Oregon Emergency Management - Preparedness and Disaster Blog

May 3, 2011
By Megan Taylor
Storm Tracker 9
http://kohd.com/news/local/211340



The second topic of Severe Weather Awareness Week is tornadoes and waterspouts. This topic comes during a time that a large corner of the Southeast U.S. is cleaning up from a devastating April. We'll get to that event in a moment, but first let's talk specifically about tornadoes around our area.

The Pacific Northwest sees about seven tornadoes a year. The most common months for tornadoes are July and August. However, tornadoes have been reported in every month of the year. The most common time is between 1 p.m. and 9 p.m., but they still can occur at any time.


Severe thunderstorms that produce tornadoes are a little more difficult to produce in our part of the world. That's mostly because the Pacific Ocean prevents major temperature differentials, which is one of the primary requirements for violently convective weather. However, it DOES happen. There are also a lot of hills and mountains that help keep the air moving, and can aid rotation. The worst part about Pacific Northwest tornadoes is that they are a little harder to predict and therefore harder to warn for. That means the area's citizens have to be extra prepared. Here are a few quick safety tips should a tornado occur in your area.

Come up with a tornado plan BEFORE the tornado is occurring. Waiting for a warning is too late. Designate a time ever year that you and your family put together a disaster plan. This doesn't have to be limited to just tornadoes, but it can include your earthquake or tsunami, and fire plan as well.


If faced with a tornado or your area is placed under a warning, seek shelter immediately.

If you are in a building or home:

Get away from windows and exterior walls, such as the interior-most room of the building or a closet.

Get on the lowest level of the structure. A basement is the best place during a tornado.

Get under a sturdy piece of furniture. It could block you from falling debris.


If you are in a car, buckle your seat belt and drive to a nearby sturdy structure. If debris hits your vehicle, pull over. If you can find a lower level in the road than where you are, get out and lay down with your hands over your head. YOU ARE NOT A STORM CHASER, DO NOT DRIVE TOWARD THE TORNADO. If you cannot tell which way to drive, look to see which way the tornado is heading. If it looks like it is not moving, it is likely moving straight toward you. Make a 90 degree turn and drive away quickly, but safely.


If you are in mobile home, GET OUT if time permits. Even when tied down, mobile homes lead to most of the injuries and deaths related to tornadoes. When setting up your disaster plan, make sure to pick a location to go during a tornado warning that is sturdy.


Don't wait for the sirens. Tornadoes can form and begin destroying very quickly. Just because the sirens are not sounding doesn't mean the tornado will stop and wait. If you see a tornado, take shelter immediately. Some signs of an approaching tornado include roaring sounds, large hail and falling debris. Even if you can't see the tornado, seeing debris could mean one is nearby.


Oregon and Washington average around two tornadoes a year, but as many as 14 in one year have been recorded (Washington, 1997). Recent tornadoes include a small EF-0 tornado that destroyed a barn south of Pendleton in March 2011, a likely cold-air funnel that caused damage to a house and numerous trees in Creswell in December 2010, and the Aumsville EF-2 tornado that caused tens of thousands of dollars in damage and injured two in December 2010. Waterspouts are a little more common, but due to the vastness of the Pacific Ocean, they are often not seen. In the event of a waterspout, the NWS will issue a special marine warning. Waterspouts are dangerous and cause damage boats and harbors. Waterspouts CAN move onto land, becoming what is called a "land spout."

Other parts of the country are obviously more prone to tornadoes and severe weather, but this year has been especially deadly in areas in the Southeast U.S. The area known as Dixie Alley has seen two separate major outbreaks in April, both of which left numerous people dead. Here is a quick recap of the most recent historic outbreak.

The outbreak lasted from 8 a.m. April 26 to 8 a.m. April 28. During that time, a preliminary estimate of 312 tornadoes occurred. The most active day was April 27 when 226 estimated tornadoes pummeled through parts of Dixie Alley, Texas, Oklahoma, Georgia, the Carolinas and even into the Northeast. On that day, at least 344 people were killed. While the rise in the death toll has finally decreased, given the damage, it will not likely be official until all of the rubble is sifted through. Overall, the two-day total was the most people killed since 1936 when an outbreak killed 454 people, most of which were in Mississippi and Georgia.

The deadliest tornado was the Tri-State Tornado which killed just shy of 700 people. This tornado occurred in an outbreak in March 1925 where well over 700 total fatalities occurred. Given the preliminary count for April, a few records were broken. The previous record for the most tornadoes in April was 267 which was set in 1974. The previous record for the most tornadoes recorded in any month was 542 tornadoes which was set in May 2003. Both of those records have been broken with April's preliminary 600 tornadoes this year. The record number of tornadoes in any single year is 1,817 which was set in 2004. So far, 2011 has seen 881 tornadoes with the most active month of May still occurring.


The Storm Tracker 9 Weather Team will be happy to answer any questions about tornadoes that you have.

Thank you Storm Tracker 9 Weather Team!!!