A Severe Thunderstorm Warning remains in effect until 10:30 pm EDT for Barnstable County. At 9:44 pm EDT, Doppler radar indicated a cluster of severe thunderstorms across the Western Cape capable of producing damaging winds in excess of 60 mph moving east across the Cape at 30 mph. In addition, within the last 10 minutes, numerous locations across the Western Cape have reported wind gusts of around 55 to 65 mph including West Falmouth, Otis airforce base, and Woods Hole. Locations impacted include: Barnstable, Falmouth, Brewster, Yarmouth, Sandwich, Bourne. Dennis, Mashpee, Harwich, Chatham, Orleans, Eastham, Wellfleet and Hyannis.
A Tornado Watch remains in effect for the warned area. Although not immediately likely, if a tornado is spotted, move to a place of safety such as a basement or small interior room.
- To begin preparing, you should build an emergency kit and make a family communications plan.
- Remember the 30/30 Lightning Safety Rule: Go indoors if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay indoors for 30 minutes after hearing the last clap of thunder.
- Secure outdoor objects that could blow away or cause damage.
- Get inside a home, building, or hard top automobile (not a convertible). Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside.
- Shutter windows and secure outside doors. If shutters are not available, close window blinds, shades or curtains.
- More about what to do before thunderstorm and lightning.
- Avoid contact with corded phones and devices including those plugged into electric for recharging. Cordless and wireless phones not connected to wall outlets are OK to use.
- Avoid contact with electrical equipment or cords. Unplug appliances and other electrical items such as computers and turn off air conditioners. Power surges from lightning can cause serious damage.
- Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry. Plumbing and bathroom fixtures can conduct electricity.
- Stay away from windows and doors, and stay off porches.
- If you are driving, try to safely exit the roadway and park. Stay in the vehicle and turn on the emergency flashers until the heavy rain ends. Avoid touching metal or other surfaces that conduct electricity in and outside the vehicle.
- More about what to do during thunderstorm and lightning.
What is a Severe Thunderstorm Warning?
This is issued when either a severe thunderstorm is indicated by the WSR-88D radar or a spotter reports a thunderstorm producing hail one inch or larger in diameter and/or winds equal or exceed 58 miles an hour; therefore, people in the affected area should seek safe shelter immediately. Severe thunderstorms can produce tornadoes with little or no advance warning. Lightning frequency is not a criteria for issuing a severe thunderstorm warning. They are usually issued for a duration of one hour. They can be issued without a Severe Thunderstorm Watch being already in effect.
Like a Tornado Warning, the Severe Thunderstorm Warning is issued by your National Weather Service Forecast Office (NWFO). Severe Thunderstorm Warnings will include where the storm was located, what towns will be affected by the severe thunderstorm, and the primary threat associated with the severe thunderstorm warning. If the severe thunderstorm will affect the nearshore or coastal waters, it will be issued as the combined product–Severe Thunderstorm Warning and Special Marine Warning. If the severe thunderstorm is also causing torrential rains, this warning may also be combined with a Flash Flood Warning. If there is an ampersand (&) symbol at the bottom of the warning, it indicates that the warning was issued as a result of a severe weather report.
After it has been issued, the affected NWFO will follow it up periodically with Severe Weather Statements. These statements will contain updated information on the severe thunderstorm and they will also let the public know when the warning is no longer in effect.