Despite overall below-normal seasonal averages, including low number of tornadoes and hurricanes, the year packed a punch in terms of individual impactful events.
Atlantic Hurricane Season Spares US From Major Hurricanes
When the Atlantic hurricane season ended on Nov. 30, it marked the season with the fewest number of hurricanes since 1982, according to the National Oceanic and Atmospheric Administration (NOAA).
Thirteen systems spun up in the basin over the course of the season, but none developed into major hurricanes. Only two, Ingrid and Humberto, even strengthened into hurricanes this year compared to an average of six per season.
Though it was originally thought that the season would be more active than usual, several factors inhibited the development of strong storms.
"Above-normal shear across the Gulf into the northwestern Caribbean hindered development when it combined with a lot of dry air," AccuWeather.com Expert Senior Meteorologist and Long-Range Forecaster Bob Smerbeck said.
High wind shear, or rapidly changing wind speed or direction with altitude, can limit strengthening of tropical storms or hurricanes. It causes the center of tropical storms to be tilted rather than vertically stacked, a key to strong tropical systems.
Additionally, cold water nosing southwestward in the eastern Atlantic and a significant amount of African dust further stifled the set up for stronger, longer-lasting storms.
Tornado Season Yields Low Total Count But a Few Devastating Events
Severe weather season got off to an unusually slow start in 2013, convincing many that the year would be break records in terms of a low number of total tornadoes.
According to NOAA, the United States averages 1,253 tornadoes per year. As of Dec. 16, 2013, preliminary reports totaled 929, ranking the year below the average.
Preliminary reports are often higher than the actual number of occurrences due to duplicate reports.
Despite the below-average number, however, several devastating twisters left their mark across the United States this year.
On May 20, an EF-5 tornado touched down in Moore, Okla., leveling entire neighborhoods. Afterward, the town was barely recognizable to its residents. The storm also destroyed an elementary school, killing seven children.
On May 31, a tornado ransacked El Reno, Okla., becoming the widest tornado on record. The twister stretched across 2.6 miles and was rated an EF-5. At the time the tornado hit, only 60 twisters of comparable intensity had been recored since 1950.
Drought Eases in Much of US; Grows in California
Last year, drought gripped the majority of the contiguous United States, threatening a corn and soybean crisis for farmers, stressing the California reservoir levels and causing water levels on the Mississippi River to plunge at times.
In 2013, drought conditions have eased considerably. At the start of the calendar year, 72.78 percent of the contiguous United States was experiencing some degree of drought. As of Dec. 2013, however, that percentage has decreased to 44.51 percent.
Some states fared better than others, however. Eighty-two percent of California currently suffers from severe to extreme drought conditions. This report is significantly worse than the start of the year, when only 22.5 percent of the state was in the severe to exceptional drought range.
Haiyan Draws Worldwide Attention to Active Pacific Typhoon Season
Despite an already active Pacific typhoon season, Super Typhoon Haiyan commanded worldwide attention when it made landfall in the Philippines in November, killing more than 6,000 people.
The typhoon became the deadliest on record for the country and has been hailed as one of the strongest storms ever at landfall with estimated wind speeds of more than 200 mph.
The storm caused the most destruction in Tacloban City, where it was originally estimated that as many as 10,000 lives may be lost. Downed power lines, trees and other debris made the area difficult to access for many days after the storm.
Haiyan beat out Usagi, an extremely violent storm, as the strongest typhoon of the season.