In the early afternoon hours on the 21st, a boundary began firing severe thunderstorms over Southwest Nebraska and Northwest Kansas. These storms generally moved to the north-northeast as the boundary moved east.
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.
In the early afternoon hours on the 21st, a boundary began firing severe thunderstorms over Southwest Nebraska and Northwest Kansas. These storms generally moved to the north-northeast as the boundary moved east. In Nebraska, these storms produced wind gusts in excess of 80 mph, 2.5 inch diameter hail, 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 Sep 21, 2:21 PM CST, 34 minutes earlier.
Area Forecast Discussion National Weather Service Goodland KS 221 PM MDT Thu Sep 21 2023 .SHORT TERM...(This evening through Friday night) Issued at 122 PM MDT Thu Sep 21 2023 Synoptic Overview: Cyclonic flow aloft will prevail over the Intermountain West and central Rockies in this period, as an upper level low.. situated over southeastern Oregon at 12Z this morning.. meanders in place (today), then progresses eastward across southern Idaho (Fri) and Wyoming (Fri night). Today-Tonight: Diffluent flow aloft in the lee of the Rockies will persist through tonight.. anchoring a broad lee cyclone over eastern CO and extreme western KS. Primary forecast concern in this period revolves around convective development/coverage this afternoon and evening. Latest observational and mesoanalysis data suggest that forcing this aft/eve will primarily be confined to the lower-levels.. e.g. convergence invof a dryline extending (roughly) from Imperial, NE to Oberlin and Quinter, KS at 19Z. Considerable model-to-model and run-to-run variability persists with regard to simulated reflectivity forecasts via convection allowing guidance this aft/eve.. as one would expect in a pattern characterized by weak synoptic forcing. Recent satellite, radar and mesoanalysis trends suggest that convective development is (relatively) more likely to occur along northern portions of the dryline (invof McCook, Oberlin, Norton).. where moisture pooling (850mb dewpoint maxima ~14-16C) will assist in the erosion of lingering convective inhibition around and shortly after peak heating (~22-23Z). Along and east of the dryline, where rich low- level moisture (850mb dewpoints 12-16C) and steep (8-8.5 C/km) mid-level lapse rates are yielding strong instability (2000-3000 J/kg MLCAPE) -- amidst a kinematic environment characterized by backed low-level flow and 35-40 knots of effective deep layer shear -- expect a potential for robust supercells capable of producing all hazards, mainly in the 22-03Z time frame. Fri-Fri night: Rich low-level moisture is progged to shift east and north of the Tri-State area in this period.. as the aforementioned lee cyclone shifts eastward from CO into western KS. At this time, all available guidance suggests that dry conditions will prevail. .LONG TERM...(Saturday through Thursday) Issued at 119 PM MDT Thu Sep 21 2023 This part of the forecast will be relatively tranquil. The upper level flow may be from the northwest or southwest, depending on where the ridge axis of the strengthening upper level high pressure will be. As the ridge continues to intensify mid next week, there is a potential a weak short wave trough may form over the forecast area around the periphery of the ridge. Looking at the GEFS and ECMWF members, there is a very low probability for rainfall to occur and most of that probability is east of the forecast area. Have low confidence these chances for rainfall will materialize given the strengthening ridge. Otherwise the end of next week could be breezy given the breezy low level winds over the Central Plains. Regarding fire weather potential, Saturday continues to looking interesting. As the relative humidity falls through the afternoon, so does the northwest wind. In similar past patterns, this has not proven to be a critical fire weather day due to the winds not lasting long enough before becoming lighter. Temperatures will gradually warm to seasonal values after the cold front moves through early Saturday. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1200 PM MDT Thu Sep 21 2023 GLD: VFR conditions are anticipated to prevail through the TAF period. 10-20 knot S-SSW winds will prevail this afternoon, backing to the SSE-SE after sunset this evening. Winds will become variable AOA sunrise Friday morning.. as a weak lee cyclone progresses eastward from eastern CO into far western KS. MCK: VFR conditions will prevail this afternoon. Adverse aviation conditions associated with thunderstorms are possible late this aft/eve.. mainly in the 22-03Z time frame. Sub-VFR conditions associated with low ceilings /stratus/ are anticipated to develop this evening and overnight.. persisting through sunrise Friday morning. VFR conditions will return near the end of the TAF period, ~15-16Z Friday morning. 15-25 knot SE winds will prevail this afternoon.. backing to the E-ESE this evening and decreasing to 10-15 knots overnight. Gusty/erratic winds can be expected invof any thunderstorms. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && SHORT TERM...Vincent LONG TERM...JTL AVIATION...Vincent
Hazardous Weather Outlook National Weather Service Goodland KS 156 PM MDT Thu Sep 21 2023 COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-222000- Yuma-Kit Carson-Cheyenne-Rawlins-Decatur-Norton-Sherman-Thomas- Sheridan-Graham-Wallace-Logan-Gove-Greeley-Wichita-Dundy-Hitchcock- Red Willow- 156 PM MDT Thu Sep 21 2023 /256 PM CDT Thu Sep 21 2023/ This hazardous weather outlook is for extreme southwest Nebraska... northwest Kansas and east central Colorado. .DAY ONE...THIS AFTERNOON AND TONIGHT... A Tornado Watch is in effect for portions northwest Kansas and southwest Nebraska until 9 PM MDT, 10 PM CDT this evening. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH THURSDAY... Near critical to critical fire weather conditions are anticipated in far eastern Colorado and far western Kansas Friday afternoon, mainly along and west of a line from St. Francis to Tribune. Caution should be used if burning outdoors. Elevated to critical fire weather conditions are possible along and west of Kansas Highway 25 Saturday afternoon. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report any severe or significant weather to the National Weather Service in Goodland via social media or telephone. We appreciate your reports, thank you! Vincent
Special Weather Statement
National Weather Service Goodland KS
308 PM CDT Thu Sep 21 2023
NEZ080-212045-
Hitchcock NE-
308 PM CDT Thu Sep 21 2023
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL HITCHCOCK COUNTY THROUGH
345 PM CDT...
At 307 PM CDT, Doppler radar was tracking a strong thunderstorm near
Trenton. This thunderstorm was nearly stationary.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This storm will remain over mainly rural areas of central Hitchcock
County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until 1000 PM CDT for southwestern
Nebraska.
&&
LAT...LON 4022 10076 4009 10098 4020 10116 4035 10106
4035 10097
TIME...MOT...LOC 2007Z 219DEG 4KT 4020 10102
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
024The Goodland radar (KGLD), 119 km away, was scanning. The volume nearest the first event began at 20:54 UTC.
13 hail, 2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Spotter driving a semi on Highway 6 ran into storm and had hail ranging from ping pong to tennis ball.
Trained spotter reported 1.75 inch diameter hail in Culbertson.
Public report of 1.5 inch diameter hail becoming heavy rain.
Trained spotter reported 1.5 inch diameter hail east of Culbertson.
Mesonet station 9.5 miles SW of McCook, E9525.
Report received of hail up to 2 inches in diameter.
Hail on the ground following the storm ranged from nickel to half dollar sized.
McCook Dispatch reported several streets flooded along with Barnet Park and basements in several homes in the McCook area.
Pea to nickel sized hail east of McCook.
Trained spotter reported 1 inch diameter hail.
Report via social media of constant hail pea to quarter size between 7 to 735 pm CDT with first round of storms through Danbury.
Gust recorded 8ssw of Indianola, NE on a Nebraska state mesonet site.
Trained spotter reported golf ball sized hail in Danbury.
Sherriff reported 1.75 inch diameter hail.
Red Willow County law enforcement relayed a report of windows broken by wind-driven hail in Danbury.
Report via social media with photo of estimated golf ball size hail in Danbury with second round of storms.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2023Every state in 2023This day in weather historyWarnings in Nebraska, September 2023
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: 1140150, 1140151, 1140152, 1140153, 1140163, 1140155, 1140154, 1140165, 1140156, 1140157, 1140158, 1140164, 1140159, 1140160, 1140161, 1140162.