Storms formed in eastern Colorado organizing into a line as they neared the Kansas border with isolated storms forming to the south of Cheyenne County in Colorado. The line of storms produced thunderstorm wind gusts up to 65 mph and flash flooding.
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 GLD wrote it up.
Storms formed in eastern Colorado organizing into a line as they neared the Kansas border with isolated storms forming to the south of Cheyenne County in Colorado. The line of storms produced thunderstorm wind gusts up to 65 mph and flash flooding.
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 Goodland, KS wrote its last area forecast discussion before the first event at Jun 27, 12:19 PM MST, 4 hours 11 minutes earlier.
Area Forecast Discussion National Weather Service Goodland KS 119 PM MDT Sat Jun 27 2020 .SHORT TERM...(This evening through Sunday) Issued at 1231 PM MDT Sat Jun 27 2020 18 UTC Water Vapor Imagery and RAP analysis indicate broad westerly flow aloft over the area,with short wave trough approaching northeastern Colorado per satellite imagery. At the surface, seeing two areas of cumulus developing, one along trough axis from Wray to Limon and another along a convergent area between Burlington and St. Francis. Main forecast concern will center around severe thunderstorm potential late this afternoon tonight. Expect thunderstorms to develop along trough in eastern Colorado by 22 UTC, although secondary area of cumulus to the east of the Colorado state line makes me think there may be 2 areas of initial development, especially as this area is supported by persistent forced ascent due to WAA. Despite the possibility of an isolated cell or two in Kansas, still think forecast will play out similar to yesterday. Storms will form along trough axis, and with high bases and strong DCAPE will quickly form strong cold pool/gust front. With the orientation of 0-3km wind shear, seems like a favorable environment for MCS to develop and remain in balance with cold pool for several hours. With potential organization into a linear mode and strong DCAPE think wind gusts up to 70 mph primary threat, although if isolated storms develop further east ahead of the line hail may become more of a threat. Storms should move across the area fairly quickly with any MCS out of the area by 06 UTC. On Sunday very warm and dry conditions expected. Heating may be enough to overcome any capping and with weak dryline developing would not be out of the question to see an isolated storm. Signal right now looks fairly weak however and think continued dry forecast is in order. .LONG TERM...(Monday through Saturday) Issued at 119 PM MDT Sat Jun 27 2020 The extended starts with troughing over the western US, ridging over the Southeastern and GREAT Lakes regions, and troughing over the New England States. This upper level pattern will produce southwest flow aloft over the Tri-States area and aid in dry and hot (highs are expected to reach at or above 100) conditions through Tuesday afternoon. Add in relative humidity values of 10 to 15 percent will result in possible fire weather conditions. Tuesday afternoon, the models are showing a cold front moving through the region and producing a chance of thunderstorms during the afternoon and evening hours, mainly the the northwestern part of the Tri-State region. For the rest of the week, temperatures will be in the above normal range of the middle 90s and an upper-level ridge will build over the High Plains and influence the area. The However, disturbances traveling within the upper-level flow may result in afternoon thunderstorms each day. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1118 AM MDT Sat Jun 27 2020 Another cluster of thunderstorms is expected to develop after 22Z near the KS/CO border and move east through 05Z. Appears GLD more likely to see impacts as these high based storms move over terminals. Storms will be forming into a squall line, with winds gusting over 45 kts likely. After storms pass, expect VFR conditions to prevail. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && SHORT TERM...JRM LONG TERM...BW AVIATION...JRM
Hazardous Weather Outlook National Weather Service Goodland KS 1253 PM MDT Sat Jun 27 2020 COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-281900- Yuma County-Kit Carson County-Cheyenne County-Cheyenne-Rawlins- Decatur-Norton-Sherman-Thomas-Sheridan-Graham-Wallace-Logan-Gove- Greeley-Wichita-Dundy-Hitchcock-Red Willow- 1253 PM MDT Sat Jun 27 2020 /153 PM CDT Sat Jun 27 2020/ This hazardous weather outlook is for extreme southwest Nebraska... northwest Kansas and east central Colorado. .DAY ONE...THIS AFTERNOON AND TONIGHT... Thunderstorms are expected to develop across eastern Colorado after 2 PM MDT and move across the area in the evening hours. A few severe storms are expected, with wind gusts of 60-70 mph and blowing dust the primary threats. Large hail in excess of an inch in diameter is also possible, especially as storms first develop. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY... Elevated to near critical fire weather conditions are expected Sunday, Monday, and Tuesday afternoons across East Central Colorado into parts of Northwest Kansas. .SPOTTER INFORMATION STATEMENT... If severe weather is observed, please report it to the National Weather Service in Goodland.
Special Weather Statement National Weather Service Goodland KS 415 PM MDT Sat Jun 27 2020 NEZ079-272230- Dundy NE- 415 PM MDT Sat Jun 27 2020 ...SPECIAL WEATHER STATEMENT... At 415 PM MDT, Doppler radar was tracking a strong thunderstorm 7 miles north of Haigler, or 16 miles east of Wray, moving northeast at 25 mph. Half inch hail and winds in excess of 30 mph will be possible with this storm. This storm will remain over mainly rural areas of southwestern Dundy County. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 4006 10199 4013 10203 4026 10184 4010 10172 TIME...MOT...LOC 2215Z 242DEG 22KT 4013 10191 AW
Special Weather Statement National Weather Service Goodland KS 438 PM MDT Sat Jun 27 2020 NEZ079-272300- Dundy NE- 438 PM MDT Sat Jun 27 2020 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN DUNDY COUNTY UNTIL 500 PM MDT... At 437 PM MDT, Doppler radar was tracking a strong thunderstorm 7 miles north of Haigler, or 15 miles east of Wray, moving east at 15 mph. Penny size hail will be possible with this storm. This storm will remain over mainly rural areas of southwestern Dundy County. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 4009 10190 4016 10193 4025 10176 4007 10167 TIME...MOT...LOC 2237Z 256DEG 13KT 4012 10193 AW
The Goodland radar (KGLD), 63 km away, was scanning. The volume nearest the first event began at 23:28 UTC.
3 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Fourteen inches of water on County Road DD approximately half a mile south of Highway 36 due to heavy rain.
ASOS observed 58 mph gusts with 43 mph sustained.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2020Every state in 2020This day in weather historyWarnings in Colorado, 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: 898399, 898404, 898405, 898407.