Temperatures should warm into the 80s Monday and a 90-degree high is possible Tuesday as southerly winds invade Northeast Illinois for a two-day stay. The upper-air steering-level winds that have been persistently out of the northwest for days have temporarily shifted more west to southwest. This change will allow the northern edge of very warm air that has been resting over the southern Plains to finally reach the Midwest. The west to southwesterly flow aloft extends to the Northeast coast and into the northern Atlantic, accelerating the movement of weakening Tropical Storm Bill tracking just to the south of Newfoundland and then east out into the northern Atlantic later Monday.
Cooler temperatures return midweek
The passage of a cold front Wednesday signals the shift of the upper-air pattern back to a northwesterly flow which looks to be a semi-permanent fixture the remainder of this week and next. There are indications the front may stall in central Illinois, which could mean extensive cloudiness over Chicago and a good chance of showers or thunderstorms -- especially in southern sections -- Thursday into Friday.
Cooler temperatures return midweek
The passage of a cold front Wednesday signals the shift of the upper-air pattern back to a northwesterly flow which looks to be a semi-permanent fixture the remainder of this week and next. There are indications the front may stall in central Illinois, which could mean extensive cloudiness over Chicago and a good chance of showers or thunderstorms -- especially in southern sections -- Thursday into Friday.
