Summer Storms + Tornadoes  

Summer Storms + Tornadoes

Summer Storms and Tornadoes can bring torrential rains, damaging winds, dangerous lighting, and large hail. Furthermore, due to the complex nature of these storms, the affected area from an event could be very small, perhaps only a few blocks within a single town, or a system could impact multiple communities. Severe summer storms include tornadoes, downburst, lightning, high winds, heavy rain and hail. These weather systems can cause flash floods, as well as, downed trees and power lines.

The possible weather events are:

Summer Storms: To help warn residents to the arrival of potentially severe and destructive storms systems the National Weather Service utilizes a system of watches and warnings to designate the potential for damaging weather. The following definitions are pulled directly from the National Oceanic and Atmospheric Administration’s webpage.

  • Severe Thunderstorm Watch: Episodes of hail one inch in diameter or larger, and/or damaging winds are expected during a three-to-eight hour period. Winds for a severe thunderstorm are in excess of 58 miles per hour or 50 knots. Typical watches cover about 25,000 square miles.
  • Severe Thunderstorm Warning: Episodes of hail one inch in diameter or larger, and/or damaging thunderstorm winds have developed and are occurring, or are imminent. Winds are in excess of 58 miles per hour or in excess of 50 knots. Unlike a watch, a Severe Thunderstorm Warning is generally only issued for small areas where the severe weather is likely to impact the region in the very near future.

Hail: Hail has the potential to be extremely devastating; with hail above an inch in diameter capable causing significant damage to crops, persons, and property. While correlations can be drawn between the presence of hail and a tornado hail does not mean a tornado is imminent nor does its absence mean there is no risk of a tornado.

Lightning: Lightning is an exceptionally dangerous hazard that is most commonly associated with thunderstorms. Lightning typically occurs in two different forms. Intra-cloud lightning occurs between oppositely charged particles within the thunderstorm cloud structure. Because the discharge occurs within the cloud structure, it poses little threat to human life or destruction of property. The second form of lightning is cloud-to-ground lightning. This form occurs either between negatively charged particles at the base of the cloud and positively charged particles on the ground; or positively charged particles at the top of the thunderstorm structure and negatively charged particles on the ground. Cloud-to-ground lightning can pose a great threat to both human life and property.

Downbursts: Downbursts are a severe weather occurrence that occasionally accompanies a severe thunderstorm. A downburst develops when large portions of unstable air mass begin to fall, creating a downdraft. These straight line winds can easily exceed 100mph.

Tornadoes: Tornadoes are the product of a severe thunderstorm that has progressed in such a way to produce the low level rotation needed for tornado development. On a localized basis, tornadoes are the most destructive of all atmospheric phenomena. Wind speeds of 65-85 mph are associated with the least intense tornadoes while winds over 200 mph are associated with the most intense.