Alert archive / Arkansas / Tornado Watches in 2020
Tornado Watch 481
The Storm Prediction Center issued this tornado watch at Sep 1, 2020, 3:17 PM CDT for 22 counties in Arkansas. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 1, 2020, 3:17 PM CDT (20:17 UTC)
- Expired
- Sep 1, 2020, 6:50 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 55 kt
All 22 counties
Arkansas County, AR, Cleburne County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Grant County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lee County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR
The radar
The Little Rock radar (KLZK), 54 km from the middle of the area, began a volume at 20:18 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
- 10%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 40%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 3:30 PM CDT | Tornado Warning | LZK | Cleburne, Independence, Jackson, White | 45 min |
| Sep 1, 3:35 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Jefferson, Lonoke | 40 min |
| Sep 1, 3:39 PM CDT | Severe Thunderstorm Warning | LZK | Grant, Jefferson, Lonoke, Pulaski, Saline | 51 min |
| Sep 1, 4:10 PM CDT | Severe Thunderstorm Warning | LZK | Independence, Jackson | 50 min |
| Sep 1, 4:13 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Lonoke, Prairie | 32 min |
| Sep 1, 4:25 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe | 50 min |
| Sep 1, 4:30 PM CDT | Severe Thunderstorm Warning | LZK | Jackson, White, Woodruff | 45 min |
| Sep 1, 4:56 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Desha, Jefferson, Lincoln | 34 min |
| Sep 1, 5:32 PM CDT | Severe Thunderstorm Warning | MEG | Cross, Poinsett | 26 min |
| Sep 1, 6:05 PM CDT | Severe Thunderstorm Warning | MEG | Lee, Phillips | 40 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, 8.3 hours before the alert went out and 295 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
- 38 J/kg
- Mixed-layer CIN
- -101 J/kg
- Mixed-layer LCL
- 987 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- -22 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
363 WWUS20 KWNS 012014 SEL1 SPC WW 012014 ARZ000-020000- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 481 NWS Storm Prediction Center Norman OK 315 PM CDT Tue Sep 1 2020 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and eastern Arkansas * Effective this Tuesday afternoon and evening from 315 PM until 700 PM CDT. * Primary threats include... A couple tornadoes possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Long-lived supercell embedded within a cluster across north-central Arkansas may continue east in northeast Arkansas, while a supercell near/south of Little Rock may persist east across east-central Arkansas. The tornado watch area is approximately along and 65 statute miles east and west of a line from 5 miles east of Pine Bluff AR to 15 miles northwest of Jonesboro AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 24030. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 2:10 PM CDT | Mesoscale Discussion | SPC | Cleburne, Craighead, Crittenden, Cross, Faulkner, Garland and 16 more | 65 min |
| Sep 1, 5:47 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clay, Cleburne, Cleveland, Craighead, Crittenden and 28 more | 88 min |
Nearby
Tornado Watches in Arkansas, 2020Every tornado watch in 2020
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.