Alert archive / Arkansas / Tornado Watches in 2010

Tornado Watch 652

September 9, 201010 counties in Arkansas; Dunklin County, Pemiscot County, Missouri; 8 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Sep 9, 2010, 6:26 PM CDT for 10 counties in Arkansas; Dunklin County, Pemiscot County, Missouri; 8 counties in Tennessee. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Sep 9, 2010, 6:26 PM CDT (23:26 UTC)
Expired
Sep 9, 2010, 9:42 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lawrence County, AR, Mississippi County, AR, Poinsett County, AR, Randolph County, AR, St. Francis County, AR, Dunklin County, MO, Pemiscot County, MO, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Haywood County, TN, Lauderdale County, TN, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 83 km from the middle of the area, began a volume at 23:29 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
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
10%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
30%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 9, 6:29 PM CDTTornado WarningMEGCraighead, Greene28 min
Sep 9, 7:41 PM CDTTornado WarningMEGCraighead, Mississippi, Poinsett34 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 (KLZK), launched 12:00Z, 11.4 hours before the alert went out and 128 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-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2010-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 729 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2010-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
729 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
574 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 9:52 PM CDTMesoscale DiscussionSPCClark, Hempstead, Howard, Little River, Montgomery, Nevada and 4 more113 min
Sep 8, 10:12 PM CDTTornado WatchSPCClark, Conway, Dallas, Faulkner, Garland, Grant and 11 more4 hr
Sep 9, 3:05 PM CDTMesoscale DiscussionSPCCleburne, Independence, Newton, Searcy, Stone, Van Buren and 1 more55 min
Sep 9, 4:39 PM CDTMesoscale DiscussionSPCCleburne, Conway, Craighead, Crittenden, Cross, Faulkner and 13 more96 min

Nearby

Tornado Watches in Arkansas, 2010Tornado Watches in Tennessee, 2010Tornado Watches in Missouri, 2010Every tornado watch in 2010

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.