Alert archive / Texas / Tornado Watches in 2021
Tornado Watch 555
The Storm Prediction Center issued this tornado watch at Dec 10, 2021, 6:34 PM CST for 8 counties in Arkansas; McCurtain County, Oklahoma; 10 counties in Texas. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 6:34 PM CST (00:34 UTC)
- Expired
- Dec 10, 2021, 11:00 PM CST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Marion County, TX, Morris County, TX, Red River County, TX, Titus County, TX, Upshur County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 143 km from the middle of the area, began a volume at 00:33 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
- 50%
- One or more EF2 to EF5 tornadoes
- 40%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 7:05 PM CST | Severe Thunderstorm Warning | SHV | Little River, Sevier | 55 min |
| Dec 10, 7:30 PM CST | Severe Thunderstorm Warning | SHV | Hempstead, Howard, Little River, Nevada, Sevier | 45 min |
| Dec 10, 8:00 PM CST | Severe Thunderstorm Warning | SHV | Hempstead, Howard, Little River, Sevier | 45 min |
| Dec 10, 8:28 PM CST | Severe Thunderstorm Warning | SHV | Hempstead, Howard, Nevada | 62 min |
| Dec 10, 9:08 PM CST | Flash Flood Warning | SHV | Hempstead | 4 hr |
| Dec 10, 9:22 PM CST | Severe Thunderstorm Warning | SHV | Hempstead, Nevada | 29 min |
| Dec 10, 10:20 PM CST | Severe Thunderstorm Warning | SHV | Little River, Miller | 55 min |
| Dec 10, 10:53 PM CST | Severe Thunderstorm Warning | SHV | Camp, Cass, Harrison, Marion, Morris, Titus and 1 more | 67 min |
| Dec 10, 10:58 PM CST | Severe Thunderstorm Warning | SHV | Hempstead, Lafayette, Nevada | 62 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
Shreveport, LA (KSHV), launched 00:00Z, 0.6 hours before the alert went out and 142 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
- 1338 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 1005 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 243 m²/s²
- 0-3 km storm-relative helicity
- 334 m²/s²
- Significant tornado parameter
- 2.6
- Supercell composite
- 10.4
The text
As transmitted.
147
WWUS20 KWNS 110030
SEL5
SPC WW 110030
ARZ000-OKZ000-TXZ000-110500-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 555
NWS Storm Prediction Center Norman OK
635 PM CST Fri Dec 10 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southwest Arkansas
Far southeast Oklahoma
Northeast Texas
* Effective this Friday evening from 635 PM until 1100 PM CST.
* Primary threats include...
A few tornadoes and a couple intense tornadoes possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Isolated damaging wind gusts to 70 mph possible
SUMMARY...Discrete supercell should intensify as it impinges on
greater low-level shear near the Texarkana area, with a strong
tornado possible as it spreads across southwest Arkansas. Additional
storms will form along the cold front later this evening with mainly
a wind/hail threat.
The tornado watch area is approximately along and 60 statute miles
east and west of a line from 25 miles northeast of De Queen AR to 60
miles southwest of Texarkana AR. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU5).
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 552...WW 553...WW 554...
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 450. Mean
storm motion vector 24035.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 6:22 PM CST | Mesoscale Discussion | SPC | Craighead, Greene, Jackson, Mississippi, Poinsett | 53 min |
| Dec 10, 6:37 PM CST | Mesoscale Discussion | SPC | Baxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more | 83 min |
| Dec 10, 6:51 PM CST | Tornado Watch | SPC | Baxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more | 4 hr |
| Dec 10, 7:34 PM CST | Mesoscale Discussion | SPC | Clark, Crittenden, Cross, Faulkner, Garland, Grant and 16 more | 86 min |
| Dec 10, 7:54 PM CST | Mesoscale Discussion | SPC | Boone, Carroll, Crawford, Franklin, Johnson, Logan and 7 more | 2 hr |
| Dec 10, 9:40 PM CST | Mesoscale Discussion | SPC | Arkansas, Clark, Cleveland, Craighead, Crittenden, Cross and 13 more | 2 hr |
| Dec 10, 10:00 PM CST | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 5 more | 90 min |
| Dec 10, 10:09 PM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 17 more | 96 min |
| Dec 10, 10:44 PM CST | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 16 more | 6 hr |
| Dec 11, 2:00 AM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Desha and 4 more | 90 min |
| Dec 11, 1:36 AM CST | Mesoscale Discussion | SPC | Angelina, Austin, Brazos, Burleson, Cherokee, Colorado and 23 more | 114 min |
| Dec 11, 4:02 AM CST | Mesoscale Discussion | SPC | Hardin, Jasper, Liberty, Montgomery, Newton, Orange and 5 more | 118 min |
Nearby
Tornado Watches in Texas, 2021Tornado Watches in Arkansas, 2021Tornado Watches in Oklahoma, 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.