Alert archive / Missouri / Tornado Watches in 2021
Tornado Watch 117
The Storm Prediction Center issued this tornado watch at Apr 28, 2021, 9:33 AM CDT for 10 counties in Missouri. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2021, 9:33 AM CDT (14:33 UTC)
- Expired
- Apr 28, 2021, 1:08 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Christian County, MO, Douglas County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO
The radar
The Springfield radar (KSGF), 83 km from the middle of the area, began a volume at 14:32 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 9:33 AM CDT | Flash Flood Warning | SGF | Christian, Taney | 6 hr |
| Apr 28, 9:37 AM CDT | Severe Thunderstorm Warning | SGF | Christian, Douglas, Ozark, Taney | 68 min |
| Apr 28, 9:43 AM CDT | Tornado Warning | SGF | Christian, Taney | 32 min |
| Apr 28, 10:14 AM CDT | Tornado Warning | SGF | Christian, Douglas, Webster | 31 min |
| Apr 28, 10:15 AM CDT | Flash Flood Warning | SGF | Douglas, Ozark, Taney, Webster, Wright | 6 hr |
| Apr 28, 10:21 AM CDT | Severe Thunderstorm Warning | SGF | Douglas, Howell, Ozark, Taney, Webster, Wright | 39 min |
| Apr 28, 10:24 AM CDT | Tornado Warning | SGF | Ozark | 36 min |
| Apr 28, 10:44 AM CDT | Flash Flood Warning | SGF | Douglas, Ozark | 6 hr |
| Apr 28, 10:58 AM CDT | Tornado Warning | SGF | Douglas, Ozark | 32 min |
| Apr 28, 11:12 AM CDT | Flash Flood Warning | SGF | Howell, Texas | 6 hr |
| Apr 28, 11:27 AM CDT | Severe Thunderstorm Warning | SGF | Wright | 33 min |
| Apr 28, 11:29 AM CDT | Severe Thunderstorm Warning | SGF | Douglas, Howell | 22 min |
| Apr 28, 11:49 AM CDT | Severe Thunderstorm Warning | SGF | Howell, Oregon, Shannon | 41 min |
| Apr 28, 12:01 PM CDT | Flash Flood Warning | SGF | Dent, Laclede, Phelps, Pulaski, Texas, Wright | 6 hr |
| Apr 28, 12:02 PM CDT | Tornado Warning | SGF | Howell, Oregon, Shannon | 28 min |
| Apr 28, 12:07 PM CDT | Flash Flood Warning | SGF | Oregon, Shannon | 6 hr |
| Apr 28, 12:30 PM CDT | Severe Thunderstorm Warning | SGF | Oregon, Shannon | 30 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 2.6 hours before the alert went out and 115 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
- 34 J/kg
- Mixed-layer CIN
- -105 J/kg
- Mixed-layer LCL
- 1441 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
573 WWUS20 KWNS 281424 SEL7 SPC WW 281424 MOZ000-282000- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 117 NWS Storm Prediction Center Norman OK 925 AM CDT Wed Apr 28 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Missouri * Effective this Wednesday morning and afternoon from 925 AM until 300 PM CDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A cluster of intense thunderstorms may persist through the early afternoon, affecting the watch area. Locally damaging wind gusts and isolated tornadoes are possible. The tornado watch area is approximately along and 35 statute miles north and south of a line from 25 miles south of Springfield MO to 40 miles east northeast of West Plains MO. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 116... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Hart
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 8:52 AM CDT | Mesoscale Discussion | SPC | Butler, Dunklin, Howell, Oregon, Ozark, Ripley and 1 more | 113 min |
| Apr 28, 10:56 AM CDT | Mesoscale Discussion | SPC | Douglas, Howell, Oregon, Ozark, Shannon, Texas and 1 more | 64 min |
| Apr 28, 12:33 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Carter, Madison, Mississippi and 7 more | 57 min |
| Apr 28, 12:40 PM CDT | Severe Thunderstorm Watch | SPC | Bollinger, Butler, Cape Girardeau, Carter, Mississippi, New Madrid and 4 more | 7 hr |
| Apr 28, 3:29 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Mississippi, New Madrid, Scott and 1 more | 91 min |
| Apr 28, 5:25 PM CDT | Mesoscale Discussion | SPC | Mississippi | 2 hr |
Nearby
Tornado Watches in Missouri, 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.