After a sizzling start to September; one of the warmest on record, the pattern flips as temps drop below normal Friday through Sunday.  Scattered showers and t-showers this morning and afternoon signal the change as a cold front sweeps across the state.  This front will clear Southeast Wisconsin by the evening and with a wind shift to the north our cool down begins.

The upper air pattern also supports a cooler fall-like forecast.  As the image below shows, the jet stream buckles into a large trough of low pressure over the Great Lakes.  This allows for cool air to settle south out of Canada.  It's no \"Polar Vortex,\" but it is a pattern reminiscent of cold winter days.

By Friday morning temps will be in the low to mid 50's with high temps only recovering to the low to mid 60's.  High pressure builds in for the weekend which will provide more sunshine; however, temps remain only in the mid to upper 60's for highs... generally 5-10° below normal.

Typical for this time of year, temps will swing back above normal as highs soar to near 80° through the first half of next week.