1. Education

Billion Dollar Weather Events of 2012

By

No other year in recent history has stirred talk of doom and disaster quite like 2012.

That year has now come and gone. And while the world didn't end, one part of its predictions did prove true--an increased number of extreme weather events were seen around the world, especially in the United States.

1. Tornado Outbreak (Ohio Valley, Southeast)

Occurrence: March 2-3, 2012
Estimated cost: $4 billion

At the start of the month, a powerful low pressure system tracked across the Midwest and Southeast, triggering a round of severe weather in the pre-dawn hours of March 2. Two things added to the extreme nature of this event. For one, the above-average temperatures that had been in place across the nation during February still lingered and gave air at surface levels added instability. (Several cities set new high temperature records for March 2, including Bowling Green, KY (82°F) and Paducah, KY (80°F)). Another factor was the strong, 150+ mph jet stream winds in the upper atmosphere. Not only did this make for fast-moving storms, it also aided tornado formation by contributing a strong twisting motion to thunderstorm updrafts.

Overall, a total of 75 tornado reports were confirmed across eleven states, making this the largest tornado outbreak on record for the month of March. (The previous record count was 74 occurring on March 11-13, 2006). Having caused 42 fatalities, it is also the second deadliest March outbreak.

2. Tornado Outbreak (Texas)

Occurrence: April 2-3, 2012
Estimated Cost: $1.3 billion

On the morning of April 3, a low tracked across the Southern Plains, bringing severe thunderstorms to north Texas. As the morning wore on, the storms grew more destructive as a gust front from a line of storms in Oklahoma merged with the system. This providing additional uplift and ultimately triggering the growth of supercells near the I-20 corridor.

A total of 22 tornadoes were confirmed, including three in the Dallas Fort Worth metro area--an EF2 in Arlington, EF2 in Lancaster, and an EF3 in Forney. Over one thousand homes were damaged.

Despite hitting this heavily populated city, only a few injuries, and no fatalities were reported.

3. Tornado Outbreak (Midwest)

Occurrence: April 14-15, 2012
Estimated Cost: $1.75 billion

For the first two weeks in April, sea surface temperatures in the Gulf of Mexico measured 1.5°C above average--the warmest they've been in any April on record. It was the explosive combination of this unusually warm moist air feeding into a passing storm system that led the Storm Prediction Center to issue a "High Risk" forecast (the highest level of storminess alert) more than a day in advance of storm development.

By the end of the event, the confirmed tornado count across Texas, Oklahoma, Kansas, and Nebraska had reached 98. The most violent of these was an EF4 that touched down in Ellsworth County, KS. Six fatalities were reported in Woodworth, OK, where an EF3 tornado struck without warning when lightning caused the town's tornado warning system to fail.

4. Severe Weather (Midwest, Ohio Valley)

Occurrence: April 27-May 1, 2012
Estimated Cost: $4 billion

On the one-year anniversary of the April 2011 Super Tornado Outbreak (the largest and most damaging severe weather outbreak in world history), severe weather broke out across the states of Texas, Oklahoma, Kansas, Missouri, Illinois, Indiana, and Kentucky. While several tornadoes touched down, it was hail that caused a considerable amount of damage. One fatality was reported.

5. Severe Weather (Southern Plains, Ohio Valley, Northeast)

Occurrence: May 25-30, 2012
Estimated Cost: $2.5 billion

A strong cold front swept across the southern Plains, spawning 27 tornadoes in the Midwest and Northeast. Severe damage from hail and straight-line winds resulted, as well as one fatality.

6. Severe Weather (Rockies, Southwest)

Occurrence: June 6-12, 2012
Estimated Cost: $1.75 billion

Several days of severe storms during what turned out to be the hottest June on record for the Denver area, was enough to spawn 25 tornadoes along the Rocky Mountains. The state of Colorado alone withstood nearly $1 billion dollars in hail damage.

7. Severe Weather (Midwest, Appalachians, Mid-Atlantic)

Occurrence: June 29-July 2, 2012
Estimated Cost: $3.75 billion

Do you remember the storm with the strange name that hit the DC area last summer? This derecho, or fast-moving complex of severe thunderstorms, traveled a length of 800 miles in less than 48 hours. The storm's winds, which included gusts of over 90 mph (that's comparable to hurricane-force), left over 3 million residents without power. By the end of the event, 28 lives had been claimed.

Derechoes are considered violent storms, but this one was exceptionally so due to the build up of extreme heat in the atmosphere from the summer heatwave. This extraneous heat helped fuel the derecho's thunderstorms by increasing instability.

It is considered one of the worst such storms on record.

8. Hurricane Isaac

Occurrence: August 2012
Estimated Cost: $2 billion

9. Hurricane Sandy

Occurrence: October 2012
Estimated Cost: $62 billion

10. Wildfires (Western U.S.)

Occurrence: Summer-Fall 2012
Estimated Cost: ? billion

With over 9.2 million acres of land burned in this year's U.S. wildfires, the 2012 fire season now ranks as the third worst in United States history. (2006 and 2007 are the largest, respectively.)

New Mexico's Whitewater/Baldy wildfire (started by lightning) was the largest in state history, while the Waldo Canyon wildfire (which was human-caused) was that state's most destructive ever. Its flames engulfed and destroyed several hundred homes near Colorado Springs, CO.

The fires claimed 8 lives.

11. U.S. Drought & Heatwave

Occurrence: January-December 2012
Estimated Cost: $35 billion

The 2012 drought is considered the most extensive drought to affect the Unites States since the 1930s Dust Bowl era. Extreme drought conditions have affected more than half of the U.S., with the hardest hit areas including America's heartland and agriculture states. The heatwave experienced over the summer of 2012 (July was the hottest of any month in U.S. history) only acted to worsen the unyielding drought.

Over 130 fatalities are associated with both events. That number may continue to increase as the drought conditions linger into 2013.

How does 2012 rank among other years?

On average, the U.S. experiences 3 or 4 billion-dollar weather disasters a year. Of that number, 1 or 2 may be tornado, or severe weather related. Having a total of 11 events, 7 of which were severe weather related, 2012 surpassed both of these figures. In fact, only 2011 had a higher billion-dollar events count--14.

Counting events gives an idea of how frequently the nation was plagued with dangerous weather, but it doesn't paint a complete picture about how much of the U.S. was impacted by it. For this, climatologists use what's known as the U.S. Climate Extremes Index. According to this index, 2012 is considered the second most extreme year on record for the United States (1998 ranks as the most extreme year).

©2014 About.com. All rights reserved.