Thursday, September 21, 2006

Weather Event #...I lost count long ago-August & September tornado events; and musings on another screwey "tornado season"

Well, 2006 like 2005 before it just further proves that the weather will do whatever the hell it wants, when it wants. Averages are merely a mean of extremes.

After a fast start with several monster outbreaks in March and early April that raised chaser's hopes for a big year; followed by less significant but still considerable activity through early May, the 2006 tornado "season" completely died. After the Westminister, TX tornado on May 9 (right before the weekend when most chasers from all over the country and even the world had scheduled the start of 2 or 3 weeks of vacation time to make their annual pilgrimage to the Plains), a massive ridge scoured the moisture out of the atmosphere and shut down virtually all tornado activity. The next tornado rated at least F3 in the United States would not be until the beginning of August, which I posted about below.

A few weather systems managed to force their way through the ridge during the mid/late spring and early summer, but by and large they only served to further frustrate chasers. There were days like June 6 and 18 in Wisconsin; which produced tornadoes after most chasers had decided the situations were too iffy to be worth the time and $2.95 a gallon gas. There were days like June 20 in western Iowa, when many chasers made the trip for what appeared to be the most promising tornado setup in over six weeks. After what was (for my chase partners and I) a 5-hour journey, we watched those extremely favorable tornado parameters fizzle in an atmosphere that refused to yield a single storm cloud.

During July and most of August the central states baked under one of the hottest summers on record. August 23rd looked like a very favorable local setup for tornadoes over southern Wisconsin, even more so like August 18 of the previous year (!). However it was the chase that never was for Scott Weberpal and I. Scott came over to my house and we hung around for several hours pouring over weather data until it became clear that like June 20; things would not be coming together after all. At least we didn't have to drive 5 hours each way on that expensive gas!

The next day, August 24; brought the first significant tornado outbreak since April. Numerous tornadoes developed across South Dakota and Minnesota. Unfortunately, several were quite destructive and even deadly.

Chase report by Simon Brewer
Chase report by Dean Cosgrove
Chase report by Bill Doms
Chase report by Mike Hollingshead
Chase report by Aaron Kennedy
Chase report by Melanie Metz
Chase report by Scott Olson
SPC Storm Reports log

The next significant severe weather event took place from September 15-16. A deadly tornado hit Rogers, Minnesota after sunset on September 16, with no tornado warning in effect. The storm had intensified extremely rapidly in between radar scans.

September 15:
Surprise, NE F2 tornado
Buffalo County, NE tornado
SPC Storm Reports log

September 16:
Chase report by Bill Doms
Chase report by Andrew Fischer
Chase report by Dick McGowan
Chase report by Scott Olson
Rogers Tornado-NWS Twin Cities
Southeast South Dakota tornadoes
Thunderstorm Damage from September 16-NWS Hastings, NE
SPC Storm Reports log

Another round of severe weather began on Thursday, September 21. An F1 tornado hit Russell, Kansas as part of an outbreak of cold-core mini supercell tornadoes.

NWS Wichita, KS
Chase Report by Simon Brewer

As I write this (updating on Friday 9/22), PDS tornado watches are in effect for parts of Arkansas, Missouri and Oklahoma and will probably be issued into central and southern Illinois later. In 2005, November was the biggest month for tornadoes out of the year. Could September turn out to be the most active month for tornadoes in 2006? We shall see, although it'll take quite an outbreak to beat March and early April.

Meanwhile, the 2006 Atlantic hurricane season; hyped by the media as a likely repeat of last year's abberation, has been nothing if not completely benign. The only storms that have made landfall have been mere tropical storms. The strongest system, Hurricane Helene (which peaked at a 125 mph category 3, same as that of Katrina at landfall) curved out to sea well away from the U.S. coast along with all the other Cape Verde storms that have formed. Averages are just a mean of extremes. Another example: Wisconsin's 2005 tornado count: 62 2006 YTD (and highly unlikely that we will see more): 10 (all F0-F1).