Marshfield News-Herald from Marshfield, Wisconsin • 37

Outdoors Morshfield Newt-Harold Thurtdoy, June 3, 1982 Page 13 Worst forest fires start after short drought air to Wisconsin. At such times, frontal systems still pass through the state, but they bring little rain, says Lorimer. Although the fronts don't generate more lightning that the typical storms, lightning strikes during such dry conditions are more likely to start fires than they usually do. Susceptibility of an area to large fires depends on the fuels present. "There is a tremendous differencce between fuels," says Lorimer.

"The worst fires tend to be fires in slash on open lands like the Peshtigo Fire or fires in pine stands on sandy soils because they dry out quickly. Although weather conditions comparable to those before the Peshtigo Fire happen every few years, another Peshtigo Fire isn't likely because we have no areas with that tremendous accumulation of slash." Wisconsin's worst recorded forest fire occurred Oct. 8, 1871. The Peshtigo Fire destroyed 1,235,000 acres in eight counties. Now, University of Wisconsin-Madison forest ecologist Craig Lorimer has found some unexpected relationships between weather conditions and forest fires in northeastern Wisconsin.

Since the Peshtigo Fire, the 17-county area he studied has experienced 15 summers with worse drought conditions than 1871. years with major fires notable 1871, 1891 and 1894 did not have prolonged droughts of unusual severity," says Lorimer. During 1871 there were only five days of extreme drought. "The Peshtigo Fire simply happened to flare up during this period of extreme conditions," he explains. Lorimer and meteorologist William Gough analyzed the conditions conducive to large fires between 1864 and 1980.

By examining daily rainfall and temperature records from weather stations in three northeastern Wisconsin towns, and by using a mathematical computer model that keeps track of soil moisture, Lorimer has been able to reconstruct the history of summer droughts during the past 116 years. early October the lack of rain and low relative humidity created severe drought conditions that dried out the slash. After only a few days of such weather, the settlers' fires flared and merged. The ensuing holocaust took well over 1,000 lives. "Almost without excception, the great historic conflagrations occurred on days when the relative humidity was less than 40 percent," Lorimer says.

Anything below 30 percent is very unusual for Wisconsin. The day of the Peshtigo Fire the relative humidity in Madisou was only 24 percent and a few days before it had been 18 percent. Dead branches, twigs and leaves dry out quickly under such conditions. Lorimer found that although high winds aggravate fires, they aren't a requirement. Many major fires started on relatively calm days.

A characteristic weather pattern is common during drought conditions, says Lorimer. A high pressure cell usually stationed over Hudson Bay migrates south to the Great Lakes or Ohio Valley at the same time that the Bermuda High expands over the southeastern U.S. or the Gulf of Mexico. These conditions block the flow of moist air from the Gulf of Mexico and southwesterly winds bring warm, dry By nearly all critera, 1976 clearly ranks as having the most severe drought conditions in the 116-year period," says Lorimer. "In fact, the number of days of extremely dangerous burning conditions for 1976 is so much higher than any other year, that it is in a category by itself." People often speak of particularly bad fire years.

But one of the lessons from Lorimer's work is that severe fire weather can develop within weeks during almost any year. Major fires usually did break out during drought conditions, but these don't take an entire summer to build up. "We shouldn't think of the weather of 1871 as that unusual," Lorimer says. "Conditions comparable to those happen on the average of once every five years." The spring and summer of 1871 were failry wet, says Lorimer, Things started to dry out around Pestigo in September. On Sept.

16, 1.6 inches of rain fell the last the area was to receive before the fire 22 days later. During that summer, settlers around Pestigo were clearing land for farming and burning slash the debris left by loggers. Their fires smoldered for weeks and weather stations noted smoke in the air during September. By DAYS 100 90 80 DAYS OF EXTREME DROUGHT IN N.E. WISCONSIN 1864-1980' It's tick time again It's wood tick season again.

And Walt Gojmerac, University of Wisconsin-Extension entomologist, has some suggestions for dealing with these seasonal pests. Wood ticks are parasites which require a blood meal to reproduce, says Gojmerac. They are not insects but are closely related to them. Animals and humans usually pick up wood ticks in wild areas. However, ticks also may be carried into your yard on small wild animals or dogs.

Young wood ticks feed on small mammals squirrels, mice, rabbits or gophers while adult ticks prefer larger hosts such as humans or dogs. "After being outdoors, check yourself and your children to be sure there are no ticks embedded in the skin," advises Gojmerac. "If you do find a tick, don't be overly afraid simply remove it and destroy it." Dabbing a tick with alcohol or touching it with a hot match will not force the tick to drop off. You'll have to pull it off. Gojmerac explains that ticks cannot physically let go until they are completely engorged.

Because there is some broken skin, be sure to disinfect the spot that's usually all you need to do. he adds. However, if the wound does become inflamed, you may want to get some medical attention. For more information on ticks, contact the University of Wisconsin-Extension Office and reques publication G1993. "Controlling 70 60 50 40 30 20 10 I lil ijLo 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 YEAR The year 1976 ranks as having the most severe drought conditions in 116 years, according to a survey conducted by a University of Wisconsin-Madison forest ecologist.

This chart shows drought conditions for the years 1864-1980. Although drought conditions affect the occurence of forest fires, severe fire weather can develop within weeks during almost any year..