Emergency Plan - Grand Strand Water and Sewer Authority

EVENT SPECIFIC GUIDELINES 2 (ESG-2)
TORNADO
3.2.2. The FUJITA SCALE of TORNADO INTENSITY
Tornado Wind
F-Scale
Intensity Speed Types of Damage
Number
Phrase (MPH)
F0 Gale 40 – 72
F1 Moderate 73 – 112
F2 Significant 113 – 157
F3 Severe 158 – 206
F4 Devastating 207 – 260
F5 Incredible 261 – 318
F6 Inconceivable 319 - 379
3.2.3. THREAT or HAZARD INFORMATION
Some damage to chimneys; breaks branches off
trees; pushes over shallow-rooted trees; damages
signboards.
Reaching hurricane wind speeds; peels surface off
roofs; mobile homes pushed off foundations or
overturned; moving vehicles pushed off the road;
attached garages may be destroyed.
Considerable damage. Roofs torn off frame
houses; mobile homes demolished; boxcars pushed
over; large trees snapped or uprooted; light object
missiles generated.
Roof and some walls torn off well-constructed
houses; trains overturned; most trees uprooted.
Well-constructed houses leveled; structures with
weak foundations blown off some distance; cars
thrown and large missiles generated.
Strong frame houses lifted off foundations and
carried considerable distances to disintegrate;
automobile sized missiles fly through the air in
excess of 100 yards; trees debarked; steel
reinforced concrete structures badly damaged.
These winds are very unlikely, but would result in
total destruction.
Tornado: A funnel-shaped, rotating column of air, extending from a cloud
base to the ground. Wind speeds can range from 40 mph to over 250 mph.
Tornado Watch: Issued by the National Weather Service when conditions
are favorable for the formation of tornadoes. Indicates a tornadoe could
form.
Tornado Warning: Issued by the National Weather Service when a tornado
has actually been sighted or is indicated by weather radar. Indicates a
tornado has formed.
Waterspout: A funnel-shaped, rotating column of air, extending from a
cloud base to a body of water such as the ocean or a large lake. In this
region they are typically fairly weak, but they can reach F0 or F1 tornado
Grand Strand Water & Sewer Authority 101 CONFIDENTIAL MATERIALS
Emergency Management Plan
SECURITY SENSITIVE
June 7, 2013
NOT FOR PUBLIC
DISCLOSURE