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Answer: According to a climatology of severe weather for central NC produced by our local NWS office, the Raleigh county warning area (covering 31 counties) averages about 5 tornadoes per year. Comparing tornado rates for different parts of the country requires balancing the area involved in the estimates, and a few different methods have been applied in various studies and technical reports. For example, a method estimating the number of tornadoes occurring within 25 nautical miles of any given point shows a value of .4-.8 per year for central NC versus about 1.0-1.4 per year over central OK in the heart of "tornado alley." A similar statistic for F2 and stronger tornadoes shows about 5-15 per century for our state versus about 35-40 there. Another estimate of the fraction of land surface disturbed by tornadoes each year in NC is about 2.1 x 10^-4, compared to around 4.4 to 4.8 x 10^-4 in the most active regions of the country. Finally, an analysis of tornadoes from 1950-2003 that counted tornado events within 2-degree latitude by 2-deg longitude boxes across the U.S. showed 303 in a box including our area, while boxes in the central plains states ranged from around 700 to as high as 942. Taken all together, then, we see that the "tornado alley" areas have about 2-3 times as many tornadoes over a given area as we do overall, but if you exclude the weak F0 and F1 tornadoes and look in particular at the more powerful F2 intensity and higher storms, those are about 4-5 times more likely in states like Oklahoma than they are around here.
Oct. 29, 2009 | Tags: normals, severe weather, tornadoes

Answer: You probably noted in the class that most significant tornadoes form on the right rear flank of supercell thunderstorms, relative to the direction of storm movement. If the supercell is a "discrete" storm, out on its own, then most of the rain, thunder and lightning would be over when the tornado moves through or very shortly afterward. However, sometimes the tornadic supercell can be just one part of a larger group or line of thunderstorms, in which case additional areas of rain, lightning and perhaps hail may pass across the same area. In rare cases, there can even be multiple tornadic cells that cross the same or nearly the same location.
Sep. 17, 2009 | Tags: severe weather, thunderstorms, tornadoes

Answer: A check of local storm reports compiled by NOAA's Storm Prediction Center for that date, along with local news stories, shows that straight-line winds associated with a severe thunderstorm was the most likely reason for a number of trees that were toppled in the vicinity of Red Mountain Road around 2 pm. There were two tornado reports in the state that day, near Pinetown and Washington, both in Beaufort County. You can see storm reports for that day at www.spc.noaa.gov/climo/reports/090717_rpts.html, and can also scroll to the bottom of the page to select another date.
Aug. 7, 2009 | Tags: cool sites, past weather, severe weather, tornadoes

Answer: The WeatherCall program places an automated telephone call to subscribers whenever their address falls within the bounds of severe thunderstorm warnings and tornado warnings issued by the National Weather Service. The best way to sign up is through our web site. You can access the sign-up page by clicking the "WeatherCall" link near the top of most weather pages on our site, or by going directly to www.wral.com/weather/page/3567856/.
Jul. 22, 2009 | Tags: preparedness, severe weather

Answer: There are a few states that have had very little tornadic activity, notably Hawaii and Alaska, while other states like Florida, Oklahoma, Indiana, Iowa and Kansas lead the nation in numbers of tornadoes per 10,000 square miles. However, there is no state in the union that has never experienced at least a few tornadoes.
Jul. 3, 2009 | Tags: records/extremes, severe weather, tornadoes

Answer: That is correct. The person who coined the term derecho for a widespread convectively-induced damaging wind event based the name on the Spanish word for "direct" or "straight ahead" since most of the wind damage in a derecho is usually due to straight-line downburst winds. This is in contrast to a possible origin for the word tornado, which may be based on the Spanish word "tornar," which means "to turn." This background information on the term derecho is included as part of an extensive description of the phenomenon at www.spc.noaa.gov/misc/AbtDerechos/derechofacts.htm.
Jun. 1, 2009 | Tags: severe weather, winds

Answer: A supercell is a particular type of thunderstorm characterized by a long lifetime and an organized, rotating updraft area called a mesocyclone. A severe thunderstorm is defined as one that produces wind gusts to 58 mph or higher, hail three-quarters of an inch in diameter or greater, or a tornado. Many severe storms are supercells, but other kinds of thunderstorms can become severe as well.
Jun. 3, 2009 | Tags: hail, severe weather, thunderstorms, tornadoes, winds

Answer: One path you could follow is to select meteorology as a college major and pursue a career in the field, or you could join the military as a weather specialist. Some less formal options include taking a severe weather training class from the National Weather Service and serving as a SkyWarn spotter, or attending meetings of the nearest American Meteorological Society chapter.
Apr. 17, 2009 | Tags: severe weather

Answer: In mid-latitude locations like North Carolina, March is a transition period between winter and spring, with both a lingering potential for wintry weather with strong cold outbreaks, and early intrusions of warm, unstable air that can interact with frontal systems and the jet stream to produce severe thunderstorms. At RDU, we have had temperatures in March ranging from 11 to 92!
Mar. 16, 2009 | Tags: severe weather, thunderstorms

Answer: The primary formal groups that would seem to fit that description would probably be the Central North Carolina Chapter of the American Meteorological Society, which welcomes meteorologists and other interested individuals (www.nc-climate.ncsu.edu/ams/) and Central Carolina Skywarn, a group of trained volunteer severe weather spotters with a web page at www.centralcarolinaskywarn.net/.
Mar. 15, 2009 | Tags: severe weather