Tornado smashes small Kansas town; major tornado outbreak today

A terrible scene--played out all too often in 2007--happened again last night in Greensburg, Kansas. The sirens sounded, warning of an advancing tornado, but the black of night hid the 3/4-mile wide monster twister approaching from the southwest. The residents of this small town of 1600 had time to find safe shelter, but the tornado was so powerful, that even sturdy buildings could not protect the residents. The tornado destroyed or heavily damaged 90% of the town, destroying the central business district, city hall, and the high school. Eight people died, plus one more person 30 miles away. Damage surveys are not yet complete on the tornado, but photos I've seen of the destruction show damage consistent with EF4 winds(168-199 mph). It is possible the storm was an EF5 (winds more than 200 mph). The ten deaths yesterday bring the U.S. tornado death toll to 69 so far this year, three more than the toll for all of last year. For those interested, I've saved a 1 Mb animation of the radar reflectivity and Doppler velocities of the tornado (thanks to Wunderblogger redefined for saving these!) The animations show some very strong rotation and odd swirling behavior that I don't recall ever seeing in a tornado radar animation before.

Wunderblogger Mike Theiss was out chasing yesterday and caught some of the storms; be sure to tune into his blog over the next few days to read his chase accounts.


Figure 1. Radar image of the strom that spawned the Greensburg, KS tornado of May 4, 2007.

Major severe weather outbreak today expected
More strong (EF2 and EF3) or violent (EF4 and EF5) tornadoes are possible again tonight, and the Storm Prediction Center (SPC) has put a large area of Kansas and Nebraska under its highest risk level, "High Risk". This is the fourth time this year that SPC has issued its "High Risk" forecast. The last time it did so, on April 24, an EF3 tornado struck the Mexico/Texas border near Eagle Pass, killing ten (the "High Risk" area defined by SPC was actually a bit north of where the tornado struck). Tornadoes have already been reported in Colorado and Nebraska today, so tune into our severe weather page and radar page to follow the outbreak.

Coastal Carolina storm
The latest (8am EDT) computer forecast models continue to show a moderately strong coastal storm developing several hundred miles southeast of Cape Hatteras, North Carolina, on Monday. The storm will be extratropical in nature when it forms. It will bring strong winds and high surf to the Carolina coast for several days early next week, as it meanders offshore. Water temperatures are 22-23 C off of the coast, which may be warm enough to allow the low to acquire some subtropical characteristics and become the season's first named storm. However, none of the models are showing this, and I put the odds of a Subtropical Storm Andrea forming next week at about 10%.

Jeff Masters