Is weather more severe?
by CRAIG JAMES
Before I get to the main topic of this article, I’d like to point out what an amazing and severe turn to winter there has been across Canada and the United States this month.
For the seven-day period of Sunday, Dec. 6 through Saturday, Dec. 12, there were 815 new snowfall records, 304 low temperature records, and 403 lowest maximum temperature records set in just the United States alone.
On Sunday, Dec. 13, the temperature hit 51 degrees below zero with a wind chill of 73 below zero at Edmonton, Canada, for the coldest December day on record.
On Tuesday, Dec. 14, Jordan, Montana recorded a low temperature of 40 degrees below zero, which was 46 degrees below average.
The only warm weather in the country this month has been in Florida. Los Angeles and Phoenix were close to 4 degrees below average for the first two weeks of December, and even Honolulu, Hawaii was nearly 2 degrees below average.
It has been very wet in New Orleans. For the first two weeks of the month, over 24 inches of rain were measured in that city, making it the wettest month on record.
Valdez, Alaska received 77 inches of snow in four days on Dec. 14 through 17. They are so used to heavy snowfall there that schools stayed open!
And that brings me to the main point of this article: Has the weather gotten more severe? Are there stronger storms than in the past due to global warming? My answer to that, at least in regards to tropical storms and tornadoes, is definitely a resounding “NO!”
Let’s take a look at tropical storms first.
Complete coverage of tropical storm activity across the globe has only been possible since 1979 when satellites began monitoring these storms. Between 1944 and 1978, in order for there to be an estimate of a tropical storm’s strength, a reconnaissance aircraft had to fly into the storm or a ship had to be near the center. Prior to 1944, there were no aircraft flights into storms, so the only reports came from ships or when a storm made landfall.
The National Hurricane Center believes many storms were not recorded prior to these aircraft flights, and the peak intensity of storms out over ocean waters may well have been missed if there was not an aircraft or ship in the immediate vicinity at the time of the peak.
Since we have been able to monitor these storms nearly continuously since 1979, we now have a 30-year very reliable record of whether there has been a trend up or down in tropical cyclone frequency or intensity.
Ryan Maue from Florida State University has kept a chart of what is called Accumulated Cyclone Energy, which combines frequency, duration and intensity of tropical cyclones into one value. You can find all of the data online at www.coaps.fsu.edu/~maue/tropical/.
Craig James has been retired since July 1, 2008, after 40 years of broadcasting television weather. He was chief meteorologist at WZZM-TV for 12 years and chief meteorologist at WOOD-TV for 24 years. He is a graduate of Penn State University, where he received a Centennial Fellowship Award. He was also honored as a Fellow of the American Meteorological Society.