Saturday, April 16, 2011

At Least Four Confirmed Tornadoes In Virginia On Saturday

Severe thunderstorms raced across the area Saturday afternoon and produced widespread damage. At one point, storms were moving 55 to 70 mph. There are now at least four confirmed tornadoes in Virginia.

One tornado touched down in Augusta County (EF-1 with max winds 95 mph) and knocked down several trees and destroyed numerous barns.

A tornado is now confirmed in Dinwiddie County with a path around 8 miles long and 300 yards wide. Many homes were damaged along the path of this tornado.

Two more tornadoes were confirmed in Isle Of Wight and Gloucester counties. There was extensive damage in Gloucester with three fatalities. National Weather Service is going to survey the damage more today to see the strength of the tornado.

There was also wind damage in Halifax County where eight homes were destroyed with four minor injuries. National Weather Service will survey the damage today to see if this was from a tornado.

At one point, the Tri-Cities area was under a Tornado Warning, however, with the exception to a few toppled tress, there were no reports of major damage.

There were a few reports of hail in Crewe and Powhatan. We received pictures of quarter to golfball-sized hail.

Here are some maps which show all of the storm reports from today. The "W" represents wind damage, "H" is hail and "T" is tornado. North Carolina was hit hardest today, where there were nearly 100 tornado reports!

Sunday, April 10, 2011

What I'm Watching Heading Into Hurricane Season

Colorado State came out with their forecast for the upcoming hurricane season. They are calling for an above average season with 16 named storms, 9 hurricanes and 5 major hurricanes. Here are a few things we will be watching over the next couple months leading to the start of hurricane season.

La Nina

Hurricanes like warm ocean water and low wind shear. Wind shear is typically low during La Nina, which would lead to an active season. However, La Nina is rapidly weakening (see the map below), so the forecast isn't as clear-cut.

Atlantic Water Temperatures

As I stated above, hurricanes strive in warm ocean water. Sea surface temperatures (SST) have been above normal over the past few months, which points towards an active season.


The North Atlantic Oscillation (NAO) has an impact on the Trade Winds. We saw a dramatic shift to a positive NAO during January. This increased the Trade Winds and has consequently cooled the Atlantic waters slightly. If we remain in a positive phase, then ocean temperatures could continue to cool.


Colorado State has already decreased it's initial forecast for this upcoming hurricane season. If La Nina continues to weaken and NAO remains mostly positive, then we might see the number of named storms and hurricanes decrease. We will continue to track this and bring you more updates.