The derecho that was moving through southeast Wyoming and northeast Colorado continued across the Nebraska Panhandle with severe and significant wind gusts. Received numerous reports of sheds blown over, metal roofs ripped off outbuildings, and large trees 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.
The derecho that was moving through southeast Wyoming and northeast Colorado continued across the Nebraska Panhandle with severe and significant wind gusts. Received numerous reports of sheds blown over, metal roofs ripped off outbuildings, and large trees uprooted. Two injuries were reported as metal siding was blown across a highway striking two motorcyclists.
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 Jun 6, 1:31 PM MST, 2 hours 39 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 231 PM MDT Sat Jun 6 2020 .Meso Update... Issued at 1106 AM MDT Sat Jun 6 2020 Latest radar loop from KGJX was showing a strong line of convection occurring just southwest of Grand Junction. Latest satellite loop was showing a nice pocket of instability ahead of that line of strong convection with around 60 degree dewpoints in Grand Junction yielding to instability around 1000j/kg. In addition, there is strong subsidence building behind that line which is most likely resulting in 70+ mph wind gusts. That is quite impressive for this region of the country where widespread severe storms are a rarity. Before this cluster of convection moves our direction we may see some intensification of this area of showers in northern Colorado. The HREF is showing some indication of this occurring during the next hour or so. This may yield to some wind gusts up to 60 mph with these showers and isolated thunderstorms at the leading edge of the 50 to 70kt 500mb jet streak. However, our main concern appears to be with this secondary line of convection currently moving through Grand Junction. The latest HRRR has this secondary line moving into the southwest portion of our area by 21z and pushes quickly northeast into the Nebraska panhandle by 00Z. The main threat with this line of storms will be 70+ mph winds with some pockets of hail. If some of these storms do produce some larger hail then it may create more damage especially if it is wind driven. A tornado cannot be ruled with good 0-1km storm relativity helicity 100-200m^2/s^2 along the leading edge of this line, but it will most likely be very brief. This line of convection should move out of the area by 03Z. Stay tuned to weather updates this afternoon. These storm motions will be very quick at speeds of 50 to 70 mph, and things will evolve quickly. When a warning is issued be sure to take appropriate shelter. .SHORT TERM...(Today & Tonight) Issued at 400 AM MDT Sat Jun 6 2020 A complicated forecast scenario across southeast Wyo & the western Neb Panhandle over the next 12-24 hours. Main weather concerns are dealing with the potential for widespread severe thunderstorms, as well as strong (non-convective) winds across portions of the high- plains. The latest GOES 16/17 Water Vapor satellite loop indicates a vigorous mid & upper-level short wave currently moving ashore in southern CA. Abundant moisture was seen streaming northward across the 4 Corners & central Rockies, contributing to widespread shower activity across western CO & WY. A few wind gusts of 60-70 MPH are already being observed with some of these showers. The aforementioned short wave is expected to continue to intensify & lift rapidly northeastward over the next few hours with the main trough axis reaching the WY/CO border by 18-21z. Prior to that, we should see a gradual uptick in clouds as well as showers/storms as leading H5 vort energy overspreads the region early this AM. There continue to be concerns with the potential for early morning cloud cover and precipitation to contaminate the warm sector and perhaps limit potential instability. Even so, high-resolution models still suggest a narrow window of opportunity for higher CAPE values near 2500 J/kg over mainly the western Nebraska Panhandle between 18z & 21z today with dew points in the lower 60s. It appears likely that more robust convection will begin increasing in coverage along the Laramie Range by 18z with significant dynamic forcing, with storms rapidly spreading north & east as capping erodes. Southerly 500 mb flow of 50+ knots will support quick storm motions along with good chances for severe wind gusts. Deep & intense, unidirectional flow aloft will provide effective vertical shear values up to 70 knots, more than sufficient for organized storms w/ a mainly linear storm mode given straight low-level hodographs. The orientation of low & mid-level winds will also support substantial rear inflow and cold pool development with multiple bowing line segments. Soundings are showing up to 70 knots available within the lowest 5k-10k feet, so significant (75+ MPH) thunderstorm wind gusts are possible through the afternoon. This threat may come in multiple waves as mid-level short wave energy pivots across the CWA through about 00z. SPC ENH Risk for the northern NE Panhandle & SLGT for the remainder of the CWA look reasonable, albeit still conditional based on instability fields. The threat for hail and/or tornadoes is less certain. Hail may not become particularly large today given the linear storm mode, but a small chance may exist for a couple of discrete supercells to take shape ahead of the main storm complex. If these discrete storms do develop while sufficient instability still exists (models continue to show this decreasing rapidly through the afternoon), hail to 2" in diameter would be possible given the available shear supporting intense, rotating updrafts. Hail sizes may otherwise by limited by competing updrafts w/ winds becoming a dominant threat w/ westward extent as instability wanes. The tornado threat today is low given limited hodograph curvature, but a non-zero threat does exist over the Nebraska Panhandle with any discrete storms as soundings still show some modest veering in the lowest kilometer w/ fairly intense speed shear leading to strong 0-1 km SRH near the surface low. The surface low should move into southwestern SD by 0z this evening w/ west to southwesterly surface winds developing in its wake, likely contributing to decreasing convective activity toward evening. In addition to the convective wind gust threat, a period of strong winds may develop over the southern Nebraska Panhandle by early to mid afternoon. An increasing surface pressure gradient, coupled w/ 700-800 mb flow in excess of 55 knots and cooling thermal profiles enhancing low-level mixing, could support high wind gusts where t- storms are not present. There were two reasons for not issuing the High Wind Warning with this package. 1) Clouds may yield lower LRs than forecast soundings indicate, and 2) We fully anticipate winds to be near severe criteria with afternoon convection, which should be a higher overall hazard to life and property than general winds today. The day shift will need to monitor this as well. .LONG TERM...(Sunday - Friday) Issued at 400 AM MDT Sat Jun 6 2020 Deep upper-level troughing over the northwestern CONUS will likely continue to promote shower & thunderstorm chances through at least Monday w/ a significant cold frontal passage on Monday expected to plunge 700 mb temperatures into the single digits to around 0 C by 00z Tue. Lows Tuesday morning may be at or near freezing for areas along/west of I-25 w/ even some light snow possible. Yes, you just read that correctly for June 8th-9th. Starting to trend warmer and drier mid/late week with a return to upper-level ridging. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Thunderstorms developing late this morning across western CO will be the main aviation hazard heading into this afternoon as these storms make their way towards area terminals. Wind gusts exceeding 50 kts are a high possibility with these storms while elevated winds will continue throughout the day and early evening. Storms will approach KRWL as soon as 19z while eventually making their way into the Nebraska Panhandle around 21-22z. VFR conditions are expected with these storms as higher cloud bases expected, however temporary drops in visibility will be possible in the heaviest TSTM activity. && .FIRE WEATHER... Issued at 228 PM MDT Sat Jun 6 2020 Dry and windy conditions are expected on Sunday especially east of the Laramie Range with gusts of 20 to 30 mph from the south- southwest. Mixing heights will range from 10 to 12kft. Some scattered afternoon showers and thunderstorms will also be possible west of Laramie on Sunday afternoon. Cooler conditions will take place on Monday and Tuesday as an upper level trof moves through the area. This trof will bring some scattered rain showers with even snow showers above 7000ft Monday night into Tuesday morning. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && SHORT TERM...CLH LONG TERM...CLH AVIATION...MB FIRE WEATHER...REC
Hazardous Weather Outlook National Weather Service Cheyenne WY 624 AM MDT Sat Jun 6 2020 NEZ002-003-019>021-054-055-095-096-WYZ101>119-071230- Dawes-Box Butte-Scotts Bluff County-Banner County-Morrill- Kimball County-Cheyenne-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- 624 AM MDT Sat Jun 6 2020 This hazardous weather outlook is for portions of panhandle Nebraska...western Nebraska...east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Numerous thunderstorms are expected across a large portion of the area this afternoon. The most likely time frame for severe thunderstorms will be between Noon and 6 PM today. Wind gusts to 70 MPH will be the primary hazard, although isolated hail up to golf ball size is also possible especially over western Nebraska. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY Daily chances for showers and thunderstorms will persist through at least Monday afternoon. Chances for severe weather appear low at this time. A strong cold front will force overnight lows into the mid 30s for areas along and west of Interstate 25 on Monday night. Freezing temperatures are possible. .Spotter information statement... Spotter activation may be necessary this afternoon.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
442 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 PM TSTM WND GST 8 S SIBLEY PEAK 42.32N 105.05W
06/06/2020 M79 MPH PLATTE WY MESONET
COLEMAN MESONET SITE ALONG I25-US26-US87
WIND GUST OF 79MPH.
&&
BMWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
457 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0452 PM TSTM WND GST GUN BARREL 41.44N 104.34W
06/06/2020 M68 MPH LARAMIE WY MESONET
MESONET STATION KGUN GUN BARREL (WYDOT).
&&
AWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
459 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0455 PM TSTM WND GST 4 WSW PINE BLUFFS 41.15N 104.13W
06/06/2020 M67 MPH LARAMIE WY AWOS
AWOS STATION K82V PINE BLUFFS AIRPORT - 82V.
&&
AWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
501 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0425 PM TSTM WND GST 8 ENE CHEYENNE 41.18N 104.64W
06/06/2020 M60 MPH LARAMIE WY MESONET
MESONET STATION UP166 8.4 E NORTH CHEYENNE
(UPR).
&&
AWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
505 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0452 PM TSTM WND GST ESTERBROOK 42.42N 105.36W
06/06/2020 M65 MPH CONVERSE WY MESONET
MESONET STATION ESTW4 23 S DOUGLAS -
ESTERBROOK RAWS - EBK.
&&
AWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
508 PM MDT SAT JUN 6 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0508 PM TSTM WND GST 1 ESE GUERNSEY 42.26N 104.73W
06/06/2020 E56 MPH PLATTE WY PUBLIC
CAMP GUERNSEY.
&&
AWThe Cheyenne radar (KCYS), 79 km away, was scanning. The volume nearest the first event began at 23:10 UTC.
31 thunderstorm wind. Local standard time, as filed.
AWOS station K1BW - Bravo Madis reported wind gust 14 miles west of Harrisburg, NE.
AWOS station KIBM - Kimball Municipal Airport reported wind gust.
ASOS station KBFF - Scottsbluff Airport reported wind gust.
Report from mPING of 1 inch tree limbs broken and shingles blown off.
ASOS station KBFF - Scottsbluff Airport reported wind gust along with 46 MPH sustained winds.
Reports of windows broken out of home.
Reported wind gust from a Davis System.
Davis System measured wind gust.
Pivot damage from wind gusts reported south of Melbeta.
Mesonet station K1GW - Golf (Sidney) reported wind gust 4 miles north-northwest of Brownson, NE.
ASOS station KBFF - Scottsbluff Airport reported wind gust.
Nebraska Public Power District reports 3,361 customers without power in the Scottsbluff area due to wind.
Railroad cross beam broken at Ave B in Scottsbluff.
ASOS station KSNY - Sidney Municipal Airport reported gust with 33 MPH sustained winds.
Report of a roof blown off a building.
Reports of power poles broken along a 3 to 4 mile stretch of road 1 mile west of McGrew.
Power outages due to wind gusts reported in Bayard and surrounding rural areas.
Several small outbuildings blown over, metal roofs stripped off, large trees blown over, and pivots flipped over in the Melbeta area.
Tree blew over and came through the roof of a house in Scottsbluff, NE. No injuries reported.
Reports of tin being blown off a shed and rolling across US 26 striking two motorcyclists. Highway was shutdown and 2 injuries were reported.
Davis station measured wind gust.
Multiple 3 to 4 inch diameter trees uprooted in town.
ASOS station KAIA - Alliance Municipal Airport reported wind gust.
RAWS station AGTN1 - Agate Fossil Beds reported wind gust 2 mile east-northeast of Agate, NE.
RAWS station MTRN1 - Montrose reported wind gust 17 miles north-northeast of Harrison, NE.
Multiple trees uprooted at Bridgeport Cemetery.
ASOS station KCDR - Chardron Municipal Airport reported wind gust.
ASOS station KSNY - Sidney Municipal Airport reported wind gust in stratiform region of squall line.
Minor structure blow overs at intersection of county road 8 and 19 due to estimated wind gusts around 60 MPH.
RAWS station HRSN1 - Kings Canyon reported wind gust in Chadron State Park.
Union Pacific Railroad mesonet station UP252 - SUNOL1 reported wind gust 8 miles west of Lodgepole, NE.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2020Every state in 2020This day in weather historyWarnings in Nebraska, June 2020
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: 892582, 892583, 892584, 892585, 892586, 892587, 892588, 892594, 892596, 892595, 892597, 892598, 892599, 892600, 892601, 892602, 892603, 892604, 892605, 892589, 894230, 894231, 894232, 894233, 894234, 894235, 894236, 894237, 894238, 894239, 894240.