Strong to severe thunderstorms moved across the Nebraska Panhandle producing large hail with damaging winds in excess of 65 mph being the bigger impact to communities. Winds were strong enough to knock down several large tree branches in addition to toppling a recreational vehicle in a camper park.
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.
Strong to severe thunderstorms moved across the Nebraska Panhandle producing large hail with damaging winds in excess of 65 mph being the bigger impact to communities. Winds were strong enough to knock down several large tree branches in addition to toppling a recreational vehicle in a camper park. Several weather stations across the area also measured these thunderstorm winds with several in excess of 60 mph.
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 Aug 20, 9:07 PM MST, 20 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 1007 PM MDT Tue Aug 20 2019 .UPDATE... Issued at 308 PM MDT Tue Aug 20 2019 A Severe Thunderstorm Watch was just issued for far east southeast Wyoming and the western Nebraska Panhandle. Please see the Watch for further details. && .SHORT TERM...(This evening through Wednesday) Issued at 211 PM MDT Tue Aug 20 2019 A potent shortwave will dig south and west over the region this afternoon and evening, pushing a cold front up against the the east side of the Laramie Range. This will bring rich low level moisture into the I-25 corridor, with dewpoints across east Laramie County and southern Platte County already in the mid to upper 50s. Moisture is just one of the factors that will allow for today's thunderstorm development. Other triggers for our late day and nocturnal convection include MLCAPE between 3000 to 4000 J/kg along and east of I-25 and 0-6 bulk shear between 35 to 45 knots. With these values in mind, discrete supercells will be possible, especially in today's early stages of development. However, by tonight, storm development will be largely linear, likely in the infancy stage of MCS development as the storms moves east and out of the western most portion of the Nebraska Panhandle. The other factor to note here is the helicity values, which will be above 40 kts, generally north of the I-80 corridor. This factor in combination with relatively low LCLs leads me to believe that a tornado or two cannot be ruled out during this round of storms. Already seeing some development as of 230 PM MDT near Lusk, with more development expected across southeast Wyoming in the next few hours. Storms will really get going around and after 5 PM MDT, becoming widely scattered soon afterwards. Storms will move from northwest to southeast, and with slow storm motion forecast, heavy rain that could lead to flash flooding, will be something to look out for. Storms will finally move east and out of the far-west Nebraska Panhandle around 3 AM MDT. Besides heavy rain and potential flash flooding concerns, threats include large hail up to 2 inches, damaging winds, and frequent lightning. A tornado or two cannot be ruled out. Another round of thunderstorms are forecast Wednesday as moisture gets pulled northward with the expected upslope winds. This could cause areas of fog along I-80, though there could also be areas of fog in the early morning hours where heavy rain falls overnight. Cooler temperatures are forecasts for tomorrow, with highs in the mid 70s and 80s. Strong and severe thunderstorms are forecast again under another potent upper level shortwave, through they may be limited my the cooler weather. .LONG TERM...(Thursday through next Monday night) Issued at 335 AM MDT Tue Aug 20 2019 Models continue to be in reasonable agreement through the weekend, and are now coming into better agreement regarding a pretty strong cold front for the last week of August arriving sometime next week. Models continue to show the slow moving Pacific upper level trough pushing east across Montana and northern Wyoming Thursday and Thursday night. The GFS and Canadian are the slowest and show a decent chance of thunderstorms across the mountains and the eastern plains through the day and into the evening hours. Decided to increase POP a bit for these areas into Thursday evening. Thankfully, shear looks marginal so the severe weather threat is pretty low. Once this Pacific system moves east, all models show drier weather across the area during the weekend along with some pretty warm temperatures in the 80s to low 90s. May need to increase high temperatures even more on Sunday with most models showing 700mb temperatures above 16c-18c. Further out, all models are showing a strong cold front moving into the Pacific NW and the northern plains, with 700mb temperatures dropping to near zero early to mid next week. However, models are not in good agreement regarding the timing of this front with the ECMWF 18 hours later than the GFS and the Canadian is even later than that. In addition, some models are showing some pretty cold 700mb temperatures behind this front, with values as low as -5 across northern Wyoming and Montana. This bares watching as there is reasonable agreement with the ensemble forecasts 7 to 9 days out. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1003 PM MDT Tue Aug 20 2019 Wyoming TAFS...VFR at Rawlins. VFR at Laramie. Wind gusts to 25 knots from 15Z to 01Z. VFR at Cheyenne until 09Z, then MVFR until 15Z, then VFR. Nebraska TAFS...VFR at Chadron and Alliance until 08Z, then MVFR until 15Z, then VFR. VFR at Scottsbluff and Sidney until 08Z, then MVFR until 15Z, then VFR. Wind gusts to 23 knots from 15Z to 19Z. && .FIRE WEATHER... Issued at 211 PM MDT Tue Aug 20 2019 Another hot and dry day west of the Laramie Range, with winds just below the critical threshold. To the east of the Laramie Range, scattered to widely scattered thunderstorms, some strong to severe, will affect the area. A few isolated dry thunderstorms may make it as far west as FWZ 308; this threat will mostly end by 2000 MDT. Haines Index remains at 6 across Carbon County and will remain at this level through the week. Winds will decrease Wednesday, increasing for Thursday as a ridge of high pressure pushes into the region from the west. A Fire Weather Watch may be needed for Thursday across areas west of the Laramie Range. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && UPDATE...AB SHORT TERM...AB LONG TERM...TJT AVIATION...RUBIN FIRE WEATHER...AB
Hazardous Weather Outlook National Weather Service Cheyenne WY 307 PM MDT Tue Aug 20 2019 NEZ002-003-019>021-054-055-095-096-WYZ101-102-107-108-117>119- 212115- Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne- North Sioux-South Sioux-Converse County Lower Elevations- Niobrara County-East Platte County-Goshen County- South Laramie Range Foothills-Central Laramie County- East Laramie County- 307 PM MDT Tue Aug 20 2019 This hazardous weather outlook is for portions of western Nebraska...east central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Strong to severe thunderstorms likely today with the biggest concern being large hail up to 2 inches in diameter. A Severe Thunderstorm Watch is in effect until 11 PM MDT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY Severe storms are again possible on Wednesday and then afternoon thunderstorm chances continue into the weekend. .Spotter information statement... Spotter activation is needed today. WYZ103>106-109>116-212115- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte 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- 307 PM MDT Tue Aug 20 2019 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Isolated thunderstorms possible along with a few dry thunderstorms along and near the Laramie Range. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY Isolated thunderstorm chances will continue through Monday. Fire weather concerns increase on Thursday west of the Laramie Range. .Spotter information statement... Spotter activation will not be needed.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
734 PM MDT TUE AUG 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0715 PM FLASH FLOOD 10 SW WHEATLAND 41.95N 105.10W
08/20/2019 PLATTE WY STORM CHASER
RAPID FLOWING WATER AND HAIL DRIFTS ALONG ROAD 34 AND IN
PASTURE LAND. DAN FITTS RELAYED VIA TWITTER.
&&
GCLAYCOMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
748 PM MDT TUE AUG 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0634 PM HAIL 10 SW WHEATLAND 41.95N 105.10W
08/20/2019 M2.50 INCH PLATTE WY STORM CHASER
STORM CHASER MEASURED TENNIS BALL SIZED HAIL. HWY 34 MM42
NEAR SYBILLE CREEK.
&&
WILLSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
750 PM MDT TUE AUG 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0740 PM FLASH FLOOD 8 W WHEATLAND 42.05N 105.11W
08/20/2019 PLATTE WY TRAINED SPOTTER
REPORTS INTERSECTION OF PALMER CANYON ROAD AND COONEY
HILLS UNDER FLOWING WATER.
&&
GCLAYCOMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
939 PM MDT TUE AUG 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0936 PM FLASH FLOOD 10 SW WHEATLAND 41.95N 105.10W
08/20/2019 PLATTE WY EMERGENCY MNGR
DEADHEAD CREEK ROAD FLOODED WITH WATER FLOWING INTO
SYBILLE CREEK. SYBILLE CREEK RUNNING VERY HIGH.
&&
GCLAYCOMSpecial Weather Statement National Weather Service Cheyenne WY 942 PM MDT Tue Aug 20 2019 WYZ106>108-210445- East Platte County WY- Central Laramie Range and Southwest Platte County WY- Goshen County WY- 942 PM MDT Tue Aug 20 2019 ...SIGNIFICANT WEATHER ADVISORY FOR WESTERN GOSHEN AND EAST CENTRAL PLATTE COUNTIES UNTIL 1045 PM MDT... At 942 PM MDT, Doppler radar was tracking a strong thunderstorm over Wheatland, moving east at 10 mph. Pea size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Wheatland, Guernsey, Grayrocks Reservoir, Chugcreek, Lakeview North and Y-O Ranch. This includes Interstate 25 in Wyoming between mile markers 74 and 83. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for southeastern Wyoming. LAT...LON 4196 10500 4209 10503 4226 10475 4201 10461 TIME...MOT...LOC 0342Z 248DEG 10KT 4205 10497 Worley
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
944 PM MDT TUE AUG 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0937 PM FLASH FLOOD 9 SW WHEATLAND 41.96N 105.08W
08/20/2019 PLATTE WY EMERGENCY MNGR
HIGHWAY 34 FLOODED BETWEEN DEADHEAD CREEK ROAD AND MILE
MARKER 43.
&&
GCLAYCOMThe Cheyenne radar (KCYS), 121 km away, was scanning. The volume nearest the first event began at 04:26 UTC.
11 thunderstorm wind, 1 hail. Local standard time, as filed.
Photos received showing a large recreation vehicle trailer blown over at the Roddoux RV park.
Winds measured at the KNEB weather station with noted tree damage surrounding the studio.
Observer estimated the reported wind gusts using handheld anemometer.
Observer estimated the winds based on the area surroundings reacting to the thunderstorm winds.
Several large diameter tree branches were reported knocked down.
Sensor at the Scotts Bluff Airport measured the recorded wind speeds.
KNEB weather station measured the recorded wind speed with nearby extensive tree damage.
Multiple trees were knocked down from thunderstorm winds blocking roadway access along several area roads.
Thunderstorm winds measured by a KNEB automated weather station.
Thunderstorm winds measured by a KNEB automated weather station.
Thunderstorm winds measured by a KNEB automated weather station.
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, August 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: 842515, 842516, 842517, 842518, 842519, 842520, 842521, 843917, 842523, 842524, 842525, 842526.