Alert archive / Arkansas / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 545
The Storm Prediction Center issued this severe thunderstorm watch at Jul 4, 2009, 12:25 PM CDT for 26 counties in Arkansas; Howell County, Oregon County, Ozark County, Missouri; 7 counties in Oklahoma. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2009, 12:25 PM CDT (17:25 UTC)
- Expired
- Jul 4, 2009, 8:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Baxter County, AR, Boone County, AR, Carroll County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Fulton County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Randolph County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Yell County, AR, Howell County, MO, Oregon County, MO, Ozark County, MO, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 70 km from the middle of the area, began a volume at 17:26 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
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 1:52 PM CDT | Severe Thunderstorm Warning | TSA | LeFlore | 53 min |
| Jul 4, 7:07 PM CDT | Severe Thunderstorm Warning | TSA | Haskell, Latimer, LeFlore | 37 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
Norman, OK (KOUN), launched 12:00Z, 5.4 hours before the alert went out and 331 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
- 785 J/kg
- Mixed-layer CIN
- -173 J/kg
- Mixed-layer LCL
- 1666 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 164 m²/s²
- 0-3 km storm-relative helicity
- 278 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 11:52 AM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Clay, Cleburne, Conway, Craighead and 29 more | 53 min |
| Jul 4, 2:10 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Craighead, Greene | 6 hr |
| Jul 4, 3:36 PM CDT | Mesoscale Discussion | SPC | Montgomery, Polk, Scott | 54 min |
| Jul 4, 5:27 PM CDT | Mesoscale Discussion | SPC | Craighead, Mississippi | 63 min |
| Jul 4, 6:20 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Logan, Scott, Sebastian, Yell | 55 min |
| Jul 3, 11:35 PM CDT | Mesoscale Discussion | SPC | Cass, Clay, Jackson, Platte | 55 min |
| Jul 4, 12:45 PM CDT | Severe Thunderstorm Watch | SPC | Atoka, Beckham, Bryan, Caddo, Canadian, Carter and 25 more | 7 hr |
| Jul 4, 2:46 PM CDT | Mesoscale Discussion | SPC | Beckham, Greer, Harmon, Jackson, Kiowa | 59 min |
| Jul 4, 6:29 PM CDT | Mesoscale Discussion | SPC | Greer, Harmon, Jackson, Tillman | 61 min |
| Jul 4, 6:57 PM CDT | Mesoscale Discussion | SPC | Atoka, Beckham, Bryan, Caddo, Canadian, Carter and 26 more | 63 min |
Nearby
Severe Thunderstorm Watches in Arkansas, 2009Severe Thunderstorm Watches in Oklahoma, 2009Severe Thunderstorm Watches in Missouri, 2009Every severe thunderstorm watch in 2009
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.