... South Dakota severe weather awareness week... day two
... Severe weather watches and warnings...
are issued when conditions are favorable for tornadoes... severe
thunderstorms or flash floods. If you are in a watch
area... continue with normal activities... but also make plans to
seek shelter if necessary.
are issued when severe weather has been reported or is imminent.
Seek shelter immediately if you are in or near the path of the
storm. Warnings are issued by County and city names. Make sure you
know the name of the County in which you live and the cities that
the forecast and warning process begins one or more days ahead of
time... when the threat area is determined. Hazardous weather
outlooks are issued early every morning... and are updated as
If a watch is issued...
local weather offices are staffed with extra personnel. State
officials are notified... and they pass information to the County
and local level. Counties and cities activate their spotter groups
as the threat increases.
TV and radio stations pass the word to the public.
If a warning is issued...
warnings are disseminated swiftly in a multitude of
ways... including TV... radio and over the internet. Advances in
technology have allowed people to receive warnings via wireless
devices. Spotters provide important reports on the storm... and
emergency officials carry out the plans that the emergency
managers have developed. Updates are issued frequently until the
immediate threat has ended.
counties and cities own the sirens and therefore decide how and
when to activate them. The National Weather Service does not
sound them. There are many different policies by counties and
cities. Some will activate sirens across the entire County for a
Tornado Warning only. Others will activate sirens countywide for
tornado warnings and all severe thunderstorm warnings. Some will
activate sirens across the entire County for tornado warnings and
severe thunderstorms that have winds of at least 70 or 75 mph.
Others will activate sirens only for portions of counties. Also
local officials may sound the sirens anytime they believe severe
weather is a threat... even if there is no warning from the
National Weather Service.
Sirens normally sound about three minutes then go silent. It is
very rare to keep the sirens sounding for the entire warning
since that will cause the backup battery to run out... which would
be critical in the event power GOES out. Furthermore... the Siren
motor will fail much more quickly if the Siren sounds
continuously. Some jurisdictions may repeat Siren activation every
few minutes. There is no such thing as an all clear for storms.
A quick way of reaching many people is through the emergency alert
system. Media outlets receive the warning information and
disseminate it to you... often by interrupting programming. Many
television stations use a crawl and other visual means.
Advances in technology have allowed watches and warnings to be
received via wireless devices such as phones and tablets. The
major cell phone carriers are also ingesting NWS warnings and
retransmitting them to their towers in the affected areas. Smart
phones capable of receiving this alert will sound an alarm
notifying you of the Tornado Warning.
Finally... the tone alert feature of NOAA Weather Radio will also
activate specially built receivers... sounding an alarm to alert
you to the danger. It sounds its alert anytime the National
Weather Service issues a warning... even in the middle of the
night. Make sure you have a NOAA Weather Radio... as you can not
always depend on sirens... phone calls or seeing the warnings on
Note... tomorrow... Wednesday April 22... is the tornado drill day. A
simulated watch for South Dakota will be issued at 1000 am
cdt\900 am MDT. A simulated Tornado Warning will be issued at 1015
am cdt\915 am MDT.
Severe Weather Get Mobile & Email Alerts
Big Stone Severe Watches & Warnings NOAA Weather Radio
Public Information Statement
Statement as of 6:08 am CDT on April 21, 2015