Severe Weather

Words on Weather & Climate

January 7, 2010 // 0 Comments

Trends in severe weather  Politicians, and even others who should know better, have stated frequently there would be an increase in the intensity and frequency of severe storms due to global warming. But in last week’s article I showed you that the tropical storm activity across the globe is now near a 30-year low. This week, let’s take a look to see if there has been an increase in tornadoes. According to the National Climatic Data Center, “With increased national Doppler radar coverage, increasing population, and greater attention to tornado reporting, there has been an increase in the number of tornado reports over the past several decades. This can create a misleading appearance of an increasing trend in tornado frequency. To better understand the true variability and trend in tornado frequency in the U.S., the total number of strong to violent tornadoes (EF3 to EF5 category on the Enhanced Fujita scale) can be analyzed.” For further details on this subject, visit You can see from the graph in Figure I that there was an increase in the number of strong tornadoes up until 1974, but there has been a DECREASING trend since then even though the number of people seeing and reporting tornadoes has increased. This is exactly the opposite of what has been forecast. There have also been forecasts of increasing droughts and heavy precipitation events. I haven’t found a graphic to show this on a global scale, but the National Oceanic and Atmospheric Administration (NOAA) has compiled one for the United States. In Figure II, the top graph shows the percentage of the United States experiencing moderate to extreme drought for each year since 1900, and the bottom graph shows the percentage experiencing moderate to extreme wet conditions. About 80 percent of the United States was in moderate to extreme drought in the mid 1930s, but there certainly doesn’t appear to be much of an overall change in either extremely dry weather or wet weather since 1900. Going back to A.D. 1200, it appears the worst drought in North America occurred in the 1500s. According to an article in Science Daily (Feb. 8, 2000), “No other drought appears to have been as intense, prolonged and widespread as the 16th century megadrought,” and, […]

Words on Weather & Climate—December 23, 2009

December 23, 2009 // 0 Comments

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 […]