PLEASANT WEATHER WILL GIVE WAY TO HOTTER CONDITIONS

The National Weather Service says the pleasant, early-falllike weather the area has enjoyed the past few days soon will be replaced with hot and dry conditions more typical during the final two weeks of August.

Forecaster Scott Truett of the National Weather Service in St. Charles said the jet stream, which has been oriented most of this month in a northwestsoutheast direction over the Middle Mississippi River Valley, is returning to a typical, lateAugust westtoeast flow across the northern United States and southern Canada.

As the jet stream moves northward, Truett said it will cut off the northerly flow of air from Canada and allow a large area of strong high pressure to build over much of the nation, including Southeast Missouri and Southern Illinois.

"That's going to cause things to really heat up during the next five to 10 days," he said. "There will also be some increase in the humidity level, and that will make it seem even more uncomfortable."

Truett said the strong high pressure will lessen the chances of afternoon thunderstorms that would normally relieve the summer heat and provide needed rain.

The high Monday of 78 degrees at the Cape Girardeau Municipal Airport was a record minimum high for Aug. 19. The old record, 79 degrees, was set in 1977 and tied in 1985.

The low of 56 degrees on Tuesday was 6 degrees above the record low for the date and was the coolest morning here since May 7, when the thermometer dipped to 51 degrees. On May 6, the overnight low fell to 45 degrees.

Al Robertson of the earth science department at Southeast Missouri State University said the pleasant weather was the result of the northsouth kink in the jet stream that allowed several intrusions of cool and dry Canadian air into Southeast Missouri and Southern Illinois this month.

Robertson said the 10day average temperature for Aug. 11-20 was 74.7 degrees, down 2.6 degrees from the longterm average of 78.8 degrees. That was in sharp contrast to the first 10day period, when the average temperature was 81 degrees, up 2.1 degrees from the longterm average.

Robertson said the average temperature for the first 20 days of August was 77.9 degrees, a tenth of a degree above the long-term average. "If it hadn't been for the hot weather during the first 10 days of the month, we'd really have a cool month," he said.

But Robertson pointed out that although temperatures were warmer than normal during the first 10 days of the month, relative humidity levels have remained generally low during most of the past 20 days. Without the high humidity levels that are typical of August, Robertson said the heat this month has not been as noticeable to most people.

Rain at the airport during the first 20 days totaled 3.93 inches compared to the longterm monthly average of 3.8 inches. But Robertson pointed out not all areas received that much precipitation. "The day the airport got over 2 inches of rain, downtown Cape got about a halfinch," he said. "The rainfall in the area is extremely spotty this month."

The weather service said highs today and Thursday will return to the mid80s, to near 90 degrees, with partly cloudy skies. The extended outlook Friday through Sunday calls for little or no rain with highs in the 90s and lows in the mid70s.