Is weather more severe?
by CRAIG JAMES
I had a good laugh a couple of months ago when the mayor of Moscow promised there would be no snow in that city this winter because he was going to have the clouds seeded, causing all of the snow to fall somewhere else. Well, his plan hasn’t worked too well so far. As of Christmas, about 20 inches had fallen on Moscow this season, with more to come. The first heavy snowfall was apparently way under forecast by meteorologists, which prompted one city official to demand “serious consequences” for the head of the city’s weather service. Sounds like a trip to Siberia to me.
By the way, 63% of the United States had an inch or more of snow on the ground this past Christmas Day. The only states that didn’t have any snow were Louisiana, Mississippi, Alabama and Florida. Oklahoma City received its biggest snowfall of record with 14.1 inches.
There was apparently a problem with the article I wrote for the December 24 issue of this paper; half of it didn’t get printed. So here, hopefully, is the entire section where I take a look at whether tropical storms have become more numerous and more intense.
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/.
The chart here shows the accumulated cyclone energy numbers for the Northern Hemisphere on the bottom line and for the entire globe on the top line. There was a trend up from 1979 until around 1993, but there has been a trend DOWN since then. In fact, tropical storm activity in 2008 and 2009 has been near a 30-year low both globally and in the Northern Hemisphere. The forecasts of increasing frequency and intensity of tropical storms have been incorrect.
In fact, a study in the Journal of Climate, March 2008, found that in the North Atlantic: “it is improbable that the number of tropical cyclones has increased since 1966… In addition, the rate at which storms become hurricanes appears to have decreased,” also, “little evidence is found that mean individual storm intensity has changed through time, although the variability of intensity has certainly increased. This increase is probably due to changes and improvements of intensity measurements,” and, “This model was recently applied to worldwide tropical storms and resulted in similar conclusions.”
In November 2006, the World Meteorological Organization held a conference on tropical cyclones and climate change. In dealing with the issue of how large a trend there will be in tropical cyclone intensities due to climate change, the conclusion was, “This is still a hotly debated area for which we can provide no definitive conclusion.” The full statement can be downloaded at www.wmo.ch/pages/prog/arep/tmrp/documents/iwtc_statement.pdf.
From what you hear in the mainstream media, you’d probably never guess this information was readily available. Every strong storm, tropical or not, seems to be blamed on global warming when there has actually been a decreasing trend in these storms. I’ll take a look at whether there has been an upward trend in tornado frequency and intensity in my next article.
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.