(Much of the information on this page is adapted from information provided by the American Red Cross, FEMA and the National Weather Service).
- What to do Before
- Basic Preparedness
- Listen for Severe Thunderstorm Watches and Warnings
- Estimating the Distance of a Thunderstorm, and "The 30/30 Rule"
Track color-coded maps with New Jersey's real-time NWS weather forecasts, shore, tidal and river information:
Listen to NOAA Weather Radio or a local news
source for weather information and for instructions from public
safety officials. Remember: A battery-powered radio
is a vital part of your Emergency
Thunderstorms can occur any time of year in New Jersey.
However, severe thunderstorms generally occur during the warmer
months of March through October.
A typical thunderstorm is 15 miles in diameter and lasts
an average of 30 minutes - far smaller than a hurricane or
a winter storm. Despite their small size, however, ALL
thunderstorms are dangerous.
Thunderstorms can produce LIGHTNING, TORNADOES, STRONG
WINDS, FLASH FLOODING and HAIL.
LIGHTNING occurs with all thunderstorms. Each year,
lightning causes an average of 67 fatalities nationwide. Many
more are injured but survive with long-term, debilitating
symptoms including memory loss, sleep disorders and muscle
TORNADOES produce winds in excess of 250 miles per
hour. They can be a mile wide and stay on the ground over
50 miles. For more information see NJOEM's Tornado
STRONG WINDS caused by a thunderstorm can exceed 100
mph and cause damage equal to a tornado. They can be extremely
dangerous to aviation.
FLASH FLOODING is the number one cause of death associated
with thunderstorms, causing more than 140 fatalities each
year. Fore more information see NJOEM's Flood
and Flash Flood Preparedness page.
HAIL causes more than $1 billion in crop and property
damage each year nationwide.
Of the estimated 100,000 thunderstorms that occur each year
in the United States, about 10 percent are classified as
severe. The National Weather Service considers a thunderstorm
severe if it produces hail at least ¾-inch in diameter, winds
of 58 mph or stronger, or a tornado.
Follow these Links
for much more information on preparedness and on the science
of thunderstorms and lightning.