National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
NOUS41 KBOX 221238
PNSBOX
CTZ002>004-MAZ002>024-026-RIZ001>008-230045-

Public Information Statement
National Weather Service Boston/Norton MA
838 AM EDT Mon Apr 22 2024

...SEVERE WEATHER PREPAREDNESS WEEK - DEFINITION OF A SEVERE
THUNDERSTORM...

The National Weather Service (NWS) Boston, MA has declared
April 22 through April 26 as Severe Weather Preparedness Week.
Each
day this week we will highlight a different preparedness topic.

A severe thunderstorm is defined as a thunderstorm that produces
wind gusts of at least 58 mph and/or hail 1.00 inches in diameter
or larger, the size of a quarter. Severe thunderstorms can and
occasionally do spawn tornadoes.

A Severe Thunderstorm Watch is issued by the Storm Prediction
Center in Norman, Oklahoma for large portions of the region when
the potential exists for severe thunderstorms. A severe
thunderstorm warning is issued by the local National Weather
Service forecast office, such as in Taunton, when severe
thunderstorms are imminent based on radar or already occurring
based on spotter observations.

Note that torrential downpours of rain that cause flooding are
not part of the definition of severe weather. They would prompt
the issuance of Flood or Flash Flood Warnings, but not Severe
Thunderstorm Warnings. It is important to note that frequent
lightning also is not a criterion for what is termed severe
weather. Of course, lightning can be extremely dangerous, but
every thunderstorm has lightning. That is what causes the
thunder. It is not practical to issue a warning for every
thunderstorm, thus we issue Severe Thunderstorm Warnings for
those storms that could produce large hail and/or damaging winds.

NOAA Weather radios, with warning alarm tones, will alert you
when a Severe Thunderstorm Warning is issued. However, they will
not sound an alarm for non-severe thunderstorms, which still can
produce deadly lightning. We recommend that lifeguards at beaches
and pools have hand-held lightning detectors. The same is true
for athletic coaches, camp directors, and parks and recreation
workers. Even without equipment, you can protect yourself by
moving indoors to a place of safety at the first rumble of
thunder. If you can hear the thunder, the storm is usually close
enough for you to have the potential to be struck by lightning.

For more information, visit Weather.gov/safety/thunderstorm

$$

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/NWSBoston

You can follow us on Twitter at
@NWSBoston