A linear cluster of storms moved east into northwest Kansas from Yuma County and merged into one large line with clusters in Cheyenne County, Colorado and southwest Nebraska. These storms produced up to 60 mph thunderstorm wind gusts and various sized hail up to two inches in diameter.
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.
A linear cluster of storms moved east into northwest Kansas from Yuma County and merged into one large line with clusters in Cheyenne County, Colorado and southwest Nebraska. These storms produced up to 60 mph thunderstorm wind gusts and various sized hail up to two inches in diameter.
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 Aug 11, 3:29 PM MST, 51 minutes earlier.
Area Forecast Discussion National Weather Service Goodland KS 429 PM MDT Tue Aug 11 2020 .SHORT TERM...(This evening through Thursday night) Issued at 150 PM MDT Tue Aug 11 2020 Across the Tri State region this afternoon, much of the area is under sunny skies with the exception being along and just east of the Colorado border. Cloud cover here just out ahead of an inverted surface trough currently over eastern Colorado. Temperatures as of 100 pm MDT have a range from the upper 80s through the 90s, with winds SSE gusting to 20-30 mph at times. For this afternoon and evening, it will be the inverted trough west of the CWA for the focus of rw/trw initiation. Area radar is showing some convection already forming along the trough west of the CWA. Models do trend an area/line of convection east thru the area this evening before moving east of the CWA. Convection is aided by an upper level shortwave moving over the upper ridge that has been in place for the past several days. SPC has continued a Marginal Risk for severe thunderstorm potential for areas along and west of Highway 25 thru the evening hrs. Hail(1-2 inches), winds (60-70 mph) and potential for locally heavy rainfall are the expected hazards. The wind and hail threat will morph into more of a wind threat later tonight as activity traverses the CWA. For Wednesday and Thursday, upper ridge to remain in place over the central portion of the country, providing west to northwest upper flow. A couple more shortwaves are expected to traverse the upper ridge over these two days, and combined with a surface trough/front moving off the Front Range, eastern portions of the region could see strong to severe storm potential. Best chances from latest models has a Marginal/Slight risk area for Wednesday and a new Marginal Risk area for Thursday. Both days outlooks will focus on locales along and east of approx Highway 25. This works up to the proximity of the surface front that sets up over the CO/KS/NE border. Current guidance for Thursday has no chances mentioned for the afternoon/evening hrs for storms, but with a Marginal area east, have opted to mention a slight chance for locales mainly Highway 83 and east. Same threats as today are possible for storms on Wed/Thu. For temps, hot and above normal numbers are expected for daytime highs across the entire CWA, with mid 90s on Wednesday transitioning to mid and upper 90s for Thursday. Overnight lows will range in the 60s thru the short term period, with warmest locales in the eastern half of the CWA. .LONG TERM...(Friday through Tuesday) Issued at 1220 PM MDT Tue Aug 11 2020 The upper level pattern starts with high pressure over New Mexico and Arizona with low pressure in Canada with troughiness extending south into the northern plains. The upper high slowly retrogrades northwest into Nevada and Utah by 12z Monday continuing through Tuesday amplifying the ridge axis north into the northern plains. The above mentioned upper low and trough slide east toward the Great Lakes. There appears to be enough moisture in the 850-500mb layer for a few thunderstorms Saturday afternoon and evening then again Sunday through Tuesday. High temperatures Friday in the mid to upper 90s cooling a bit Saturday to the low to mid 90s. Further cooling is expected Sunday through Tuesday with below normal readings in the low to mid 80s. Low temperatures Friday night and Saturday night in the upper 50s to mid 60s cooling into the mid 50s to around 60 Sunday night and Monday night. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 430 PM MDT Tue Aug 11 2020 GLD: Adverse aviation conditions assoc/w thunderstorms are expected late this afternoon and early this evening, mainly between 23-02Z. Otherwise, VFR conditions are anticipated to prevail through the TAF period. SE winds at 15-25 knots will weaken to 8-13 knots this evening and persist overnight. SE winds will increase to 12-17 knots by late Wed morning or early Wed afternoon. MCK: Adverse aviation conditions assoc/w thunderstorms are possible late this afternoon and early this evening, mainly between 00-04Z. Otherwise, VFR conditions are anticipated to prevail through the TAF period. SE winds at 15-25 knots will weaken to 8-13 knots this evening, perhaps becoming variable at times overnight. S-SE winds will increase to 12-17 knots by late Wed morning or early Wed afternoon. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && SHORT TERM...JN LONG TERM...99 AVIATION...VINCENT
Hazardous Weather Outlook National Weather Service Goodland KS 903 AM MDT Tue Aug 11 2020 COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-121515- Yuma County-Kit Carson County-Cheyenne County-Cheyenne-Rawlins- Decatur-Norton-Sherman-Thomas-Sheridan-Graham-Wallace-Logan-Gove- Greeley-Wichita-Dundy-Hitchcock-Red Willow- 903 AM MDT Tue Aug 11 2020 /1003 AM CDT Tue Aug 11 2020/ This hazardous weather outlook is for extreme southwest Nebraska... northwest Kansas and east central Colorado. .DAY ONE...TODAY AND TONIGHT... This afternoon and evening, isolated strong to severe thunderstorms will be possible. Storms are expected to develop in Eastern Colorado before progressing eastward later in the afternoon and evening. Any storms that develop will be capable of producing damaging wind gusts, hail, and locally heavy rainfall. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY... No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed today. Please send any reports of fog, severe weather or rainfall totals to the National Weather Service via phone or social media.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GOODLAND KS
353 PM MDT TUE AUG 11 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0353 PM TSTM WND GST 1 NNW WRAY 40.10N 102.24W
08/11/2020 M54 MPH YUMA CO AWOS
&&
JNSpecial Weather Statement National Weather Service Goodland KS 440 PM MDT Tue Aug 11 2020 COZ092-112330- Cheyenne County CO- 440 PM MDT Tue Aug 11 2020 ...SIGNIFICANT WEATHER ADVISORY FOR EASTERN CHEYENNE COUNTY IN EAST CENTRAL COLORADO UNTIL 530 PM MDT... At 440 PM MDT, Doppler radar was tracking a strong thunderstorm 9 miles west of Cheyenne Wells, moving northeast at 15 mph. Wind gusts up to 55 mph are possible with this storm. Locations impacted include... Cheyenne Wells, Firstview and Arapahoe. This includes Highway 385 between mile markers 136 and 169. 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. && LAT...LON 3861 10269 3904 10270 3905 10205 3862 10205 TIME...MOT...LOC 2240Z 247DEG 11KT 3882 10253 Vincent
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GOODLAND KS
447 PM MDT TUE AUG 11 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0840 AM NON-TSTM WND GST 4 S CARUSO 39.28N 101.82W
08/10/2020 M62 MPH SHERMAN KS MESONET
KANSAS MESONET SITE RECORDED A WIND GUST OF
62 MPH. TEMPERATURE ROSE TO 82 DEGREES FROM
72 DEGREES FIVE MINUTES PRIOR.
1052 AM NON-TSTM WND GST 10 WSW MINGO 39.21N 101.13W
08/10/2020 M58 MPH THOMAS KS MESONET
CORRECTS PREVIOUS NON-TSTM WND GST REPORT
FROM 10 WSW MINGO. MINI HEAT BURST CAUSED A
58 MPH WIND GUST WITH A TEMPERATURE OF 91
DEGREES.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GOODLAND KS
511 PM MDT TUE AUG 11 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0455 PM HIGH SUST WINDS SAINT FRANCIS 39.77N 101.80W
08/11/2020 M40 MPH CHEYENNE KS AWOS
AWOS STATION KSYF ST. FRANCIS CITY.
&&
MRCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GOODLAND KS
512 PM MDT TUE AUG 11 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM TSTM WND GST SAINT FRANCIS 39.77N 101.80W
08/11/2020 M57 MPH CHEYENNE KS MESONET
&&
MRCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GOODLAND KS
520 PM MDT TUE AUG 11 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM HAIL 9 N CHEYENNE WELLS 38.95N 102.35W
08/11/2020 E0.25 INCH CHEYENNE CO PUBLIC
TIME ESTIMATED BY RADAR.
&&
KMKThe Goodland radar (KGLD), 17 km away, was scanning. The volume nearest the first event began at 23:21 UTC.
5 hail, 2 thunderstorm wind. Local standard time, as filed.
An off-duty NWS Employee observed an estimated 50-60 mph wind gust associated with an outflow boundary moving southeast ahead of a linear cluster of storms.
Pea to penny sized hail fell for a duration of four minutes.
Several reports of various sized hail from nickel to hen egg in size that fell for a duration of approximately seven minutes in downtown Sharon Springs.
Several reports received of various sized hail from dime to quarter in size in the town of Colby. The quarter sized hail was reported at the intersection of KS-25 and I-70.
A report was received over Facebook of a few tennis ball sized hailstones mixed with nickel sized falling in the town of Oakley.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2020Every state in 2020This day in weather historyWarnings in Kansas, August 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: 916223, 916226, 916214, 916218, 916221, 916220, 916222.