Tropical Storm Warnings and Hurricane Warnings

Tropical Storm Warnings and Hurricane Warnings advise that a given coastal or inland area is expected to experience one of these storms over the next 24 hours. While these conditions are not guaranteed to occur, a warning is a strong statement that tropical storm or hurricane conditions are likely enough that everyone in an area covered by the warning should take immediate action to prepare.

A Tropical Storm Warning advises that tropical–storm force winds (sustained gales of 63–117 km/h) are expected within 24 hours. This warning could be issued for

  • a tropical storm
  • a hurricane that might approach, but only close enough to bring gales that are less than hurricane force (118 km/h or higher).

A Hurricane Warning advises that hurricane-force winds (sustained gales of 118 km/h or higher) are expected within 24 hours or less. This warning could be issued for

  • a hurricane
  • a strong tropical storm (sustained gales more than 110 km/h) that might strengthen to a hurricane before striking
  • a strong tropical storm (sustained gales more than 110 km/h) that could be accompanied by dangerously high water or a combination of dangerously high water and exceptionally high waves

Notes:

  • These warnings are not issued for marine areas.
  • Their nature as tropical storms and hurricanes also implies the threat of local flooding from heavy rainfall; therefore, warnings are not issued.
  • Hurricane warnings are issued only for tropical cyclones and not for extratropical cyclones.

Example: In November 2007 when Post-tropical Storm Noel struck the Maritimes, the entire Atlantic coast of Nova Scotia experienced wind gusts of 130–140 km/h. However, a hurricane warning was not issued because Noel had lost most of its tropical characteristics, including the eye and eyewall, prior to arrival. The regional Storm Prediction Centres did issue inland wind warnings.

See the section on Storm Preparedness.