A Pacific upper level trough moved onshore with low level gradients for synoptic lift and strong flow aloft at 700 mb. Rapid cyclogenesis with several hundreds worth of CAPE contributed to strong and severe thunderstorms moving across the region producing thunderstorm winds in excess of 60 mph and tree limbs broken or uprooted.
Every event with a place to put it. 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 upper level trough moved onshore with low level gradients for synoptic lift and strong flow aloft at 700 mb. Rapid cyclogenesis with several hundreds worth of CAPE contributed to strong and severe thunderstorms moving across the region producing thunderstorm winds in excess of 60 mph and tree limbs broken or uprooted.
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 26, 10:46 AM MST, 3 hours 35 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 1146 AM MDT Fri Apr 26 2019 .SHORT TERM...(Today through Sunday) Issued at 310 AM MDT Fri Apr 26 2019 The main forecast concerns through this weekend will be strong gusty winds later today/tonight and thunderstorms later today in addition to Sunday. Current IR Satellite loop shows the next Pacific upper level trough pushing onshore over the next few hours along the Washington coast. This trough will then dig southeast into Wyoming later today, but is trending a little slower compared to previous model runs from yesterday. Low level gradients are also not quite as impressive with more synoptic lift compared to 24 hours ago. Most models struggle to show 50 to 55 knots of 700mb flow, which comes in near or just after sunset. Rapid cyclogenesis is still expected to take place over east central Wyoming and around the Nebraska/South Dakota/Wyoming border late this afternoon with rapid pressure falls, so windy conditions are still expected but widespread High Wind Warning criteria are unlikely at this time. What is more concerning is high res models showing a decent coverage of convection by late this afternoon with multicells and a few linear squall lines driven by outflow winds. Given how potent the upper level jet streak is with this system, do believe high res models are onto something. Although only a few places may see environmental winds near High Wind criteria, we believe there is a greater chance for thunderstorm winds to peak over 60 to 65 mph late this afternoon through this evening. Thunderstorms may even continue to develop after sunset once the main trough rolls through the area. Will likely need a statement regarding severe thunderstorm wind gusts this morning, even though prevailing/environmental winds will certainly play a roll in this as well. Based on current models, maximum pressure gradient and winds just off the surface will not get here until around or just after sunset with a core of high winds across east central Wyoming and most of western Nebraska. Given the lack of Boundary Layer mixing by that time, convection will need to bring some of these winds down to the surface. Once the thunderstorms and the wind eventually end tonight, models indicate a pleasant day Saturday with highs generally in the 60s. Winds will gradually decrease through the morning hours, but will increase again in the afternoon across southeast Wyoming, but should not be quite as strong compared to later today. Expect dry conditions with mostly sunny skies for weekend outdoor activities. For Sunday, models show the next cold front which will be quite strong for this time of the year. All models show 700mb temperatures as low as -12c to -14c behind this front across Montana, Idaho, and Washington state early Sunday morning. This front and associated upper level low will need to be watched through the weekend since snowfall is possible. For Sunday, most of the region should be ahead of the cold front where a good chance for rain showers and thunderstorms exist, especially along the Interstate 80 corridor through the afternoon. Depending on the exact timing of the front, expect highs around 70 degrees for far southeast Wyoming and southern Nebraska with temperatures cooling off into the 50s further north. .LONG TERM...(Sunday night through Thursday) Issued at 211 AM MDT Fri Apr 26 2019 Sunday night/Monday...As a progressive shortwave trough aloft moves eastward across the Dakotas, a strong cold front will sweep across our counties, ushering in much cooler air for Monday with high temperatures only in the 40s. Moist upslope will produce plenty of cloud cover with a chance of mainly snow showers Monday afternoon along the Colorado state line. Tuesday...Another shortwave trough aloft will sweep across northern Colorado, spreading scattered to numerous showers, and isolated thunderstorms, across our counties. Temperatures will remain quite cool with abundant cloud cover and precipitation. Wednesday...A secondary shortwave trough aloft will move across northern Wyoming spreading scattered showers across our counties, though with low level downslope winds limiting shower coverage to the lee of the I-25 corridor and southern Laramie Range. Thursday...Temperatures will slowly warm with less cloud cover and warming mid level temperatures. A few showers may persist in the cyclonic flow aloft, though most locations will remain dry. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1142 AM MDT Fri Apr 26 2019 A strong area of low pressure and cold front will move from northwest to southeast this afternoon moving across the area. Thunderstorms will be likely along with gusty winds through the remainder of the taf period. Added mention of showers or storms to all terminals based on the latest hi-res guidance. Expect a line of storms with gusty winds to move through between 21 and 0200z. Low freezing levels will likely lead to hail generation and icing conditions in and around thunderstorms/showers. Expect gusty winds upwards of 40kts with storms this afternoon and cloud tops near FL350 with the strongest storms. Aviators use caution in and around thunderstorms and terrain as gusty and erratic winds are expected. && .FIRE WEATHER... Issued at 229 AM MDT Fri Apr 26 2019 Daytime minimum relative humidities will lower into the 20s Friday and Saturday afternoon with windy conditions expected. Will need to monitor dewpoint trends over the next 48 hours in the event that elevated Fire Weather concerns are possible. Otherwise, a strong cold front will move into the area Sunday and Sunday night resulting in a prolonged period of cooler temperatures and higher humidities for most of next week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && SHORT TERM...TJT LONG TERM...RUBIN AVIATION...AL FIRE WEATHER...TJT
Hazardous Weather Outlook National Weather Service Cheyenne WY 405 AM MDT Fri Apr 26 2019 NEZ002-003-095-096-WYZ101>119-271015- Dawes-Box Butte-North Sioux-South Sioux- 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- 405 AM MDT Fri Apr 26 2019 This hazardous weather outlook is for the northwestern Nebraska panhandle and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Showers and thunderstorms will develop by mid to late afternoon and rapidly push east across southeast Wyoming and into western Nebraska. Some of these thunderstorms may contain very strong wind gusts over 55 to 65 mph into this evening. Very windy conditions are expected through midnight tonight. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY Another round of thunderstorms are possible on Sunday before a strong cold front pushes across the area late Sunday and Sunday night. Some snowfall is possible Monday and Tuesday across southeast Wyoming. .Spotter information statement... Spotters are urged to report sudden strong wind gusts to the National Weather Service. NEZ019>021-054-055-271015- Scotts Bluff-Banner-Morrill-Kimball-Cheyenne- 405 AM MDT Fri Apr 26 2019 This hazardous weather outlook is for the southwestern Nebraska panhandle. .DAY ONE...TODAY AND TONIGHT Showers and thunderstorms will develop by late afternoon and rapidly push east into western Nebraska. Some of these thunderstorms may contain gusty winds and small hail. Very windy conditions with northwest winds gusting between 40 to 50 mph are expected through midnight tonight and early Saturday morning. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY Another round of thunderstorms are possible on Sunday before a strong cold front pushes across the area late Sunday and Sunday night. .Spotter information statement... Spotter activation will not be required at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
238 PM MDT FRI APR 26 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0150 PM NON-TSTM WND GST 8 W ELK MOUNTAIN 41.69N 106.57W
04/26/2019 M58 MPH CARBON WY MESONET
STRONG WIND GUSTS RECORDED AT HALLECK RIDGE ON I-80 WEST
OF ELK MOUNTAIN.
&&
JGPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
243 PM MDT FRI APR 26 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0228 PM TSTM WND GST 20 N WHEATLAND 42.34N 104.96W
04/26/2019 M58 MPH PLATTE WY MESONET
STRONG WIND GUSTS RECORDED AT COLEMAN NORTH OF WHEATLAND.
&&
JGPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
302 PM MDT FRI APR 26 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0227 PM TSTM WND DMG WHEATLAND 42.05N 104.96W
04/26/2019 PLATTE WY BROADCAST MEDIA
A SMALL TOWER WAS BLOWN DOWN AT KYCN RADIO. WINDS IN
EXCESS OF 60 MPH WERE ESTIMATED BY RADIO STATION STAFF.
&&
JGPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
310 PM MDT FRI APR 26 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0252 PM NON-TSTM WND GST ESTERBROOK 42.41N 105.36W
04/26/2019 E61 MPH CONVERSE WY MESONET
&&
ALYONSSpecial Weather Statement
National Weather Service Cheyenne WY
310 PM MDT FRI APR 26 2019
WYZ103>106-109>117-262200-
Shirley Basin WY-Upper North Platte River Basin WY-
North Snowy Range Foothills WY-North Laramie Range WY-
Central Carbon County WY-Laramie Valley WY-South Laramie Range WY-
Central Laramie Range and Southwest Platte County WY-
Sierra Madre Range WY-Ferris/Seminoe/Shirley Mountains WY-
South Laramie Range Foothills WY-Southwest Carbon County WY-
Snowy Range WY-
310 PM MDT FRI APR 26 2019
...SIGNIFICANT WEATHER ADVISORY FOR CARBON...ALBANY AND SOUTH CENTRAL
CONVERSE COUNTIES UNTIL 400 PM MDT...
At 308 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 14 miles west of Battle Mountain to near
Arlington to near Skyline. Movement was east at 60 mph.
Wind gusts of 50 to 55 mph will be possible with these storms.
Locations impacted include...
Laramie, Rawlins, Albany, Saratoga, Hanna, Encampment, Baggs,
Sinclair, Medicine Bow, Rock River, Elk Mountain, Dixon, Battle
Mountain, Grand Encampment, Esterbrook, Six Mile Campground, Friend
Park Campground, Muddy Gap, Teton Reservoir and Savery.
This includes Interstate 80 in Wyoming between mile markers 200 and
312.
LAT...LON 4166 10793 4166 10751 4243 10752 4243 10529
4146 10530 4100 10620 4101 10792
TIME...MOT...LOC 2108Z 283DEG 64KT 4212 10649 4164 10616 4111 10666
BrothersPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
312 PM MDT FRI APR 26 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0252 PM TSTM WND GST 1 N YODER 41.93N 104.29W
04/26/2019 E80 MPH GOSHEN WY PUBLIC
PUBLIC REPORT OF A SIDE BY SIDE FOUR WHEELER BLOWN OVER
RELAYED BY GOSHEN COUNTY EMA.
&&
ALYONSThe Cheyenne radar (KCYS), 119 km away, was scanning. The volume nearest the first event began at 21:18 UTC.
6 thunderstorm wind. Local standard time, as filed.
Tree along Sandberg Road was uprooted by thunderstorm winds.
Video of strong winds and report of winds from handheld anemometer were sent to the office from the observer.
Reports of recently plowed fields having dust lifted reducing area visibility in addition to tree limbs being broken off.
Winds measured at the KNEB radio broadcast studio.
Report of winds measured by handheld anemometer relayed by KNEB staff to office.
Report relayed by KNEB of handheld anemometer measurement of winds.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2019Every state in 2019This day in weather historyWarnings in Nebraska, April 2019
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: 810053, 810050, 810051, 810052, 810054, 810056.