National Overview - Annual 2011
2011 National Top 10 Weather/Climate Events

« National Overview - Annual 2011

2011 National Top 10 Weather/Climate Events

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2011 National Top Ten List

Rank Event When Occurred Event Description More Information
1 Tornado Super Outbreak April 25-28, 2011 On April 25-28, the largest tornado outbreak ever recorded (343) leveled the southeast U.S. There were 199 confirmed tornadoes and 316 tornado-related fatalities on April 27th, both are modern-day records for a 24-hour period. Spring Extremes Special Report
2 Southern Drought Throughout 2011 Extreme, persistent heat, combined with minimal precipitation, defined the most "intense" one-year drought on record - by several drought metrics - for large portions of the Southern Rockies, Southern Plains and into neighboring Louisiana. The calendar year 2011 was the driest on record for Texas. Spring Extremes Special Report
3 Joplin Tornado May 22, 2011 An EF5 tornado tracked through the heart of Joplin claiming 158 lives. It was the deadliest tornado since 1947 and seventh deadliest in U.S. history. It is also the costliest single tornado in U.S. history. Spring Extremes Special Report
4 Mississippi and Ohio River Flooding May Much of the central U.S. received up to three times of normal spring rainfall, and four Ohio River states (KY, OH, PA, WV) had their wettest spring on record. Record and near-record flood stages occurred throughout the lower Mississippi and Ohio River systems, many exceeding the legendary floods of 1927 and 1937. Spring Extremes Special Report
5 Hottest Statewide Summers on Record Summer (Jun-Aug) Texas, Oklahoma, New Mexico, and Louisiana had their warmest summer on record in 2011. Oklahoma and Texas both exceeded the record for the two warmest summer statewide temperature for any state in the Union (OK 1st and TX 2nd). Summer National Report
6 Hurricane Irene August 20-29, 2011 The first landfalling US hurricane since 2008, Irene made 3 landfalls along the Atlantic coast, disrupting power to over seven million homes and businesses and spawning numerous tornadoes. At least 45 fatalities occurred with over $7.3 billion in damages. August Tropical Cyclones Report
7 North Plains / Midwest Flooding June Meltwater from an above average winter snowpack, combined with warm spring temperatures and above average precipitation made its way into the rivers and streams of the Missouri River system. Record flooding resulted across the Northern Plains and Upper Midwest in June. Spring Extremes Special Report
8 U.S. Wildfire Season Throughout 2011 The Spring-Fall wildfire season across the southern U.S. broke numerous records. Texas had its most destructive fire of the modern record - destroying over 1,500 homes - while Arizona and New Mexico had their largest. Spring Extremes Special Report
9-tie Tornado Outbreak April 14-16, 2011 The outbreak covered a swath of land from Oklahoma to North Carolina and at the time was the largest tornado outbreak on record, being surpassed two weeks later. Thirty tornadoes were verified in North Carolina, breaking the state record for the number of tornadoes during one day. Spring Extremes Special Report
9-tie Tropical Storm Lee September 1-11, 2011 Lee made landfall on the parched Gulf Coast, where impacts were major, and mixed (drought relief, but with severe local flooding). The remnants' slow churn across the already-soaked Ohio Valley and Northeast brought continued misery the region, and floods of historic proportions to Binghamton, NY and Hershey, PA. September Tropical Cyclones Report

2011 National Honorable Mention

Event When Occurred Event Description More Information
Early Season Nor'easter October An early season snow storm broke records in several locations, including New York City?s Central Park, where 2.9 inches of snow fell. The highest snowfall amounts were further inland, with more than 30 inches accumulating in western Massachusetts and southern New Hampshire. October National Report
Extremes in CONUS PDSI January-November USCEI extremes in PDSI (Palmer Drought Severity Index) covered a record 56% of the CONUS (32% wet PDSI and about 24% dry PDSI). Numerous cities across the Midwest and Northeast broke annual precipitation records. Conversely, a number of locations in the southern plains experienced a record dry annual period. November Drought Report
Extratropical Storm November Perhaps the most powerful storm to affect Alaska's Bering Sea coast since the early 1970s. Wind gusts were measured at 89 mph, storm surge up to 7 feet high with 35 foot waves. November National Report
Groundhogs Day Blizzard January 31 - February 2, 2011 At least 5 inches of snow fell across 22 states with 1-2 feet of snow covering a large area across OK, KS, IA, MO, IL, WI, IN, MI and into New England. Chicago reported its 3rd largest snowfall with 20.2 inches reported at O'Hare Airport, which was also the biggest snowstorm on record for the month of February. Regional Snowfall Index
CONUS Heatwave Summer (Jun-Aug) Despite cool temperatures across the Northwest Region, summer was the 2nd warmest on record for the CONUS with the bulk of the warmth occurring across the Deep South and extending from the Southeast into the Northeast. A large number of 100 degrees F days occurred across a much of the South. Summer National Report
Winter Snowfall Records Winter (December 2010 - February 2011) & Snow Season (July 2010 - June 2011) During the winter season, many locations across the Midwest and Northern Plains broke snow fall records. Winter Snow and Ice Report
Haboob July 5, 2011 A very large and historic dust storm moved through a large swath of Arizona during the late afternoon and evening hours of July 5, 2011. Widespread reports of near zero visibility and winds gusting over 50 MPH (80 kph). It is estimated that this dust storm reached heights of 6000 ft. NWS Phoenix Report
Extremes in CONUS 1-Day Precipitation Spring (Mar - May) USCEI extremes in 1-day precipitation reached a record high with approximately 16% of the CONUS impacted. USCEI Spring 1-Day Precipitation
Northeast Snowfall Records January - February Several locations, including New York?s City?s Central Park and Philadelphia, were affected by major snowstorms which ranked in the top ten in history. Combined with the earlier snowstorms, January was the snowiest on record in New York, Newark, Bridgeport, and Hartford. NESIS Snowfall Map
Santa Ana Winds November - December A powerful Santa Ana windstorm whipped through mountain passes and canyons across the West and Southwest beginning on November 30 and continuing into December. NCDC November National ReportNOAA Viz Lab Graphic
Oklahoma Extreme February February Within the span of two days, two statewide records fell: 24-hour snowfall (2011, in the wake of snow associated with the Groundhog's Day blizzard, snow-packed Nowata, Oklahoma recorded a low temperature of -31 degrees F, breaking a record first established 84 years earlier. By the end of the week, temperatures had reached the 80s in much of the state. Bartlesville experienced a seven-day temperature swing of 110 degrees F (from -28 degrees F to 82 degrees F). All-time Climate Extremes for Oklahoma"
Dew Point Depression Record June 27, 2011 The temperature in Las Vegas reached 107 degrees F with a dew point temperature of -22 degrees F, the driest air on record for the city. The difference between the two yields a dew point depression of 129 degrees F and a relative humidity of 0.6%. June National Report