Sunday, February 26, 2012

Weather Resource: EF-Scale of Tornado Damage Intensity

With the spring severe weather season fast approaching, I thought it would be a good time to review some related material over the coming days and weeks. This post on the Enhanced Fujita Scale of Tornado Intensity was originally made in August of 2010:


The Enhanced Fujita (EF) Scale rates the strength of tornadoes in the U.S. based on the character and intensity of damage that they cause to existing structures.

In 1971, tornado pioneer Ted Fujita developed the F-Scale (or Fujita Scale) of tornado intensity.  While the new EF-Scale operates on the same basic premise   as the original F-Scale, it was revised to better reflect the results of tornado damage surveys.  The EF Scale attempts to align tornado wind speed estimates more closely with observed structural damage on the ground.  The EF-Scale was officially launched for use in February of 2007.

The EF-Scale chart below was adopted from the Wikipedia article on the subject, found here.


ScaleWind speedRelative frequencyPotential damage
mphkm/h
EF065–85105–13753.5%Minor damage.
Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over.
Confirmed tornadoes with no reported damage (i.e., those that remain in open fields) are always rated EF0.
EF1
86–110138–17831.6%Moderate damage.
Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken.
EF2111–135179–21810.7%Considerable damage.
Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.
EF3136–165219–2663.4%Severe damage.
Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance.
EF4166–200267–3220.7%Extreme damage to near-total destruction.
Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated.
EF5>200>322<0.1%Total destruction.
Strong frame houses leveled off foundations and swept away; steel-reinforced concrete structure badly damaged; high-rise buildings have significant structural deformation.


Below are some photos that give examples of the above EF intensities:


Examples of EF-0 Damage:





Examples of EF-1 Damage:




Examples of EF-2 Damage:




Examples of EF-3 Damage:




Examples of EF-4 Damage:




Examples of EF-5 Damage:




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1 comment:

Anonymous said...

Thank you for this site. My son is using the information for his Science Fair project on tornadoes.