Alert archive / Arkansas / Severe Thunderstorm Watches in 2008

Severe Thunderstorm Watch 943

December 9, 200830 counties in Arkansas; 17 counties in Missouri; 8 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Dec 9, 2008, 12:22 AM CST for 30 counties in Arkansas; 17 counties in Missouri; 8 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Dec 9, 2008, 12:22 AM CST (06:22 UTC)
Expired: Dec 9, 2008, 4:11 AM CST
In force: 4 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 55 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Independence County, AR, Izard 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, Sharp County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, White County, AR, Yell County, AR, Barry County, MO, Christian County, MO, Dent County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO, Adair County, OK, Cherokee County, OK, Delaware County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, Ottawa County, OK, Sequoyah County, OK

The radar

The Springfield radar (KSGF), 118 km from the middle of the area, began a volume at 06:22 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: 50%
One or more gusts of 65 knots or more: 30%
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

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Dec 9, 12:48 AM CST	Severe Thunderstorm Warning	TSA	Benton, Washington	57 min
Dec 9, 12:52 AM CST	Severe Thunderstorm Warning	TSA	Haskell, Sequoyah	23 min
Dec 9, 12:55 AM CST	Severe Thunderstorm Warning	SGF	Newton	28 min
Dec 9, 1:00 AM CST	Severe Thunderstorm Warning	SGF	Barry	57 min
Dec 9, 1:22 AM CST	Severe Thunderstorm Warning	TSA	Washington	41 min
Dec 9, 2:37 AM CST	Severe Thunderstorm Warning	LZK	Polk, Scott	38 min
Dec 9, 2:58 AM CST	Severe Thunderstorm Warning	LZK	Polk	32 min
Dec 9, 3:16 AM CST	Severe Thunderstorm Warning	LZK	Scott	14 min
Dec 9, 3:29 AM CST	Severe Thunderstorm Warning	LZK	Polk, Scott	61 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, 6.4 hours before the alert went out and 81 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 809 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 648 m²/s²
0-3 km storm-relative helicity: 738 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 8, 11:31 PM CST	Tornado Watch	SPC	Little River, Miller	7 hr
Dec 9, 12:10 AM CST	Mesoscale Discussion	SPC	Benton, Boone, Carroll, Madison, Marion, Newton and 1 more	35 min
Dec 9, 1:20 AM CST	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Conway and 25 more	25 min
Dec 9, 2:17 AM CST	Mesoscale Discussion	SPC	Little River, Miller	58 min
Dec 9, 3:41 AM CST	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Clark, Cleveland, Columbia and 36 more	64 min
Dec 9, 4:11 AM CST	Tornado Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more	7 hr
Dec 9, 7:41 AM CST	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 21 more	64 min
Dec 9, 9:32 AM CST	Tornado Watch	SPC	Ashley, Bradley, Chicot, Desha, Drew, Union	6 hr
Dec 9, 10:12 AM CST	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 10 more	93 min
Dec 9, 2:18 PM CST	Mesoscale Discussion	SPC	Chicot	87 min
Dec 8, 7:10 PM CST	Mesoscale Discussion	SPC	Bryan, Carter, Love, Marshall	2 hr

Nearby

Severe Thunderstorm Watches in Arkansas, 2008 Severe Thunderstorm Watches in Missouri, 2008 Severe Thunderstorm Watches in Oklahoma, 2008 Every severe thunderstorm watch in 2008

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.