SWOP Weekly Weather Discussion

HEADLINE

A taste of fall weather will continue for the next couple of days...followed by a significant warm-up by the middle and end of next week.

DISCUSSION

An unseasonably deep upper-level trough of low pressure centered near Hudson Bay will continue to be the driving force in the weather across central Illinois for the next couple of days. Thanks to deep-layer northwesterly flow around this feature, below normal temperatures will prevail through Monday, September 8th. Afternoon highs will only reach the lower to middle 70s while overnight lows dip to chilly readings in the lower to middle 40s. As the upper low begins to weaken and lift northeastward, upper heights will rise and temperatures will climb back to near normal for this time of year in the lower 80s by Tuesday, September 9th. After that, models have been consistently showing a significant pattern change...featuring a trough of low pressure digging across the Pacific Northwest and Northern Rockies with downstream ridging building over the Plains and Midwest by late next week. As a result, temperatures will rise well into the 80s and could even reach the lower 90s by next weekend. No significant rainfall is expected.

The latest 6-10 day outlooks (Sep 11-15) from the Climate Prediction Center (CPC) suggest NEAR normal temperatures and BELOW normal precipitation across central Illinois.

Issued: 9/6/25