The heat and humidity return to the Stateline.

High pressure which provided the Stateline with an extended period of dry comfortable weather has shifted off to the east just to the north of New York State.  A fairly strong pressure gradient will exist across the region today leading to brisk southerly winds running 10 to 18 mph with early afternoon gusts to around 25 mph.  It will be a hot and humid afternoon with high temperatures approaching 90 degrees.  Deep moisture from the Gulf of Mexico will push across the area ahead of the trough.  That will lead to shower and thunderstorms development this afternoon.  Showers and storms over northeastern Missouri and Iowa will push into the northwestern part of Illinois this afternoon, and may scatter as far east as Rockford later this afternoon.  A thunderstorm complex is anticipated to be over Iowa tonight, and it will push across north central Illinois later tonight and early on Saturday.  With lots of moisture in place, the trough of low pressure approaching, and an upper level disturbance moving eastward across Iowa overnight, locally heavy rainfall is possible. Widespread rains of an inch or more can be expected, with some area receiving up to two inches.  Rain showers should end by mid-day on Saturday with the passage of the cool front.  Drier air will move in behind the front, skies will become partly cloudy, and the high of Saturday afternoon will reach the mid 80's.
On Sunday surface high pressure over Ontario will push a northeastern air flow across the region..  It will not be that cool, however, because warm high pressure will be building through the mid levels of the atmosphere.  Sunday will be a sunny day with a high in the middle 80's.  On Monday the ridge will be firmly in place and it will warm to the upper 80's under sunny skies.  On Tuesday the next cool front will push across northern Illinois setting up the possiblity of some thunderstorms.  A strong Pacific high will follow in behind the cool front on Wednesday bringing sunny skies to the Stateline Wednesday and Thursday along with mostly sunny skies and cooler temperatures.
By Meteorologist
Eric Nefstead