1. Large-Hail-Producing Thunderstorms over the Midlands of South Carolina on October 21, 2005 Dan Miller NWS Columbia, SC

2. SC 25-Year Large Hail (1.75+) Climatology

3. Meteorological Environment Key Points Warm and moist low level air –Surface temperatures and dewpoints about ten degrees above normal, enhancing instability. Dry air aloft –Seen on water vapor imagery and soundings, aiding parcel buoyancy and lowering wet bulb zero height. Upper level disturbance –PVA enhancing lift, and cooling temps aloft steepening lapse rates/instability. Jet streak –Left front quadrant enhancing divergence aloft/lift Low level convergence/boundaries –source of lift

4. Jet Streak 250mb Height/Wind Speed 18Z 21-Oct-05

5. Jet Streak 250mb Height/Wind Speed 00Z 22-Oct-05

6. Upper Impulse 500mb Heights/Vorticity/Temps 18Z 21-Oct-05

7. Upper Impulse 500mb Heights/Vorticity/Temps 00Z 22-Oct-05

9. Surface Analysis 12Z 21-Oct-2005

12. LAPS Sounding Clarendon Co. 18Z

15. Clarendon County Severe Cell

22. Thank You! Dan Miller National Weather Service 2909 Aviation Way West Columbia, SC 29170 daniel.miller@noaa.gov 803-822-8133