Alert archive / Arkansas / Tornado Watches in 2017
Tornado Watch 16
The Storm Prediction Center issued this tornado watch at Jan 21, 2017, 3:41 PM CST for 4 states. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 21, 2017, 3:41 PM CST (21:41 UTC)
- Expired
- Jan 21, 2017, 10:16 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 60 kt
All 59 counties
Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Little River County, AR, Lonoke County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, Union County, AR, Yell County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, McCurtain County, OK, Angelina County, TX, Bowie County, TX, Cass County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX
The radar
The Shreveport radar (KSHV), 128 km from the middle of the area, began a volume at 21:43 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
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 90%
- One or more hailstones of 2 inches or more
- 60%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
38 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 21, 4:10 PM CST | Tornado Warning | SHV | Cass, Harrison, Marion | 50 min |
| Jan 21, 4:44 PM CST | Tornado Warning | SHV | Miller | 61 min |
| Jan 21, 4:49 PM CST | Severe Thunderstorm Warning | SHV | Lafayette | 56 min |
| Jan 21, 4:56 PM CST | Tornado Warning | SHV | Lafayette | 49 min |
| Jan 21, 5:03 PM CST | Severe Thunderstorm Warning | SHV | Caddo | 57 min |
| Jan 21, 5:30 PM CST | Tornado Warning | SHV | Columbia, Lafayette | 60 min |
| Jan 21, 5:31 PM CST | Severe Thunderstorm Warning | LZK | Clark, Garland, Hot Spring, Montgomery | 30 min |
| Jan 21, 5:33 PM CST | Tornado Warning | SHV | Bossier, Claiborne, Webster | 42 min |
| Jan 21, 5:34 PM CST | Severe Thunderstorm Warning | SHV | Little River | 56 min |
| Jan 21, 5:37 PM CST | Tornado Warning | SHV | Grant, Natchitoches, Winn | 38 min |
| Jan 21, 5:41 PM CST | Tornado Warning | SHV | Lafayette, Miller | 49 min |
| Jan 21, 5:46 PM CST | Severe Thunderstorm Warning | SHV | Lafayette, Miller | 44 min |
| Jan 21, 6:04 PM CST | Tornado Warning | SHV | Columbia, Union | 41 min |
| Jan 21, 6:04 PM CST | Tornado Warning | SHV | Lafayette, Miller | 56 min |
| Jan 21, 6:13 PM CST | Tornado Warning | SHV | Grant, Winn | 47 min |
| Jan 21, 6:14 PM CST | Tornado Warning | SHV | Grant, Natchitoches | 61 min |
| Jan 21, 6:16 PM CST | Severe Thunderstorm Warning | SHV | Columbia, Union | 59 min |
| Jan 21, 6:22 PM CST | Severe Thunderstorm Warning | SHV | Little River, Sevier | 53 min |
| Jan 21, 6:25 PM CST | Severe Thunderstorm Warning | SHV | Howard, Sevier | 65 min |
| Jan 21, 6:32 PM CST | Tornado Warning | SHV | Union | 43 min |
| Jan 21, 6:44 PM CST | Tornado Warning | SHV | Columbia, Union | 46 min |
| Jan 21, 6:48 PM CST | Tornado Warning | SHV | Lafayette | 57 min |
| Jan 21, 6:52 PM CST | Severe Thunderstorm Warning | SHV | LaSalle | 23 min |
| Jan 21, 7:00 PM CST | Tornado Warning | SHV | Grant, LaSalle, Winn | 22 min |
| Jan 21, 7:08 PM CST | Tornado Warning | SHV | Grant | 52 min |
| Jan 21, 7:13 PM CST | Tornado Warning | SHV | Union | 47 min |
| Jan 21, 7:16 PM CST | Severe Thunderstorm Warning | LZK | Polk | 44 min |
| Jan 21, 7:21 PM CST | Tornado Warning | SHV | Columbia, Union | 54 min |
| Jan 21, 7:25 PM CST | Severe Thunderstorm Warning | LZK | Bradley, Calhoun, Cleveland, Drew, Ouachita | 50 min |
| Jan 21, 7:33 PM CST | Tornado Warning | SHV | Union | 42 min |
| Jan 21, 7:34 PM CST | Severe Thunderstorm Warning | SHV | Union | 56 min |
| Jan 21, 7:37 PM CST | Severe Thunderstorm Warning | SHV | Columbia | 68 min |
| Jan 21, 7:39 PM CST | Tornado Warning | SHV | Union | 51 min |
| Jan 21, 7:56 PM CST | Tornado Warning | SHV | Grant, LaSalle | 64 min |
| Jan 21, 8:03 PM CST | Tornado Warning | SHV | Claiborne, Webster | 57 min |
| Jan 21, 8:05 PM CST | Severe Thunderstorm Warning | LZK | Bradley, Calhoun, Cleveland, Dallas, Drew, Grant and 1 more | 40 min |
| Jan 21, 8:21 PM CST | Tornado Warning | SHV | Union | 39 min |
| Jan 21, 8:47 PM CST | Tornado Warning | SHV | Lincoln, Union | 43 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 (KBAD), launched 12:00Z, 9.7 hours before the alert went out and 124 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
- 20 J/kg
- Mixed-layer CIN
- -323 J/kg
- Mixed-layer LCL
- 1223 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
The text
As transmitted.
308
WWUS20 KWNS 212139
SEL6
SPC WW 212139
ARZ000-LAZ000-OKZ000-TXZ000-220300-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 16
NWS Storm Prediction Center Norman OK
340 PM CST Sat Jan 21 2017
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southern Arkansas
Northern Louisiana
Extreme Southeast Oklahoma
Northeast Texas
* Effective this Saturday afternoon and evening from 340 PM until
900 PM CST.
* Primary threats include...
A few tornadoes possible
Widespread large hail and isolated very large hail events to 3
inches in diameter likely
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorms will form soon over northeast TX and spread
across the watch area this afternoon and evening. Supercells
capable of very large hail and a few tornadoes are expected.
The tornado watch area is approximately along and 75 statute miles
east and west of a line from 50 miles north northwest of Hot Springs
AR to 35 miles south southwest of Natchitoches LA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU6).
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 13...WW 14...WW 15...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 25035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 21, 2:33 PM CST | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Dallas, Hempstead, Howard and 9 more | 2 hr |
| Jan 21, 5:32 PM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 26 more | 118 min |
| Jan 20, 6:37 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 3 more | 113 min |
| Jan 20, 7:32 PM CST | Tornado Watch | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 9 more | 6 hr |
| Jan 20, 10:04 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Calcasieu, Cameron, Evangeline and 7 more | 116 min |
| Jan 20, 10:44 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Jefferson, Lafourche and 12 more | 61 min |
| Jan 20, 11:00 PM CST | Tornado Watch | SPC | Ascension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberville and 17 more | 8 hr |
| Jan 21, 1:41 AM CST | Mesoscale Discussion | SPC | Acadia, Avoyelles, Cameron, Evangeline, Iberia, Jefferson Davis and 5 more | 64 min |
| Jan 21, 2:55 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more | 2 hr |
| Jan 21, 6:35 AM CST | Mesoscale Discussion | SPC | Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more | 55 min |
| Jan 21, 2:34 PM CST | Mesoscale Discussion | SPC | Allen, Ascension, Avoyelles, Catahoula, Concordia, East Baton Rouge and 16 more | 2 hr |
| Jan 21, 3:29 PM CST | Tornado Watch | SPC | Acadia, Ascension, Avoyelles, Catahoula, Concordia, East Baton Rouge and 22 more | 6 hr |
| Jan 20, 10:07 PM CST | Mesoscale Discussion | SPC | Brazoria, Chambers, Fort Bend, Hardin, Harris, Jasper and 10 more | 113 min |
Nearby
Tornado Watches in Arkansas, 2017Tornado Watches in Louisiana, 2017Tornado Watches in Texas, 2017Every tornado watch in 2017
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.