Alert archive / Arkansas / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 156
The Storm Prediction Center issued this severe thunderstorm watch at Apr 22, 2017, 12:41 AM CDT for 4 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 22, 2017, 12:41 AM CDT (05:41 UTC)
- Expired
- Apr 22, 2017, 6:42 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 64 counties
Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lafayette County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Miller County, AR, Monroe County, AR, Nevada County, AR, Ouachita County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Red River Parish, LA, Union Parish, LA, Webster Parish, LA, Bolivar County, MS, Coahoma County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tunica County, MS, Washington County, MS, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 94 km from the middle of the area, began a volume at 05:45 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
- 20%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 40%
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 |
|---|---|---|---|---|
| Apr 22, 2:48 AM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Cleveland, Desha, Jefferson, Lincoln | 42 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 00:00Z, 5.7 hours before the alert went out and 88 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
- 828 J/kg
- Mixed-layer CIN
- -29 J/kg
- Mixed-layer LCL
- 1486 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 143 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 7:11 PM CDT | Mesoscale Discussion | SPC | Howard, Little River, Montgomery, Pike, Polk, Scott and 3 more | 94 min |
| Apr 21, 9:28 PM CDT | Mesoscale Discussion | SPC | Garland, Hempstead, Howard, Little River, Miller, Montgomery and 5 more | 92 min |
| Apr 21, 11:39 PM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Dallas, Garland, Hempstead and 13 more | 96 min |
| Apr 22, 4:16 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 3 more | 89 min |
| Apr 22, 12:51 PM CDT | Mesoscale Discussion | SPC | Chicot | 114 min |
| Apr 22, 4:56 PM CDT | Mesoscale Discussion | SPC | Madison, Tensas | 64 min |
| Apr 22, 3:08 PM CDT | Severe Thunderstorm Watch | SPC | Attala, Carroll, Chickasaw, Choctaw, Clay, Holmes and 16 more | 4 hr |
Nearby
Severe Thunderstorm Watches in Arkansas, 2017Severe Thunderstorm Watches in Texas, 2017Severe Thunderstorm Watches in Louisiana, 2017Every severe thunderstorm 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.