Alert archive / Missouri / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 79
The Storm Prediction Center issued this severe thunderstorm watch at Apr 9, 2021, 3:13 PM CDT for 7 counties in Arkansas; 17 counties in Missouri. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2021, 3:13 PM CDT (20:13 UTC)
- Expired
- Apr 9, 2021, 10:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 24 counties
Baxter County, AR, Fulton County, AR, Izard County, AR, Lawrence County, AR, Marion County, AR, Randolph County, AR, Sharp County, AR, Barry County, MO, Christian County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO
The radar
The Springfield radar (KSGF), 29 km from the middle of the area, began a volume at 20:15 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
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 3:14 PM CDT | Severe Thunderstorm Warning | LZK | Baxter, Fulton, Izard, Marion | 31 min |
| Apr 9, 3:17 PM CDT | Severe Thunderstorm Warning | LZK | Fulton, Izard, Randolph, Sharp | 43 min |
| Apr 9, 3:29 PM CDT | Severe Thunderstorm Warning | SGF | Barry, Lawrence, Stone | 46 min |
| Apr 9, 3:41 PM CDT | Severe Thunderstorm Warning | SGF | Howell, Oregon, Ozark | 49 min |
| Apr 9, 3:52 PM CDT | Severe Thunderstorm Warning | SGF | Jasper, Newton | 38 min |
| Apr 9, 3:54 PM CDT | Severe Thunderstorm Warning | SGF | Barry, Lawrence | 39 min |
| Apr 9, 4:18 PM CDT | Severe Thunderstorm Warning | SGF | Jasper | 42 min |
| Apr 9, 4:24 PM CDT | Severe Thunderstorm Warning | SGF | Howell, 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, 8.2 hours before the alert went out and 55 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
- 107 J/kg
- Mixed-layer CIN
- -149 J/kg
- Mixed-layer LCL
- 1650 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 415 m²/s²
- 0-3 km storm-relative helicity
- 429 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
The text
As transmitted.
618 WWUS20 KWNS 092009 SEL9 SPC WW 092009 ARZ000-KSZ000-MOZ000-100100- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 79 NWS Storm Prediction Center Norman OK 310 PM CDT Fri Apr 9 2021 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North central Arkansas Extreme southeastern Kansas Southern Missouri * Effective this Friday afternoon and evening from 310 PM until 800 PM CDT. * Primary threats include... Scattered large hail events to 1.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...A band of storms in northern Arkansas will expand northeastward into southern Missouri through the remainder of the afternoon. The stronger storms in the band will have the potential to produce isolated large hail and damaging outflow gusts, prior to the storms weakening this evening. The severe thunderstorm watch area is approximately along and 35 statute miles north and south of a line from 10 miles southwest of Joplin MO to 45 miles east of West Plains MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 76...WW 77...WW 78... AVIATION...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 450. Mean storm motion vector 23020. ...Thompson
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 9:49 AM CDT | Mesoscale Discussion | SPC | Hempstead, Howard, Lafayette, Little River, Miller, Pike and 1 more | 116 min |
| Apr 9, 12:07 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 20 more | 6 hr |
| Apr 9, 1:25 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Chicot, Desha, Drew and 5 more | 95 min |
| Apr 9, 2:50 PM CDT | Mesoscale Discussion | SPC | Baxter, Benton, Boone, Carroll, Clay, Cleburne and 18 more | 85 min |
| Apr 9, 3:10 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Chicot, Cleveland, Desha and 5 more | 95 min |
| Apr 9, 3:14 PM CDT | Mesoscale Discussion | SPC | Benton, Crawford, Franklin, Polk, Scott, Sebastian and 2 more | 61 min |
| Apr 9, 3:42 PM CDT | Severe Thunderstorm Watch | SPC | Ashley, Chicot, Clay, Craighead, Crittenden, Cross and 6 more | 7 hr |
| Apr 9, 5:19 PM CDT | Mesoscale Discussion | SPC | Ashley | 116 min |
| Apr 9, 5:32 PM CDT | Severe Thunderstorm Watch | SPC | Columbia, Union | 7 hr |
| Apr 9, 6:34 PM CDT | Mesoscale Discussion | SPC | Benton, Carroll, Crawford, Madison, Washington | 116 min |
| Apr 9, 4:56 PM CDT | Mesoscale Discussion | SPC | Bollinger, Cape Girardeau, Carter, Madison, Perry, Sainte Genevieve and 4 more | 64 min |
Nearby
Severe Thunderstorm Watches in Missouri, 2021Severe Thunderstorm Watches in Arkansas, 2021Every severe thunderstorm 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.