This year's tornado season appears to be one for the ages. From the twister that stuck downtown Atlanta in March and the bevy of Mother's Day storms to the most recent funnel cloud that touched down May 20 in Cherokee County, we've seen more than our fair share of heavy-duty winds.

Georgia has had more tornadoes in the first five months of 2008 than it sees on average in an entire year, says Lans Rothfusz, chief forecaster for northern and central Georgia for the National Weather Service. In an e-mail, Rothfusz discussed with The Atlanta Journal-Constitution why the area — and the nation, for that matter — seems to have been hit with so much tornadic activity.

Q. Why have Middle and North Georgia seen so many twisters in such a short time?

A. It's a matter of weather patterns and how they establish themselves. Some years are active, some are not. This has just been an active year for us.

Q. What significant atmospheric changes, if any, could be contributing to this severe weather?

A. I wouldn't classify it as an atmospheric change; it is just the natural variability of weather in the Southeast. We have had several situations in which the atmospheric conditions were just right to produce strong storms with tornadoes. The fact that several of them, especially the Atlanta tornado, hit populated areas has generated more attention than usual, as well.

Q. How does history compare to this year in severe weather and tornadoes? Has Georgia seen more thunderstorm and tornado systems in the first half of the year?

A. Year to date, we have had 51 tornadoes reported in Georgia, which is more than double the average of 22 in a given year. Keep in mind that, in order to have an average, you'll have some years with above-average events, and some years with below-average events. This was obviously an above-average year for tornadoes. I wouldn't say that we've had more storm systems; it was about normal. It's just that they produced more tornadoes [or more tornadoes got reported] than in an average year.

Q. There have reportedly been nearly 900 U.S. tornadoes this year. Is that unusual, or on par for annual totals?

A. The annual average number of tornadoes for the U.S. (1953-2004) is 908, so we're already at the average less than halfway through the year. Keep in mind, however, that the spring is usually the most active time of the year.

Q. When was the last time metro Atlanta has seen this many tornadoes in a six-week period? Or has there been more?

A. That's a tough one. We don't keep records on a week-by-week basis for metro Atlanta (without doing some heavy research). Subjectively, however, I am probably safe in saying this has been one of the most active tornado seasons in the metro Atlanta area in some time.

Q. Can Georgians expect more of what we've seen since March? And when might it end?

A. We are approaching the end of the typical severe weather season. Tornadic storms drop off significantly in early June.

Q. How much truth, if any, is there to the idea that global warming is aiding in the creation of severe weather?

A. None. There is no verifiable evidence that global warming influences severe weather one way or the other. There are many theories, but no concrete evidence. Global warming is a climate phenomenon. Severe storms are weather. Climate is the aggregate of years of weather events, so pointing to a climate phenomenon as a possible cause of specific weather events is not appropriate.

Q. How does Georgia compare atmospherically to flatter, Plains states? Are conditions in "tornado alley" similar to Georgia's?

A. Atmospheric conditions that produce tornadoes are essentially the same everywhere because the laws of physics apply universally. There are differences in how the essential ingredients to produce a tornado might come together in Georgia versus the Southern Plains, but the ingredients are the same. Because those ingredients are slightly more common in tornado alley, they get more tornadoes. This year, however, those ingredients occurred in Georgia more often than normal.

Q. Why are we getting so many storms, but not so much in the way of actual, drought-busting rain?

A. The large-scale storm systems that spawned the tornadoes have been rather fast-moving and low in moisture. We didn't get as many slow-moving, wet storms this past winter which are necessary in helping replenish the water supply.