(NOAA Storm Prediction Center)

If the final three-day tornado count comes out to more than 163 storms, this would exceed the average number of twisters observed during an average April! Weather.com estimates the total is 153 after accounting for duplicate reports but an official final count is still to be determined.

(Video shot from a truck near Wilson, N.C., as a tornado demolishes a Walgreens store Saturday. This video features what I believe to be the calmest tornado damage narration in Youtube history. Note that this person was far too close to the tornado for comfort, and should’ve been driving away from the storm, not parked in its path).

AccuWeather’s severe weather expert, Henry Margusity, put it this way: “There has not been a tornado outbreak in history over three days with this many tornadoes spawned by a single storm system [emphasis added] .”

Fortunately, the event spared the Washington area of its worst impacts, although tornado warnings were issued for several suburban counties.

The hardest hit states included North Carolina, Alabama, Georgia, Mississippi and Virginia. In North Carolina, Sunday may go down as the most active day of severe thunderstorms in that state’s history, beating out an outbreak in 1984, when 22 tornadoes killed 57 people, including 15 people in South Carolina. The lower death toll this time is undoubtedly due in part to improved forecasts as well as technologies that enable warnings to be spread almost instantly to large numbers of people.

Tornado warnings issued Saturday in North Carolina, South Carolina, and Virginia in red. Severe thunderstorm warnings in yellow; flood warnings in green.

Unlike major outbreaks in the past, including the “Super Outbreak” of 1974, considered a benchmark event in American tornado history, this one was broadcast by national TV stations such as The Weather Channel and CNN, as well as via social networks like Twitter, whose 140-character limit makes it an ideal medium for broadcasting urgent weather warnings.

Streaming videos were available from storm chasers as the event unfolded, with tornado videos proliferating on Youtube throughout the event as well. Damage photos submitted via services like Instagram allowed TV meteorologists to confirm tornado touchdowns within minutes of their occurrence.

Also, once again, the outbreak highlighted the inaccuracy of the conventional wisdom that tornadoes do not strike cities. Two metropolitan areas - Jackson, Miss., and Raleigh, N.C., - were hit with EF-3 tornadoes. Stunned residents, storm chasers and surveillance cameras all provided witness to the destruction. The livecam video below from Raleigh TV station WRAL showing a twister slicing its way past one of the tallest buildings in the city should help put this myth to rest.

(Webcam image of tornado approach Raleigh. On YouTube, it is described as a wedge tornado; but it’s not clear that’s the case--as everything you see bearing down on Raleigh is not just the tornado but also dark clouds and rain. The tornado itself is most likely obscured or “rain-wrapped”).

Tragically, the Raleigh tornado killed five people, including three children in one mobile home.

Radar image as the tornado approaches Raleigh. Notice the hook shape of the red shade around Raleigh, often indicative of a tornado. You can also see a dark splotch or ball immediately above the text Raleigh. That is likely indicative of the tornado’s debris field. (Brad Panovich, WCNC)

The storm also proved that National Weather Service forecast offices are not immune to severe weather, as employees at the local forecast office in Raleigh were forced to take shelter at one point as a tornado passed nearby (meteorologists passed official warning responsibilities to another office in North Carolina).

While no major outbreak of severe weather is expected today, tornado season has only just begun.


Carolina tornado outbreak, 4/16/2011 (excellent technical recap)

US tornadoes killed 45; watch storm videos

Tornadoes “Unpredictable”? Hardly.