National Weather Service United States Department of Commerce

Arctic Blast Set to Arrive on Thanksgiving; Dangerous Wind Chills, Lake Effect Snow, Severe Thunderstorms

A significant arctic outbreak will arrive in the northern Rockies and northern Plains on Thanksgiving into Friday and advance farther south and east through much of the Plains and Midwest this weekend. Dangerous wind chill temperatures are expected with a significant long duration lake effect snow event possible downwind of the Great Lakes. Severe thunderstorms may be possible in the Southeast. Read More >

  • Tornado Sighted/Confirmed Warning

Biggest takeaway:
This is a rare event, but one that needs to be planned for given its catastrophic potential. Any plan will likely revolve around near instant notification of all people with a canned, prepared statement of what can be done to take cover very quickly.  This plan should be able to link to your Tornado Warning plan (the "threat" listed just above this one) to enhance actions (hopefully) already taken from the NWS tornado warning that likely was already issued.

Warning/Trigger for Plan:
Either:
A)  NWS Tornado Warning mentioning “CONFIRMED” tornado.
B)  Sighted tornado from your location

Advance Notice/Time to Activate & Accomplish Your Planned Response:
Plan on 0-2 minutes of advance warning
Allow options that there may be as much as 10 mins if a NWS Tornado Warning contains confirmation of a tornado [uncommon].

Frequency:
Rare, but a high end threat that needs to have a plan to allow proper response.

How Accurate Warnings?
If a tornado is confirmed in a warning, or you see one - the threat is there. It will just be a matter of if it will hit your exact location. Race to do what you can.

 

  • Note:  Any NWS Tornado Warning for your location will quickly activate the Wireless Emergency Alert system and will alert the cell phones of most of the people in your location. Their message will be generic and only say "Tornado Warning in your area until xx:xx [time]". That short message will likely impact their response and awareness, and needs to be taken into account in your planning.
  • Tornado winds could be just enough to cause downed trees & stripping off siding and shingles (>60 mph) [more common], or enough to cause catastrophic, structural damage (>120 mph) [rare]. However, it typically isn't known how strong the winds are while the storm is ongoing. Therefore, the best action is to treat all tornado threats the same - as a potential catastrophic threat.
  • Often the wind is not the direct threat - what is carried in the wind is. Consider that you may be able to stand against a 60 mph wind, but that wind may be carrying a 2x4, glass, or more.
  • Safest situation:
    • In a sturdy, enclosed structure – not a mobile home
      • Away from windows
      • Be as low as possible in the structure
        • Winds increase with height
        • If a tree falls into your structure, the upper levels will be most damaged
      • Put as much structure between you and the outside as possible
        • Homes: Typically the lowest level, interior room.
        • Buildings: Typically interior hallways or concrete staircases.
  • Safety References: