Little Rock, AR Answer Key

Summary of the Event:

Date of Sounding: 22 January 1999 @ 00 UTC
This turned out to be a very significant tornado and large hail outbreak across much of Arkansas. From 20:30-02:00 UTC the LZK office logged 87 severe hail reports, with several reports larger than 3.00 inches (5.00 inch hail was largest). Numerous supercells were to blame for the hail reports, and the majority of the supercells were tornadic. For this event it is likely that dynamically induced vertical pressure gradients due to strong rotation within the storms siginificantly added to the hail threat, as enormous hail was produced with less than 1000 J/kg CAPE.


#13 Little Rock, Arkansas
CAPE:	Decent: 819 J/kg, no CIN
Deep Layer Shear:	Excellent: 0-6 km shear of 45 knots, good veering profile, WSW 95 knots winds at tropopause
Mid-level Lapse Rates:	Good: about the same as or better than moist adiabatic up through at least -30C
Freezing Level:	10.6 kft
Overall Threat of Severe Hail:	Moderate: Would like to see more CAPE, but rotational potential is huge with any storm that gets going. The shear is so good it's tough to not go moderate risk.
Summary of the Event: Date of Sounding: 22 January 1999 @ 00 UTC This turned out to be a very significant tornado and large hail outbreak across much of Arkansas. From 20:30-02:00 UTC the LZK office logged 87 severe hail reports, with several reports larger than 3.00 inches (5.00 inch hail was largest). Numerous supercells were to blame for the hail reports, and the majority of the supercells were tornadic. For this event it is likely that dynamically induced vertical pressure gradients due to strong rotation within the storms siginificantly added to the hail threat, as enormous hail was produced with less than 1000 J/kg CAPE.