND SHOWERY
THROUGH THE WEEKEND WITH A LARGE SCALE UPPER TROUGH OVER WY. NOT
EXPECTING ANY WINDY CONDITIONS THROUGH THE WEEKEND WITH RATHER WEAK
SFC PRESSURE GRADIENTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 1122 PM MDT MON APR 25 2016
MVFR/LCL IFR CONDITIONS EXPECTED ACROSS THE WY TERMINALS FOR MUCH OF
THE PERIOD WITH RAIN AND SNOW MAINLY BEFORE 18Z. VFR ACROSS THE NEB
PANHANDLE EXPECTED TO LOWER TO IFR CIGS BY 12Z IN MOIST UPSLOPE FLOW
THEN IMPROVE A BIT TO MVFR IN THE AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 340 PM MDT MON APR 25 2016
A VERY MOIST WEATHER PATTERN WILL CONTINUE INTO NEXT WEEK.
CRITICAL FIRE WEATHER IS NOT EXPECTED DURING THIS TIME.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT MDT
TUESDAY NIGHT FOR WYZ101-103>105-112-114-116.
NE...NONE.
&&
SHORT TERM...SML
LONG TERM...ZF
AVIATION...ER
FIRE WEATHER...SMLHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 1151 AM MDT MON APR 25 2016 WYZ101>105-109>115-261800- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- NORTH LARAMIE RANGE-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- 1151 AM MDT MON APR 25 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WYOMING...SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE AREA THIS AFTERNOON INTO EARLY THIS EVENING. SEVERE STORMS ARE NOT EXPECTED. SNOW WILL DEVELOP OVER THE MOUNTAINS OF SOUTHEAST WYOMING THIS EVENING WITH PERIODS OF HEAVY SNOW EXPECTED THROUGH TONIGHT. SNOW LEVELS MAY DROP TO 7000 FEET BY LATE TONIGHT BUT MOST ACCUMULATIONS WILL OCCUR ABOVE 8000 FEET. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY PERIODS OF SNOW WILL CONTINUE ACROSS THE MOUNTAINS OF SOUTHEAST WYOMING TUESDAY AND INTO WEDNESDAY NIGHT AS A SLOW MOVING AREA OF LOW PRESSURE MOVES ACROSS THE CENTRAL ROCKIES. ACCUMULATING SNOW WILL LIKELY SPREAD INTO THE PLAINS OF SOUTHEAST WYOMING BY TUESDAY NIGHT WITH PERIODS OF SNOW POSSIBLE INTO WEDNESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. NEZ002-003-021-055-095-096-261800- DAWES-BOX BUTTE-MORRILL-CHEYENNE-NORTH SIOUX-SOUTH SIOUX- 1151 AM MDT MON APR 25 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF PANHANDLE NEBRASKA. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE AREA THIS AFTERNOON INTO EARLY THIS EVENING. SEVERE STORMS ARE NOT EXPECTED. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A SLOW MOVING AREA OF LOW PRESSURE WILL BRING RAIN AND SNOW TO THE NEBRASKA PANHANDLE TUESDAY INTO WEDNESDAY NIGHT. ALTHOUGH THERE IS STILL MUCH UNCERTAINTY TO THE TRACK OF THIS LOW PRESSURE SYSTEM...SNOW IS POSSIBLE ALONG HIGHER ELEVATIONS SUCH AS THE PINE RIDGE. THE MAIN CHANCES FOR SNOW SHOULD BE WEDNESDAY NIGHT BUT SOME ACCUMULATIONS MAY OCCUR AS EARLY AS TUESDAY NIGHT ALONG THE PINE RIDGE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. NEZ019-020-054-WYZ106>108-116>119-261800- SCOTTS BLUFF-BANNER-KIMBALL- 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- 1151 AM MDT MON APR 25 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF PANHANDLE NEBRASKA AND SOUTHEAST WYOMING. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE AREA THIS AFTERNOON INTO EARLY THIS EVENING. A FEW THUNDERSTORMS MAY BECOME SEVERE OVER FAR SOUTHEAST WYOMING AND SOUTHERN PORTIONS OF THE NEBRASKA PANHANDLE. THE MAIN SEVERE THUNDERSTORM THREAT IS FOR HAIL TO THE SIZE OF QUARTERS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A SLOW MOVING AREA OF LOW PRESSURE WILL LIKELY PRODUCE SNOW ACROSS THE PLAINS OF SOUTHEAST WYOMING TUESDAY NIGHT WITH PERIODS OF SNOW POSSIBLE INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR PERIODS OF HEAVY SNOW...ESPECIALLY AT ELEVATIONS ABOVE 5000 FEET. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON THROUGH EARLY THIS EVENING.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
713 PM MDT MON APR 25 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0710 PM HAIL 14 NW ALBIN 41.56N 104.29W
04/25/2016 E0.25 INCH LARAMIE WY TRAINED SPOTTER
SMALL HAIL WITH HEAVY RAIN. WINDS HAVE PICKED UP.
&&
BCHAPMANPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
718 PM MDT MON APR 25 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0714 PM HAIL 9 SE WHEATLAND 41.96N 104.84W
04/25/2016 E0.25 INCH PLATTE WY TRAINED SPOTTER
1 IN OF SMALL HAIL COVERS THE GROUND
&&
BCHAPMANPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
813 PM MDT MON APR 25 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0811 PM HAIL 9 SW GERING 41.74N 103.79W
04/25/2016 E0.50 INCH SCOTTS BLUFF NE TRAINED SPOTTER
&&
BCHAPMANPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
839 PM MDT MON APR 25 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0838 PM HAIL GERING 41.83N 103.67W
04/25/2016 E0.25 INCH SCOTTS BLUFF NE TRAINED SPOTTER
VERY HEAVY RAIN. ESTIMATE 40 MPH WINDS
&&
BCHAPMANSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 1209 AM MDT TUE APR 26 2016 NEZ020-054-WYZ119-260700- KIMBALL NE-BANNER NE-EAST LARAMIE COUNTY WY- 1209 AM MDT TUE APR 26 2016 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN BANNER...WESTERN KIMBALL AND EASTERN LARAMIE COUNTIES UNTIL 100 AM MDT... AT 1208 AM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR PANORAMA POINT...OR 25 MILES SOUTHWEST OF KIMBALL...MOVING NORTH AT 45 MPH. HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... PINE BLUFFS...ALBIN...OLIVER CAMPGROUND...GUN BARREL...PANORAMA POINT AND BUSHNELL. THIS INCLUDES THE FOLLOWING HIGHWAYS... INTERSTATE 80 IN WYOMING BETWEEN MILE MARKERS 388 AND 402. INTERSTATE 80 IN NEBRASKA BETWEEN MILE MARKERS 1 AND 12. PRECAUTIONARY/PREPAREDNESS ACTIONS... FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE SHELTER INSIDE A BUILDING OR VEHICLE. THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. && LAT...LON 4153 10436 4159 10374 4100 10386 4101 10432 TIME...MOT...LOC 0608Z 184DEG 48KT 4107 10410 TJT
The national radar mosaic for the moment the first event began.
33 winter storm. Local standard time, as filed.
The Battle Mountain SNOTEL site (elevation 7440 ft) estimated 19 inches of snow.
The Sage Creek Basin SNOTEL site (elevation 7850 ft) estimated 13 inches of snow.
The Divide Peak SNOTEL site (elevation 8880 ft) estimated 16 inches of snow.
The Old Battle SNOTEL site (elevation 10000 ft) estimated 18 inches of snow.
The Webber Springs SNOTEL site (elevation 9250 ft) estimated 13 inches of snow.
The Little Snake River SNOTEL site (elevation 8915 ft) estimated 18 inches of snow.
The Whiskey Park SNOTEL site (elevation 8950 ft) estimated 15 inches of snow.
The South Brush Creek SNOTEL site (elevation 8440 ft) estimated 12 inches of snow.
The North French Creek SNOTEL site (elevation 10130 ft) estimated 22 inches of snow.
The Sand Lake SNOTEL site (elevation 10050 ft) estimated 18 inches of snow.
The Brooklyn Lake SNOTEL site (elevation 10240 ft) estimated 13 inches of snow.
The Cinnabar Park SNOTEL site (elevation 9574 ft) estimated 13 inches of snow.
The Medicine Bow SNOTEL site (elevation 10500 ft) estimated 24 inches of snow.
The Crow Creek SNOTEL site (elevation 8330 ft) estimated 15 inches of snow.
The Windy Peak SNOTEL site (elevation 7900 ft) estimated 12 inches of snow.
Six inches of snow was measured four miles west-southwest of Douglas.
Eight inches of snow was reported at Douglas.
Eight inches of snow was measured at Elk Mountain.
Ten inches of snow was reported two miles southwest of Douglas.
Six inches of snow was reported at Rawlins.
Six and a half inches of snow was measured ten miles north of Cheyenne.
Six inches of snow was reported at Laramie.
Seven inches of snow was measured three miles northeast of Laramie.
A foot of snow was reported two miles north of Centennial.
Six and a half inches of snow was measured near the Laramie Airport.
Six inches of snow was measured eight miles southwest of Wheatland.
Fifteen inches of snow was reported three miles north of Centennial.
Six inches of snow was measured one mile south of Cheyenne.
Ten inches of snow was reported at Arlington.
Six inches of snow was reported at Muddy Gap.
Seven inches of snow was reported at Seminoe Dam.
Eight inches of snow was reported at Medicine Bow.
Six inches of snow was reported at Shirley Basin.
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, April 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: 637996, 638007, 638008, 638009, 638010, 638011, 638013, 638019, 638020, 638022, 638023, 638035, 638036, 638038, 638039, 638136, 638137, 638138, 638139, 638140, 638141, 638142, 638143, 638144, 638145, 638146, 638147, 638148, 638149, 638151, 638152, 638154, 638155.