Washington, D.C. (WUSA9) – This month's local weather pattern has brought record or near record warmth across much of the eastern United States. Christmas was one of the warmest on record in many eastern cities – including Washington, D.C., New York City and Burlington, Vermont. The warm air got as far north as the Canadian province of Quebec where temperatures reached the 70s.
Although many eastern cities are poised to set new records for their warmest December, much of the western United States has been colder and snowier than average. Blizzard conditions were observed earlier this week in eastern New Mexico and Texas. Such a dramatic difference in temperatures was caused by a significant trough (or dip) in the jet stream (a river of air in the atmosphere that guides air masses). This sharp difference between cold and snow out west and record warmth in the eastern U.S. has helped create favorable conditions for severe weather.
A severe thunderstorm features any of the following: hail at least 1" in diameter; wind gusts of at least 58 mph; or a tornado. NOAA data shows there has been a record amount of severe weather this month, including tornadoes. Colorado State University scientist, Dr. Philip Klotzbach, recently said "Tornadoes have been reported on 8 consecutive days (December 21 – 28), the most consecutive days on record for December, breaking the old record of 6 (in 1982)." Just like this winter, December 1982 was also in the midst of a strong El Nino event.
Unfortunately, more people have been killed (20) nationally by tornadoes this month than the rest of 2015 combined (10). Severe weather awareness on the part of the public, combined with improved detection and forecasting, have provided increased advance warning. That's helped reduce the number of severe weather fatalities in recent years across the United States. However, most people just don't expect severe weather – much less tornadoes – during the month of December.
The largest severe weather outbreak this month occurred on December 23, when there were nearly 350 reported cases of severe weather nationally – including more than four dozen tornadoes from Illinois to Alabama. Washington, D.C. hasn't had any severe weather this month, but has been wetter than average. More information on severe weather and the latest forecasts can be found both on-air and online (wusa9.com), as well as on the FREE wusa9 app – for your mobile devices.
