Alert archive / Arkansas / Tornado Watches in 2021
Tornado Watch 27
The Storm Prediction Center issued this tornado watch at Mar 17, 2021, 7:47 AM CDT for 21 counties in Arkansas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 17, 2021, 7:47 AM CDT (12:47 UTC)
- Expired
- Mar 17, 2021, 1:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 21 counties
Calhoun County, AR, Clark County, AR, Conway County, AR, Dallas County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Johnson County, AR, Logan County, AR, Montgomery County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Van Buren County, AR, Yell County, AR
The radar
The Little Rock radar (KLZK), 62 km from the middle of the area, began a volume at 12:46 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
- 70%
- One or more EF2 to EF5 tornadoes
- 50%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 10:27 AM CDT | Flash Flood Warning | LZK | Pulaski | 3 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
Shreveport, LA (KSHV), launched 12:00Z, 0.8 hours before the alert went out and 258 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
- 1417 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 682 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 328 m²/s²
- 0-3 km storm-relative helicity
- 340 m²/s²
- Significant tornado parameter
- 2.7
- Supercell composite
- 14.5
The text
As transmitted.
503
WWUS20 KWNS 171243
SEL7
SPC WW 171243
ARZ000-171800-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 27
NWS Storm Prediction Center Norman OK
745 AM CDT Wed Mar 17 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
western and central Arkansas
* Effective this Wednesday morning and afternoon from 745 AM
until 100 PM CDT.
* Primary threats include...
A few tornadoes likely with a couple intense tornadoes possible
Scattered large hail likely with isolated very large hail events
to 2 inches in diameter possible
Scattered damaging wind gusts to 70 mph likely
SUMMARY...Strong/severe storms are forecast to spread northeastward
across the Arklatex and into western and central Arkansas over the
next couple of hours. In addition to potential for hail and locally
damaging winds, risk for a couple of tornadoes is also evident.
The tornado watch area is approximately along and 50 statute miles
east and west of a line from 50 miles north of Hot Springs AR to 35
miles south of Hot Springs AR. 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 24...WW 25...WW 26...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 22035.
...GossSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 12:45 AM CDT | Mesoscale Discussion | SPC | Benton, Washington | 90 min |
| Mar 17, 1:32 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more | 118 min |
| Mar 17, 4:04 AM CDT | Mesoscale Discussion | SPC | Columbia, Hempstead, Lafayette, Little River, Miller, Sevier | 86 min |
| Mar 17, 4:37 AM CDT | Severe Thunderstorm Watch | SPC | Hempstead, Howard, Lafayette, Little River, Miller, Nevada and 1 more | 5 hr |
| Mar 17, 5:34 AM CDT | Mesoscale Discussion | SPC | Arkansas, Crittenden, Cross, Desha, Lee, Lincoln and 3 more | 86 min |
| Mar 17, 5:53 AM CDT | Tornado Watch | SPC | Arkansas, Bradley, Cleveland, Crittenden, Desha, Drew and 8 more | 7 hr |
| Mar 17, 6:40 AM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Crawford, Dallas, Franklin and 19 more | 95 min |
| Mar 17, 7:38 AM CDT | Mesoscale Discussion | SPC | Crittenden, Lee, Monroe, Phillips, St. Francis | 67 min |
| Mar 17, 8:43 AM CDT | Tornado Watch | SPC | Columbia, Union | 4 hr |
| Mar 17, 12:15 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew, Phillips | 90 min |
| Mar 17, 12:57 PM CDT | Tornado Watch | SPC | Ashley, Chicot, Lee, Phillips | 6 hr |
| Mar 17, 1:18 PM CDT | Mesoscale Discussion | SPC | Benton, Boone, Carroll, Clark, Crawford, Franklin and 22 more | 57 min |
| Mar 17, 2:00 PM CDT | Tornado Watch | SPC | Benton, Boone, Carroll, Crawford, Franklin, Johnson and 12 more | 7 hr |
| Mar 17, 2:56 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew | 94 min |
| Mar 17, 3:37 PM CDT | Mesoscale Discussion | SPC | Baxter, Benton, Boone, Carroll, Crawford, Franklin and 5 more | 83 min |
| Mar 17, 6:09 PM CDT | Mesoscale Discussion | SPC | Crittenden, Cross | 66 min |
Nearby
Tornado Watches in Arkansas, 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.