Large-Hail-Producing Thunderstorms over the Midlands of South Carolina on October 21, 2005
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Transcript of Large-Hail-Producing Thunderstorms over the Midlands of South Carolina on October 21, 2005
Large-Hail-Producing Thunderstorms over the Midlands of South Carolina
on October 21, 2005
Dan MillerNWS Columbia, SC
SC 25-Year Large Hail (1.75”+) Climatology
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J F M A M J J A S O N D
SC Hail Events(1.75"+) since 1980
Meteorological EnvironmentKey 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
Jet Streak250mb Height/Wind Speed
18Z 21-Oct-05
Jet Streak250mb Height/Wind Speed
00Z 22-Oct-05
Upper Impulse500mb Heights/Vorticity/Temps
18Z 21-Oct-05
Upper Impulse500mb Heights/Vorticity/Temps
00Z 22-Oct-05
Surface Analysis12Z 21-Oct-2005
LAPS Sounding Clarendon Co. 18Z
Clarendon County Severe Cell
Thank You!
Dan MillerNational Weather Service2909 Aviation WayWest Columbia, SC 29170