<P> There are four types of derechos: </P> <Ul> <Li> Serial derecho--This type of derecho is usually associated with a very deep low . <Ul> <Li> Single - bow--A very large bow echo around or upwards of 250 miles (400 km) long . This type of serial derecho is less common than the multi-bow kind . An example of a single - bow serial derecho is the derecho that occurred in association with the October 2010 North American storm complex . </Li> <Li> Multi-bow--Multiple bow derechos are embedded in a large squall line typically around 250 miles (400 km) long . One example of a multi-bow serial derecho is a derecho that occurred during the 1993 Storm of the Century in Florida . Because of embedded supercells, tornadoes can spin out of these types of derechos . This is a much more common type of serial derecho than the single - bow kind . Multi-bow serial derechos can be associated with line echo wave patterns on weather radar . </Li> </Ul> </Li> <Li> Progressive derecho--A line of thunderstorms take the bow - shape and may travel for hundreds of miles along stationary fronts . Examples of this include "Hurricane Elvis" in 2003 and the Boundary Waters - Canadian Derecho of 4--5 July 1999 . Tornado formation is less common in a progressive than serial type . </Li> <Li> Hybrid derecho--A derecho with characteristics of both a serial and progressive derecho . Similar to serial derechos and progressive derechos, these types of derechos are associated with a deep low, but are relatively small in size . An example is the Late - May 1998 tornado outbreak and derecho that moved through the central Northern Plains and the Southern Great Lakes on 30--31 May 1998 . </Li> <Li> Low dewpoint derecho--A derecho that occurs in an environment of comparatively limited low - level moisture, with appreciable moisture confined to the mid-levels of the atmosphere . Such derechos most often occur between late fall and early spring in association with strong low pressure systems . Low dewpoint derechos are essentially organized bands of successive, dry downbursts . The Utah - Wyoming derecho of 31 May 1994 was an event of this type . It produced a 105 mph wind gust at Provo, Utah, where sixteen people were injured, and removed part of the roof of the Saltair Pavilion on the Great Salt Lake . Surface dewpoints along the path of the derecho were in the mid-40s ° F . </Li> </Ul> <Li> Serial derecho--This type of derecho is usually associated with a very deep low . <Ul> <Li> Single - bow--A very large bow echo around or upwards of 250 miles (400 km) long . This type of serial derecho is less common than the multi-bow kind . An example of a single - bow serial derecho is the derecho that occurred in association with the October 2010 North American storm complex . </Li> <Li> Multi-bow--Multiple bow derechos are embedded in a large squall line typically around 250 miles (400 km) long . One example of a multi-bow serial derecho is a derecho that occurred during the 1993 Storm of the Century in Florida . Because of embedded supercells, tornadoes can spin out of these types of derechos . This is a much more common type of serial derecho than the single - bow kind . Multi-bow serial derechos can be associated with line echo wave patterns on weather radar . </Li> </Ul> </Li> <Ul> <Li> Single - bow--A very large bow echo around or upwards of 250 miles (400 km) long . This type of serial derecho is less common than the multi-bow kind . An example of a single - bow serial derecho is the derecho that occurred in association with the October 2010 North American storm complex . </Li> <Li> Multi-bow--Multiple bow derechos are embedded in a large squall line typically around 250 miles (400 km) long . One example of a multi-bow serial derecho is a derecho that occurred during the 1993 Storm of the Century in Florida . Because of embedded supercells, tornadoes can spin out of these types of derechos . This is a much more common type of serial derecho than the single - bow kind . Multi-bow serial derechos can be associated with line echo wave patterns on weather radar . </Li> </Ul>

What are winds specific to an area or region called