Alert archive / Kansas / Tornado Watches in 2021
Tornado Watch 487
The Storm Prediction Center issued this tornado watch at Sep 2, 2021, 5:27 PM CDT for 33 counties in Kansas; 29 counties in Nebraska. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 2, 2021, 5:27 PM CDT (22:27 UTC)
- Expired
- Sep 2, 2021, 10:16 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
All 62 counties
Barton County, KS, Clay County, KS, Cloud County, KS, Dickinson County, KS, Ellis County, KS, Ellsworth County, KS, Geary County, KS, Jackson County, KS, Jewell County, KS, Lane County, KS, Lincoln County, KS, Lyon County, KS, Marshall County, KS, Mitchell County, KS, Morris County, KS, Nemaha County, KS, Ness County, KS, Osage County, KS, Osborne County, KS, Ottawa County, KS, Phillips County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Rooks County, KS, Rush County, KS, Russell County, KS, Saline County, KS, Shawnee County, KS, Smith County, KS, Trego County, KS, Wabaunsee County, KS, Washington County, KS, Adams County, NE, Buffalo County, NE, Butler County, NE, Clay County, NE, Dawson County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Gage County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Howard County, NE, Jefferson County, NE, Kearney County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Phelps County, NE, Polk County, NE, Saline County, NE, Seward County, NE, Sherman County, NE, Thayer County, NE, Valley County, NE, Webster County, NE, York County, NE
The radar
The Grand Island radar (KUEX), 63 km from the middle of the area, began a volume at 22:29 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 5:52 PM CDT | Tornado Warning | GID | Kearney, Phelps | 23 min |
| Sep 2, 6:06 PM CDT | Severe Thunderstorm Warning | TOP | Dickinson, Geary, Morris | 24 min |
| Sep 2, 6:14 PM CDT | Severe Thunderstorm Warning | GID | Buffalo, Kearney, Phelps | 46 min |
| Sep 2, 6:20 PM CDT | Tornado Warning | GID | Harlan | 25 min |
| Sep 2, 6:30 PM CDT | Severe Thunderstorm Warning | TOP | Dickinson, Geary, Morris | 30 min |
| Sep 2, 7:18 PM CDT | Severe Thunderstorm Warning | TOP | Geary, Morris, Wabaunsee | 27 min |
| Sep 2, 7:44 PM CDT | Severe Thunderstorm Warning | TOP | Lyon, Morris, Wabaunsee | 31 min |
| Sep 2, 8:41 PM CDT | Severe Thunderstorm Warning | TOP | Lyon | 34 min |
| Sep 2, 9:11 PM CDT | Severe Thunderstorm Warning | TOP | Lyon | 34 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
- Mesoscale Discussion 1682 Severe potential...watch possible
- Mesoscale Discussion 1683 Severe potential...watch possible
- Mesoscale Discussion 1685 Severe potential...watch possible
- Mesoscale Discussion 1686 Tornado watch 487
- Mesoscale Discussion 1687 Tornado watch 487
- Mesoscale Discussion 1688 Tornado watch 487
- Mesoscale Discussion 1689 Tornado watch 487
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 10.5 hours before the alert went out and 162 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1125 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 209 m²/s²
- 0-3 km storm-relative helicity
- 259 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
545
WWUS20 KWNS 022225
SEL7
SPC WW 022225
KSZ000-NEZ000-030500-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 487
NWS Storm Prediction Center Norman OK
525 PM CDT Thu Sep 2 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
North-central and Northeast Kansas
South-central and Southeast Nebraska
* Effective this Thursday afternoon from 525 PM until Midnight
CDT.
* Primary threats include...
A couple tornadoes possible
Scattered damaging winds and isolated significant gusts to 75
mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Storms are expected to further develop and intensify
through early evening in multiple corridors, initially across
north-central toward northeast Kansas as well as south-central
Nebraska. A couple of tornadoes will be possible across the region
aside from damaging winds and possibly some hail.
The tornado watch area is approximately along and 90 statute miles
east and west of a line from 35 miles north of Grand Island NE to 20
miles south of Salina KS. For a complete depiction of the watch see
the associated watch outline update (WOUS64 KWNS WOU7).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.
&&
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 27025.
...GuyerSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 1:28 PM CDT | Mesoscale Discussion | SPC | Decatur, Graham, Norton, Phillips, Sheridan | 2 hr |
| Sep 2, 2:11 PM CDT | Mesoscale Discussion | SPC | Dickinson, Geary, Ottawa, Pottawatomie, Riley, Saline and 2 more | 2 hr |
| Sep 2, 4:23 PM CDT | Mesoscale Discussion | SPC | Barton, Clark, Clay, Cloud, Dickinson, Edwards and 16 more | 97 min |
| Sep 1, 9:20 PM CDT | Mesoscale Discussion | SPC | Box Butte, Cherry, Dawes, Garden, Morrill, Scotts Bluff and 2 more | 85 min |
| Sep 1, 11:36 PM CDT | Mesoscale Discussion | SPC | Arthur, Cherry, Garden, Grant, Hooker, Sheridan | 84 min |
Nearby
Tornado Watches in Kansas, 2021Tornado Watches in Nebraska, 2021Every tornado watch in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.