Holy Crap

I was Googling some stuff in Rapid City and a new line popped up on the left menu list. It was a Google Public Alert that directed me to this National Weather Service Severe Thunderstorm Warning:

Severe Thunderstorm Warning
THE NATIONAL WEATHER SERVICE IN RAPID CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTH CENTRAL CUSTER COUNTY IN SOUTHWESTERN SOUTH DAKOTA...
CENTRAL PENNINGTON COUNTY IN WEST CENTRAL SOUTH DAKOTA...

* UNTIL 530 PM MDT

* AT 407 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE HAIL.
THIS STORM WAS LOCATED NEAR SHERIDAN LAKE...OR 9 MILES NORTHEAST OF HILL CITY...AND MOVING SOUTHEAST AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
MOUNT RUSHMORE...KEYSTONE...ROCKERVILLE...CENTER LAKE...HAYWARD... CUSTER PARK GAME LODGE AND HERMOSA.

...HAIL <50MPH 1.50IN


Instructions:
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

These locations are about ten miles south of us but the sky is black and I can hear thunder rolling far away. We are sitting here watching it evolve...