Alert archive / Kansas / Tornado Watches in 2021
Tornado Watch 154
The Storm Prediction Center issued this tornado watch at May 8, 2021, 6:30 PM CDT for 18 counties in Kansas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 8, 2021, 6:30 PM CDT (23:30 UTC)
- Expired
- May 9, 2021, 1:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 65 kt
Counties Clay County, KS, Cloud County, KS, Dickinson County, KS, Douglas County, KS, Franklin County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Lyon County, KS, Morris County, KS, Osage County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Shawnee County, KS, Wabaunsee County, KS, Washington County, KS
The radar
The Topeka radar (KTWX), 59 km from the middle of the area, began a volume at 23:32 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 60%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 7:27 PM CDT | Severe Thunderstorm Warning | TOP | Republic | 33 min |
| May 8, 7:56 PM CDT | Severe Thunderstorm Warning | TOP | Republic, Washington | 49 min |
| May 8, 8:38 PM CDT | Severe Thunderstorm Warning | TOP | Marshall, Washington | 52 min |
| May 8, 8:48 PM CDT | Severe Thunderstorm Warning | TOP | Dickinson | 57 min |
| May 8, 9:24 PM CDT | Severe Thunderstorm Warning | TOP | Geary, Morris, Riley | 51 min |
| May 8, 9:51 PM CDT | Severe Thunderstorm Warning | TOP | Geary, Pottawatomie, Riley | 24 min |
| May 8, 10:03 PM CDT | Severe Thunderstorm Warning | TOP | Geary, Jackson, Morris, Pottawatomie, Riley, Shawnee and 1 more | 42 min |
| May 8, 10:11 PM CDT | Tornado Warning | TOP | Pottawatomie, Riley, Wabaunsee | 21 min |
| May 8, 10:43 PM CDT | Severe Thunderstorm Warning | TOP | Lyon, Osage, Shawnee, Wabaunsee | 47 min |
| May 8, 11:00 PM CDT | Severe Thunderstorm Warning | TOP | Jackson, Jefferson, Shawnee | 45 min |
| May 8, 11:00 PM CDT | Severe Thunderstorm Warning | TOP | Dickinson | 45 min |
| May 9, 12:15 AM CDT | Flash Flood Warning | TOP | Shawnee, Wabaunsee | 4 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Topeka, KS (KTOP), launched 12:00Z, 11.5 hours before the alert went out and 102 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
- 1087 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 179 m²/s²
- 0-3 km storm-relative helicity
- 242 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
884
WWUS20 KWNS 082328
SEL4
SPC WW 082328
KSZ000-090600-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 154
NWS Storm Prediction Center Norman OK
630 PM CDT Sat May 8 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Northeast Kansas
* Effective this Saturday night and Sunday morning from 630 PM
until 100 AM CDT.
* Primary threats include...
A couple tornadoes possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter likely
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
SUMMARY...Intense thunderstorms are expected to develop this evening
along a warm front over northeast Kansas and track across the watch
area. Very large hail and isolated tornadoes are the possible early
this evening, with an increasing risk of damaging winds with the
storms after dark.
The tornado watch area is approximately along and 35 statute miles
north and south of a line from 15 miles southwest of Concordia KS to
30 miles east of Topeka KS. For a complete depiction of the watch
see the associated watch outline update (WOUS64 KWNS WOU4).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 153...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 27035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 3:24 PM CDT | Mesoscale Discussion | SPC | Barton, Ellis, Ellsworth, Jewell, Lincoln, Mitchell and 7 more | 2 hr |
| May 8, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Ellis, Ellsworth, Hodgeman, Jewell, Lincoln and 11 more | 6 hr |
| May 8, 6:06 PM CDT | Mesoscale Discussion | SPC | Atchison, Barton, Brown, Clay, Cloud, Dickinson and 29 more | 114 min |
| May 8, 6:42 PM CDT | Severe Thunderstorm Watch | SPC | Atchison, Brown, Doniphan, Marshall, Nemaha | 6 hr |
Nearby
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.