Tornadoes: The underappreciated hurricane hazard

  • Published
  • By William Roeder, 45 WS
  • 45th Space Wing
Hurricanes are well known for strong winds and heavy rain. But did you know tornadoes are also a significant threat during hurricanes? Now is the time to learn about this hazard as you prepare for hurricane season.

Some of the strongest tornadoes in Florida occur with land-falling tropical cyclones. These tornadoes can form over 250 miles from the center of the tropical cyclone. The eye of Hurricane Georges passed over Key West in 1998 and caused a tornado in Brevard County. These tornadoes form as the strong rain-bands of the tropical cyclone move on-shore or off-shore. Tornadoes also occur in the eye wall around the center of tropical cyclones.

The weather just ahead of an approaching the rain band can be deceptive. The winds may be fairly light, with no rain, and the skies may even be partly sunny. However, when the rain band moves on-shore, there is torrential rain and suddenly a tornado hits.
Don't be fooled into thinking a "mere" tropical storm isn't much of a threat because it's not a full-fledged hurricane. The land-falling rain-bands from a tropical storm can also cause tornadoes.

Tornado safety is an easy 2-step process.

STEP-1: Have A Plan. Identify the safest room in your building and ensure everyone knows it. This includes your work center and your home. The safest rooms are on the lowest floor, away from windows, farther inside, and smaller rooms with solid construction like restrooms and closets. Basements are even safer. A strong table and/or thick pads can protect you against falling debris. Motorcycle and sports helmets can reduce head injuries. People in mobile homes or other weak portable buildings should seek proper shelter elsewhere. A common myth is to open windows to let the building "breathe". Houses do not explode from decompression in a tornado. Opening a window actually increases the danger.

Step-2: Keep Informed. The 45th Weather Squadron (45 WS) gives the potential for tornadoes and other severe weather at KSC/CCAFS in their daily 24-Hour and Weekly Planning Forecasts (www.patrick.af.mil). If the threat continues, 45 WS then issues a severe weather watch with a desired lead-time of 4 hours. Finally, if tornadoes are imminent or observed, 45 WS issues a tornado warning with a desired lead-time of 5 minutes. Follow adverse weather local procedures.

At home, stay informed about approaching severe weather. The National Weather Service in Melbourne gives the potential for severe weather in their general forecasts, issues a tornado watch when conditions are expected that may produce tornadoes, and issues a tornado warning when one has been detected (www.srh.noaa.gov/mlb). If severe weather is likely, review your safety plan, including your family, especially reminding everyone of the safest room. Store any loose outside materials and close protective shutters if there is time before the high winds start. If a tornado or severe weather watch is issued, listen for weather warnings and be ready to act. If a tornado warning is issued for your area, go your safe room immediately. Go to your safe room if threatening weather approaches even if an official warning was not issued - there may not be time for that warning.

One of the best aids to weather safety is 'NOAA All Hazards Radio', formerly known as 'NOAA Weather Radio' (www.weather.gov/nwr). Tornadoes from tropical cyclones happen at any time of the day or night. Late night tornadoes are especially dangerous since people are asleep and don't see weather warnings on TV. However, NOAA Radio will sound a loud alarm if the National Weather Service issues a weather warning for your area. This is essential if you live in a location without a tornado siren. Even if you live near a siren, it may not be loud enough to wake you inside your house. 'NOAA Radio' provides alternatives for the hearing and visually impaired. NOAA Radio doesn't cover 2% of the country, so test the reception of new radios to be sure you're covered.

A back-up way to receive severe weather warnings is also a good idea. A cell phone with text messaging/e-mail by your bed is especially good. That way you'll have the cell phone in-hand in case of emergency. Some county emergency management offices and all the Orlando TV station websites offer free severe weather warning text/e-mail service (though your cell phone plan might charge for receiving these messages). Some companies also offer this service for a small annual fee. You can even set different ring tones for those calls, e.g. a loud alarm. Some of these services allow targeting of the messages to specific locations so that you are notified only of warnings that affect you. The National Weather Service is expanding their text message/e-mail warnings to the general public during 2010-2011.

Weather safety training is available from 45th Weather Squadron 45wscc@patrick.af.mil, 494-7426.