SUMMER OF '93 GOES DOWN IN RECORD BOOKS FOR FLOOD AND HEAT

While the summer of 1993 will long be remembered for the "Flood of the Century," Cape Girardeau residents will also remember it as the summer of severe storms and a return of heat and humidity.

According to Al Robertson, climatologist and professor of geo-sciences at Southeast Missouri State University, the summer of 1993 was the sixth warmest in 47 years of official weather data tabulation.

The hottest summers on record at Cape Girardeau occurred (in descending order) in 1980, 1952, 1954, 1953, 1983, and 1993.

Damaging thunderstorms, with winds in excess of 90-100 mph struck Cape Girardeau and a wide swath of Southeast Missouri and southern Illinois in early June, causing extensive property damage and uprooting hundreds of trees.

A second smaller, but almost as powerful thunderstorm with near hurricane force winds, ravaged the southern side of the city, causing widespread power outages that lasted up to 10-15 hours in some residential areas.

Robertson said the average temperature for the three-period, June through August, was 79.5 degrees, compared to the 47-year long-term average of 77.7 degrees.

Robertson explained the meteorological summer consists of June, July and August, for purpose of collecting and storing weather observation data.

"Following a very cool, initial 10 days in June, the temperature and humidity climbed dramatically, and continued to be very high for the remainder of the summer, except for the first two weeks in August," he said. "June's average was 75.7 degrees, .3 of a degree below the long-term average of 76 degrees. July averaged 83.6 degrees, a new record, and 4.2 degrees above the long-term average. August was also warmer than normal, with an average temperature of 79.2 degrees, up nearly two (1.8) degrees from the long-term average of 77.4 degree."

Robertson said there was one day last summer when the temperature reached 100 degrees, July 28. It was the first time in several years that 100 degree heat returned to the Cape Girardeau area.

"That's what made the summer of 1993 so unique - the lack of very high temperatures, even though it was warmer than normal. Once it was hot, it remained hot for most of the summer, especially in July. The difference was we only had one day when the temperature reached 100 degrees," he noted. "During July, there were 27 days when the temperature was at or above 90 degrees. This illustrates the high humidity readings that made everyone so miserable during July. With high humidity levels, the atmosphere does not cool down as much during the nighttime hours."

Robertson also noted that after any rainfall, there is usually a corresponding drop in temperature. "But in July, this did not happen during the six rainy days that month, he said.

Robertson said the culprit for the summer abnormal summer heat and humidity was the location of the jet stream. For most of the summer it was located well to the north of Cape Girardeau, traveling through Iowa and the Great Lakes area. He noted this position of the jet stream also set up the prolonged frontal boundary that dumped monsoon rains over the Upper Mississippi River Valley in June, July, and early August, that resulted in the Great Flood of 1993.

"At the same time, a ridge of strong high pressure from the Bermuda High built westward into the Southeastern United States which resulted in a severe drought in that area, and pumped vast amounts of hot, humid air from the Gulf of Mexico into Southeast Missouri and Southern Illinois," Robertson said.

"We did get some relief from the heat and humidity in early August, when the polar jet sagged southward far enough to allow some dry, cool, polar air to dip into our area. But the jet retreated back to the high plains by the middle of the month and allowed the warm, humid air to return from the south."

"However, if we think the hot summers of the early 1950s and 1980, 1983, and 1993, were hot, there are still many people around to remind us of the summers of the 1930s," Robertson added.

"According to unofficial but reliable records kept by professors in the science department at Southeast Missouri State College, there were 75 days in 1934 when the daily high was 90 or above. In July of 1934, there were 16 days when it was 100 or above. The hottest was 112 degrees on July 24, 1934."

But Robertson said even those temperatures are "cool," when compared to the summer of 1936, when the daily high was at or above 90 degrees on 81 of the 92-days of summer that year.

"The summer average temperature that year was 83.2 degrees, followed by 1934's summer average of 82.7 degrees. The only other 1930s summer that was warmer than 1993 was 1937, with an average of 79.9 degrees," Robertson said.