AFTERNOON – OVERNIGHT: A cold front continues to move across the forecast zones this morning bringing with it continuing rain and a few storms. Some of this rain has been heavy at times as it moves across zones 6 and 7.
While we are seeing a bit of a lull in rain across Illinois this morning, rain coverage will increase over the next few hours once again. By lunchtime pretty dense coverage of rain with a few t’storms will be in place from I-70 southward as the cold front continues off to the south and southeast.
Through the afternoon into the early evening the cold front will move off to the south and southeast. As the front exits the region, the rain and the few t’storms that are in place will come to an end from northwest to southeast this afternoon. By 4-5 PM most, if not all, of the precipitation will be out zones 6 and 7 giving way to drier conditions.
There are some indications that some sunshine could get through by late this afternoon into the evening, especially across northern zone 6 and 7.
Winds today will be gusty at times as the front passes through the area. Wind gusts of 30-35 mph will be possible.
Heavier areas of rainfall will remain possible from I-70 southward through the evening hours tonight. Models continue to show a pretty large swath of .75-1” totals before the rain ends this evening across zone 6. Places that do get under the heavier rain or a t’storm could see 1.10-1.50” of new rainfall locally in that area as well.
Through the overnight an area of high pressure will start to build in from the northwest. As it does, it will allow for skies to clear across Illinois from north to south.
Lows overnight will drop into the low 30’s north to upper 30’s south.
TUESDAY: An area of high pressure will move over the region on Tuesday and take control of the weather pattern. This will allow for sunshine to overspread zones 6 and 7 throughout the day on Tuesday.
However, the high will keep us cool across Illinois tomorrow with highs only around 50 north to around 60 south. Winds will be from the north to northeast at 5-15 mph.
Tuesday night into Wednesday clear to mostly clear skies will remain in place. This will allow temperatures overnight to once again fall just below or right at freezing to the north with lows in the low 30’s north to upper 30’s south.
WEDNESDAY: At the surface the large area of high pressure will move off to the northeast. However, it still will be ridged into the forecast area, so it’s overall influence will be “felt” across zones 6 and 7 as it will allow skies to remain sunny to mostly sunny with perhaps some clouds across northern zone 7.
However, the bigger transition will occur at the upper levels. Over the past week or so an upper-level trough has brought very cold and unsettled weather to the forecast area. However, Wednesday a big change will take place as an upper-level ridge will start to build into the eastern United States. This will be a major flip in the overall pattern!
The upper-level ridge will transition us into a calmer pattern with a gradual warming trend each day, starting on Wednesday! Highs on Wednesday will be around 60 north to mid/upper 60’s south.
THURSDAY – FRIDAY: At the surface high pressure will continue to control the weather across eastern half of the United States. This will allow for us to remain very quiet weather wise to end the week.
With the high in place dry, sinking air will really hinder cloud development so sunny to mostly sunny skies are expected both Thursday and Friday, with perhaps a few more clouds Friday afternoon across western Illinois.
Temperatures through the end of the week will continue to moderate nicely across the forecast area thanks to the upper-level ridge that will continue to pump up across the eastern U.S. and even into Canada! This ridge is really going to allow warmer air to surge into the forecast area by Thu/Fri.
Highs will be in the low 60’s north to around 70 south on Thursday.
However, widespread mid 60’s to low 70’s will be possible across Illinois on Friday! I will say, models have really struggled with warm air advection and underestimating high temperatures this year. So don’t be shocked if forecast highs for the end of the week creep up per forecast models each day!
LONG RANGE (WEEKEND): Surface high pressure and the upper-level ridge of high pressure will remain the dominate weather features over the weekend. This will allow for sunny to mostly sunny skies to remain in place across the region.
Temperatures will continue to warm with widespread 70’s both days!