Alert archive / Arkansas / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 575
The Storm Prediction Center issued this severe thunderstorm watch at Aug 12, 2012, 10:49 PM CDT for 22 counties in Arkansas; Barry County, McDonald County, Missouri; 13 counties in Oklahoma. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 12, 2012, 10:49 PM CDT (03:49 UTC)
- Expired
- Aug 13, 2012, 4:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 37 counties
Benton County, AR, Boone County, AR, Carroll County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Garland County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Polk County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Barry County, MO, McDonald County, MO, Adair County, OK, Cherokee County, OK, Craig County, OK, Delaware County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, Mayes County, OK, McIntosh County, OK, Muskogee County, OK, Ottawa County, OK, Pittsburg County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 74 km from the middle of the area, began a volume at 03:52 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
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 11:05 PM CDT | Severe Thunderstorm Warning | TSA | Ottawa | 25 min |
| Aug 12, 11:07 PM CDT | Severe Thunderstorm Warning | TSA | Benton, Washington | 53 min |
| Aug 12, 11:11 PM CDT | Severe Thunderstorm Warning | TSA | Crawford, Washington | 37 min |
| Aug 12, 11:15 PM CDT | Severe Thunderstorm Warning | SGF | McDonald, Newton | 20 min |
| Aug 12, 11:16 PM CDT | Severe Thunderstorm Warning | TSA | Craig, Mayes | 13 min |
| Aug 12, 11:30 PM CDT | Severe Thunderstorm Warning | TSA | Benton, Washington | 25 min |
| Aug 12, 11:36 PM CDT | Severe Thunderstorm Warning | TSA | Crawford, Franklin, Sebastian | 54 min |
| Aug 13, 12:22 AM CDT | Severe Thunderstorm Warning | LZK | Johnson, Logan | 38 min |
| Aug 13, 1:01 AM CDT | Severe Thunderstorm Warning | LZK | Johnson, Logan, Pope, Yell | 44 min |
| Aug 13, 1:05 AM CDT | Severe Thunderstorm Warning | LZK | Logan, Scott | 40 min |
| Aug 13, 1:32 AM CDT | Severe Thunderstorm Warning | LZK | Conway, Logan, Perry, Pope, Yell | 58 min |
| Aug 13, 2:23 AM CDT | Severe Thunderstorm Warning | LZK | Conway, Faulkner, Perry, Pulaski | 67 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
Springfield, MO (KSGF), launched 00:00Z, 3.8 hours before the alert went out and 115 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
- 338 J/kg
- Mixed-layer CIN
- -106 J/kg
- Mixed-layer LCL
- 1933 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 328 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 10:26 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Howard, Little River, Logan, Montgomery and 5 more | 94 min |
| Aug 13, 1:45 AM CDT | Mesoscale Discussion | SPC | Arkansas, Baxter, Benton, Boone, Carroll, Cleburne and 36 more | 2 hr |
| Aug 13, 7:48 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Chicot, Cleveland, Desha, Drew | 87 min |
| Aug 13, 3:15 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Chicot, Crittenden, Cross and 9 more | 30 min |
| Aug 13, 3:32 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Chicot, Crittenden, Cross, Desha, Drew and 7 more | 7 hr |
| Aug 12, 7:16 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Choctaw, Haskell, Latimer, LeFlore and 6 more | 4 hr |
| Aug 12, 8:41 PM CDT | Mesoscale Discussion | SPC | Bryan, Choctaw, Pushmataha | 64 min |
Nearby
Severe Thunderstorm Watches in Arkansas, 2012Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Missouri, 2012Every severe thunderstorm watch in 2012
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.