AFTERNOON-OVERNIGHT: Rain showers and some fog continue across zones 6 and 7 this morning. The continuing showers are thanks to an area of low pressure at the surface, as well as low pressure aloft. Those features are doing a good job keeping the environment stirred up.
Through the morning into the afternoon clouds will start to erode and clear out. This will give way to some sunshine across the forecast area. However, with the upper-level disturbance still in the forecast region more isolated showers will develop across eastern Illinois around 12-1 PM.
Through the afternoon more isolated showers will develop, mainly across zone 6, these will be moving off to the south. By 4-5 PM the HRRR shows some of those isolated showers across the forecast zones.
Once the sun starts to set and we lose daytime heating/instability the afternoon showers will start to quickly fade out. By 8-9 PM there doesn’t look to be much left precipitation wise.
New rain accumulations look minimal with most places seeing less than .15”. However, a couple localized areas could see around .25” through the evening.
Overnight the area of high pressure will build in from the north. As it does, it will allow clouds to thin out across most of the area. Thusly giving way to clear to mostly clear skies across the region. However, there is a chance some areas across zone 6 could see some patchy fog overnight.
Lows tonight into Saturday will be in the low 40’s north to low 50’s south.
SATURDAY: High pressure will be in control of the weather on Saturday, this will really set the stage for a very nice weekend! Skies tomorrow will be sunny to mostly sunny across Illinois.
Highs on Saturday will be in the mid 60’s north to mid 70’s far south. Winds will be from the north at 5-15 mph.
Saturday night mostly clear skies will remain across the forecast area.
Lows will be in the upper 40’s east to mid 50’s west.
SUNDAY: The area of high pressure will move off to the east of the region on Sunday. To the west an area of low pressure will be moving across the northern Great Plains region. A warm front will extend off of the low to the north of the forecast area on Sunday.
However, the front will be far enough north it will not bring in precipitation chances to the area. In fact, mostly sunny skies will remain in many places with only some high clouds working in through the afternoon.
Winds will shift out of a southerly direction on Sunday allowing for warmer air to overspread the region. Highs on Sunday will be in the mid 70’s to around 80!
MONDAY: The surface low across the northern Plains will start to move to the east Sunday night into Monday. The low will move to the north of the forecast area on Monday. To the south of the low a surface boundary looks to be in place. Along this boundary isolated to widely scattered areas of rain and storms will develop in the afternoon.
Highs on Monday will be in the mid 70’s to around 80.
It isn’t totally out of the question that some t’storms Monday afternoon could be on the strong side. With some sunshine in the forecast instability should build across the area through the day.
Aloft, 500 mb winds will be out of the southwest at 45-55 knots. Winds at 850 mb will be coming in from the southwest at 35-45 mph. While this is not overly impressive, at least some strong storms would be possible if, and where, the greatest instability and upper level energy interact.
Monday evening into the overnight the cold front will continue to the south across zones 6 and 7. Rain and storms will continue along the front.
TUESDAY: Model solutions do vary for Tuesday regarding the timing/placement of the cold front. The GFS takes the front to the south of the region before stalling it in place ahead of another developing low pressure system.
If this would verify then drier, cooler conditions would be likely on Tuesday.
However, the EURO stalls the front out farther north more across southern Illinois/southern Indiana. With the front in place Tuesday some isolated to scattered rain and storms would remain possible, especially across southern zones.
We will call for highs on Tuesday to be in the low 70’s north to around 80 south. However, temperatures will be highly dependent on the placement of the front.
WEDNESDAY: We will be watching the weather very closely by Wednesday afternoon as a severe weather event is already looking possible across the region.
A strong surface low pressure and cold front looks to move into the forecast area Wednesday. As it does, impressive upper and lower level energy will accompany it.
Storms look to develop along the warm and cold front through the afternoon/evening. As these move across the region they will feed off of the instability and energy in the environment they are in. Right now timing, placement, and threats will have to be fine-tuned over the next several days. None the less, at least the ingredients for a regional severe weather event appear to be coming together in the long-range forecast.