SWOP Weekly Weather Discussion

HEADLINE

Much above normal temperatures will persist for the next several days...before a big cool-off arrives by the weekend of October 16-18.

DISCUSSION

As a deep upper-level low currently centered over Hudson Bay, Canada pivots northeastward, upper heights will rise across the Midwest over the next several days. After a slight cooling trend behind a weak cold front that will drop temperatures into the middle 70s to lower 80s on Thursday, October 8th...readings will steadily rise into the upcoming weekend. The warmest day will be Saturday, October 10th when highs will climb to near record values in the middle to upper 80s.

Meanwhile all eyes will be on Tropical Storm Isaias as it strengthens into a hurricane and makes landfall along the Gulf Coast of Alabama or the Florida panhandle Friday night into Saturday morning. All models suggest the system will rapidly track northward, spreading rain into the Tennessee and Ohio River Valleys over the weekend. Based on the synoptic pattern and most model guidance, it appears the heaviest rainfall in excess of 1 inch will stay just E/SE of central Illinois Saturday night into Sunday. A few showers may spread as far west as the Illinois River, but the most consistent precipitation will stay along and east of I-57 as the tropical system quickly ejects northeastward.

A return to very warm and dry conditions is expected on Monday, October 12th before a pattern shift brings a big airmass change by the end of next week. The East Pacific Oscillation (EPO) has become negative, which is indicative of upper ridging developing across the Northeast Pacific Ocean. Downstream troughing from the ridge will dig into the Pacific Northwest and Northern Rockies, then will eventually translate/dig eastward later in the period. Most models indicate passage of a significant cold front by next Wednesday/Thursday...followed by highs perhaps dropping into the 50s and lower 60s by next weekend.

The latest 6-10 day outlooks (Oct 13-17) from the Climate Prediction Center (CPC) suggest ABOVE normal temperatures and ABOVE normal precipitation across central Illinois.

Issued: 10/7/26