Review of the Most Extreme U.S. Weather Events of 2012

Extreme weather is helping Americans to accept the veracity of climate science. Thousands were killed due to extreme weather in the U.S. in 2012 and the costs amount to hundreds of billions of dollars in property damage, diminished agricultural yields and lost productivity. In 2012, there were eleven extreme weather events in the U.S. which cost a billion dollars or more. With the exception of 2011, when there were fourteen such disasters, 2012 saw more extreme weather events than in any year in U.S. history.

Extreme weather is a serious problem and it will become much more serious if we continue with business as usual. At the opening of COP 18, the annual United Nations climate summit in Doha, Qatar, UN climate chief Christina Figueres, urged governments around the world to “do something about” extreme weather. “We have had severe climate and weather events all over the world and everyone is beginning to understand that is exactly the future we are going to be looking about if they don’t do something about it.”

A review by Jeff Masters indicates that there were numerous examples of anomalous U.S. Weather phenomenon in 2012, here is a summary of the most severe extreme events.

Hurricanes

Hurricane Sandy slammed into the U.S. eastern seaboard in late October 2012. It left 8.5 million customers without power, killed more than 130 people and costing between 60 and 80 billion dollars. Stretching from Florida to Nova Scotia, Hurricane Sandy is the largest hurricane on record. The storm struck with a force equivalent to five Hiroshima-sized atomic bombs and impacted one-fifth the area of the contiguous U.S. In total, the storms covered 1.4 million square miles—nearly one-half the area of the contiguous U.S. In addition to hurricane force winds, the storm created twelve-foot high seas that caused widespread flooding. Sandy also generated blizzard conditions for the central and southern Appalachians shattering October snow records dumping more than a foot of snow in six states from North Carolina to Pennsylvania.

Hurricane Isaac struck near the mouth of the Mississippi River on August 28th and caused $2 billion in damage. Although nowhere near as devastating as Hurricane Sandy, it was nonetheless a Category 1 Hurricane with 80 mph winds. Isaac caused a storm surge of up to eleven feet and torrential rainfall of more than twenty inches observed in some areas of New Orleans. Most notably, Isaac disrupted the 2012 Republican Convention in Tampa.

Heat Drought and Wildfires

By the end of the Summer of 2012, nearly two-thirds of the U.S. was suffering from moderate to extreme drought. Like Hurricane Sandy, this drought was a tangible reminder of human induced climate change. The months of March and July as well as the annual temperature were all warmest on record in the contiguous U.S.

The scorching heat was equalled by the absence of precipitation inducing what is now called the Great U.S. Drought of 2012. The drought impacted the production of corn, soybean and livestock. Crop damages alone from the great drought are estimated at $35 billion and this number is expected to increase as the full costs are factored.

The heat and drought in 2012 also produced the third worst U.S. fire season ever. A total of 9.2 million acres were burned.

Tornadoes

On March 2 – 3 a deadly tornado outbreak swept through the nation’s midsection and killed 41 people. A total of 70 tornadoes touched down in eleven states including two EF-4 tornadoes. Total damage was estimated at $4 billion.

A severe weather outbreak in the Ohio Valley April 30 – May 1 caused 38 tornadoes and $4 billion in damage. A strong cold front moving through the U.S. on May 25 – 30 spawned 27 tornadoes from Texas to the Northeast. Damage was estimated at $2.5 billion, much of it from hail.
A tornado outbreak on April 13 – 14 in the Plains spawned 98 tornadoes and caused at least 6 fatalities. Damage was estimated at $1.75 billion.

Several days of severe storms across the Southwest spawned 25 tornadoes from June 6 – 12. Significant hail damage occurred across the Rocky Mountain Front Range, with total damage estimated at $1.75 billion.
On March 9 a rare tornado hit the towns of Lanikai and Kailua on Oahu in Hawaii. Another extreme weather anomaly took place on July 30 along the slope of Mount Evans where a high elevation tornado was observed at 11,900 feet which is the second highest observed tornado in the U.S.

Storms

In 2012, extreme heat spawned a number of powerful storms in the U.S. On June 29th a violent line of severe thunderstorms swept across the U.S. from Illinois to Virginia. At least 38 of these thunderstorms generated wind gusts in excess of hurricane force. These storms killed 22 people and caused $3.75 billion worth of damages leaving 3.4 million people without power.

Early in June, heavy rains from Tropical Storm Debby caused damage estimated at $310 million. On June 20, thunderstorms caused record flooding in and around Duluth Minnesota with over 8 inches of rainfall observed in 24 hours in parts of the city. Two rivers in the Duluth area, the Nemadji and St. Louis, reported their highest flood heights on record. Damage was estimated at $175 million.
A massive winter storm impacted the Pacific Northwest on January 18 – 23. Huge amounts of rain and snow fell, and hurricane-force wind gusts knocked out power to 250,000 customers. Damage was estimated at $100 million.

On March 9, a cut-off low pressure system impacted the Hawaiian Islands, bringing heavy rainfall and severe thunderstorms. Another storm dropped a hailstone measuring 4.25 inches long, 2.25 inches tall, and 2 inches wide–the largest hailstone on record for Hawaii. Damage from the storms was estimated at $37 million.
Several large extratropical cyclones impacted Alaska during September. Significant flooding occurred along the Sustina River and along its tributaries, causing the worse flooding in 30 years. More than 800 structures and dozens of homes were damaged or destroyed. The storms also brought early snowfall to southern portions of the state.

The Winter that Wasn’t

The winter of 2012 was unusally dry and warm due to record extreme jet stream configuration. The contiguous U.S. saw its third lowest snow cover on record during both winter and spring, and the winter of 2011 – 2012 was the fourth warmest and 24th driest winter in U.S. history.

Although it is small comfort to those hit hard by weather calamities, there is an upside to these destructive and costly meteorological phenomenon. These deadly and expensive events may lead Americans to embrace climate science.

As Sen Boxer (D-Calif), the chair of the Senate Environment & Public Works Committee declared: “Hurricane Sandy has shown us all what the scientists sitting right in this room said the day I got the gavel, & they told us exactly what would happen and it’s all happening.”

Extreme weather may auger much needed political change in Congress. As explained by Democrat Rep. Henry Waxman (Ca):

“It’s time to stop denying science. Extreme events like the wildfires in Colorado and the floods in Florida are going to get worse unless Republican-controlled Congress changes course soon.”

Extreme weather may prove to be an important catalyst in efforts to build support for the war on climate change.