The forecast: A lot of drying out

Nothing but sun is expected in the forecast for the next several days.

That should help dry out the region after the worst three-day drenching since 1987. But that also might prevent Mother Nature from breaking a 47-year-old rainfall record for the month of September.

Meteorologists from the National Weather Service's Chicago forecast bureau said an average of 8.45 inches of rain fell on the area between 7 a.m. Friday and 7 a.m. Monday. That's about 1.5 inches less than the area averaged in a record-breaking three-day span in August 1987, but enough to come in second.

"This was actually caused by two tropical systems and a cold front one after the other," said Charles Mott, a local weather service meteorologist. "The culmination of the three events caused the rain to continue."

The remnants of Tropical Storm Lowell that had moved up from the Pacific Ocean started things off, followed by a cold front that was pushed out by the pressure from Hurricane Ike, Mott explained.

Weather stations at O'Hare Airport are used for the official regional rainfall counts, but the National Weather Service employs dozens of other stations throughout the area to get more thorough data. Sometimes larger cities have multiple monitoring sites.

A weather station in Wheaton recorded the heaviest dousing in Illinois with a count of 10.53 inches, but four locations in northwestern Indiana topped that total. Wheaton's three sites averaged 8.53 inches.

The region has now received 12.61 inches of rain for the month. The record is 14.17 inches, set in 1961, Mott said. The average September sees only 3.27 inches of rainfall.

Mott put the odds at about 50/50 for breaking the rainfall record for the month.

"This week will be dry, so I know that doesn't help," he said. "But on the other hand we're just an inch and a half shy and we're only halfway through the month."