Alert archive / Arkansas / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 296
The Storm Prediction Center issued this severe thunderstorm watch at Jul 20, 2018, 9:08 PM CDT for 38 counties in Arkansas; East Carroll Parish, Morehouse Parish, West Carroll Parish, Louisiana; 19 counties in Mississippi. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 20, 2018, 9:08 PM CDT (02:08 UTC)
- Expired
- Jul 21, 2018, 2:36 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 55 kt
All 60 counties
Arkansas County, AR, Ashley County, AR, Baxter County, AR, Boone County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Johnson County, AR, Lincoln County, AR, Logan County, AR, Lonoke County, AR, Marion County, AR, Monroe County, AR, Newton County, AR, Ouachita County, AR, Perry County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Searcy County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, East Carroll Parish, LA, Morehouse Parish, LA, West Carroll Parish, LA, Attala County, MS, Bolivar County, MS, Carroll County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Leake County, MS, Leflore County, MS, Madison County, MS, Montgomery County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS
The radar
The Little Rock radar (KLZK), 90 km from the middle of the area, began a volume at 02:12 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
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- 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
- 80%
Warnings issued inside it
25 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:36 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe, Prairie | 39 min |
| Jul 20, 9:37 PM CDT | Severe Thunderstorm Warning | LZK | Monroe | 53 min |
| Jul 20, 9:44 PM CDT | Severe Thunderstorm Warning | LZK | Faulkner, Jefferson, Lonoke, Prairie, Pulaski | 46 min |
| Jul 20, 9:54 PM CDT | Tornado Warning | LZK | Arkansas, Monroe | 36 min |
| Jul 20, 10:16 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe, Prairie | 29 min |
| Jul 20, 10:19 PM CDT | Tornado Warning | LZK | Arkansas, Desha, Monroe | 26 min |
| Jul 20, 10:27 PM CDT | Severe Thunderstorm Warning | LZK | Lonoke, Pulaski | 20 min |
| Jul 20, 10:31 PM CDT | Tornado Warning | JAN | Bolivar | 45 min |
| Jul 20, 10:43 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe, Prairie | 32 min |
| Jul 20, 11:07 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe | 23 min |
| Jul 20, 11:28 PM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Desha, Monroe | 47 min |
| Jul 20, 11:44 PM CDT | Severe Thunderstorm Warning | JAN | Bolivar | 50 min |
| Jul 21, 12:19 AM CDT | Severe Thunderstorm Warning | LZK | Boone, Marion, Newton, Searcy | 41 min |
| Jul 21, 12:27 AM CDT | Severe Thunderstorm Warning | LZK | Lonoke, Prairie | 48 min |
| Jul 21, 12:48 AM CDT | Severe Thunderstorm Warning | LZK | Johnson, Newton | 57 min |
| Jul 21, 12:53 AM CDT | Severe Thunderstorm Warning | LZK | Lonoke | 37 min |
| Jul 21, 1:03 AM CDT | Severe Thunderstorm Warning | LZK | Marion, Newton, Pope, Searcy, Stone, Van Buren | 46 min |
| Jul 21, 1:09 AM CDT | Severe Thunderstorm Warning | LZK | Arkansas, Monroe, Prairie | 36 min |
| Jul 21, 1:14 AM CDT | Severe Thunderstorm Warning | LZK | Baxter, Marion, Searcy, Stone | 46 min |
| Jul 21, 1:22 AM CDT | Severe Thunderstorm Warning | LZK | Cleburne, White | 23 min |
| Jul 21, 1:29 AM CDT | Severe Thunderstorm Warning | LZK | Johnson, Logan | 34 min |
| Jul 21, 1:36 AM CDT | Severe Thunderstorm Warning | LZK | Cleburne, Independence, Pope, Van Buren | 38 min |
| Jul 21, 1:38 AM CDT | Severe Thunderstorm Warning | LZK | Prairie, White, Woodruff | 37 min |
| Jul 21, 1:51 AM CDT | Severe Thunderstorm Warning | LZK | Lonoke, Prairie, White | 24 min |
| Jul 21, 2:09 AM CDT | Severe Thunderstorm Warning | LZK | Lonoke, Prairie, White | 36 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
Little Rock, AR (KBYH), launched 00:00Z, 2.1 hours before the alert went out and 188 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
- 3694 J/kg
- Mixed-layer CIN
- -94 J/kg
- Mixed-layer LCL
- 1760 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 220 m²/s²
- 0-3 km storm-relative helicity
- 407 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 28.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:26 PM CDT | Mesoscale Discussion | SPC | Benton | 94 min |
| Jul 20, 10:20 PM CDT | Mesoscale Discussion | SPC | Arkansas, Cleveland, Craighead, Crittenden, Cross, Desha and 14 more | 115 min |
| Jul 21, 1:38 AM CDT | Mesoscale Discussion | SPC | Crittenden, Lee, Mississippi, Phillips | 67 min |
| Jul 21, 2:33 AM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Ashley, Benton, Bradley, Calhoun, Chicot and 37 more | 4 hr |
| Jul 21, 3:41 AM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Benton, Bradley, Calhoun, Chicot and 38 more | 2 hr |
| Jul 21, 6:16 AM CDT | Mesoscale Discussion | SPC | Attala, Carroll, Choctaw, Grenada, Holmes, Humphreys and 9 more | 119 min |
Nearby
Severe Thunderstorm Watches in Arkansas, 2018Severe Thunderstorm Watches in Mississippi, 2018Severe Thunderstorm Watches in Louisiana, 2018Every severe thunderstorm watch in 2018
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.