AFTERNOON – OVERNIGHT: The rain that moved through the forecast area overnight has moved off to the east this morning. While there are still a few isolated of rain around we are mostly dry.
The primary focus today will be a cold front that is currently in place to the northwest of the forecast zones. As this moves off to the east and southeast this afternoon rain and thunderstorms will develop along the front and impact portions of the forecast area.
While most of the morning hours will remain dry across zones 6 and 7 a few isolated areas of rain will remain possible. However, as the cold front starts to move into the region this afternoon more rain and thunderstorms will develop along the front. By 12-1 PM new development looks to be occurring across northern portions of zone 7.
By 2-3 PM storms will continue to develop along the forward advancing cold front. These will likely start developing across zone 7 then blow up north to south along the front.
By 4-5 PM the storms will be quickly racing off to the east and southeast, along with the cold front. At this time the front and storms will be moving into Indiana and across southern portions of zone 6.
By 7-8 PM most, if not all, of the storms will be off to the east and southeast of the forecast zones.
Right now it does looks like there will be break for at least some afternoon sunshine. This sunshine will help destabilize the environment. The latest model runs show in general 1000-1500 J/Kg of CAPE with a bit more in very southern Illinois where more sunshine could get through. While these values are lower than yesterday’s forecasts, it is still plenty of instability to aid in severe thunderstorm development this afternoon.
Aloft, very strong winds will be racing through the region. At 500 mb a southwesterly wind of 95-110 mph will be moving across the forecast zones. A little lower in the environment, at 850 mb, winds will be moving in from the southwest at 40-50 mph. With the increasing winds with height, it will create upper level wind shear or that spin aloft needed to create severe storms.
With that mentioned, I do think severe weather will be a threat across the eastern half of Illinois this afternoon. The latest risk from the SPC does have places in a slight risk of severe weather today. However, if more sunshine can get through I wouldn’t be shocked to see an enhanced risk issued. Main risks will be damaging winds and hail. However, a few isolated tornadoes can’t be ruled out.
New rainfall totals through this evening will be around .15-.35″ in many locations. However, places that do get under the strong/severe storms could see .90-1.20″ locally.
Overnight a few showers may linger across the area after the cold front passes. However, I think most places will be dry through the overnight.
Lows will fall into the upper 30’s north to mid 40’s south.
FRIDAY: An upper level trough will move through the area of Friday. As it does it will keep the weather cool and unsettled.
By 7 – 8 AM Friday morning isolated rain showers will be possible primarily across northern zone 6 and zone 7.
As a couple of pieces of energy move across the zones through the day on Friday isolated to very widely scattered showers will be possible across both zones through the day.
Highs on Friday will be in the low 50’s north to low 60’s south. Winds will remain strong with gusts up to 35 mph possible.
Friday night into Saturday the models do show dry conditions across the area.
Lows will be chilly Friday night as they dip into the low 30’s to low 40’s.
WEEKEND: Saturday we will continue to be influenced by the upper level trough. Through the day another piece of energy looks to move across the region. However, the main part of it looks to move to the northeast of the zones.
With the main energy to the northwest we should have a mostly dry day with perhaps a very isolated light shower in a few places.
Highs on Saturday will be in the lower 50’s north to lower 60’s south.
Winds on Saturday will be very strong. Sustained winds of 12-25 mph and gusts up to 55 mph will be possible!
Overnight Saturday into Sunday winds will start to calm and whatever clouds are in place will move out. Overall this will be the recipe for a chilly overnight.
Lows Saturday night into Sunday will drop into the mid 20’s north to mid 30’s south.
Sunday a surface area of low pressure will ridge into the forecast area ahead of another developing area of low pressure to the northwest.
This will create pretty nice conditions across the forecast area for Sunday. I expect sunny to mostly sunny skies across the region.
Temperatures will be warmer too with highs in the upper 40’s north to around 60 south. While winds won’t be as strong, gusts of 20-25 mph will remain possible.
SUNDAY NIGHT – MONDAY: By late Sunday night into the day time hours Monday an area of low pressure will start to approach the region from the northwest. As it does it will bring isolated to scattered rain chances with it.
While it does look like it will be a damp start to the week, current forecast guidance would suggest the rain will be out of the region late Monday afternoon/evening.
Highs on Monday will be very different from north to south. Where the front moves through early on in the day, high will likely only be in the low to mid 50’s. However, farther south where the front moves through late in the day, highs could reach the mid to upper 60’s!
7 DAY FORECAST
FRIDAY: MIX OF CLOUDS AND SUN, 20% CHANCE OF RAIN SHOWERS. HIGHS IN THE LOW 50’S NORTH TO LOW 60’S SOUTH. WINDS FROM THE WEST/NORTHWEST AT 8-16 MPH, GUSTING TO 35 MPH.
FRIDAY NIGHT: MOSTLY CLEAR TO PARTLY CLOUDY, COLDER. LOWS IN THE LOWS 30’S NORTH TO LOW 40’S SOUTH.
SATURDAY: MIX OF SUN AND CLOUDS 10-20% CHANCE OF AN ISOLATED RAIN SHOWER, WINDY. HIGHS IN THE UPPER 40’S NORTH TO LOW 60’S SOUTH. WINDS FROM THE WEST TO NORTHWEST AT 12-25 MPH, WIND GUSTS OF 45-55 MPH POSSIBLE.
SATURDAY NIGHT: MOSTLY CLEAR AND COLD. LOWS IN THE MID 20’S NORTH TO MID 30’S SOUTH.
SUNDAY: SUNNY TO MOSTLY SUNNY WITH HIGHS IN THE UPPER 40’S NORTH TO AROUND 60 SOUTH. WINDS FROM THE SOUTH AT 5-15 MPH, GUSTING TO 25 MPH.
SUNDAY NIGHT: INCREASING CLOUDS WITH A 10-20% CHANCE OF A RAIN SHOWER NORTH. LOWS IN THE UPPER 30’S NORTH TO NEAR 50 SOUTH.
MONDAY: MOSTLY CLOUDY WITH A 30% CHANCE OF RAIN AND A FEW T’STORMS. HIGHS IN THE LOW 50’S NORTH TO THE UPPER 60’S SOUTH. WINDS FROM THE NORTHWEST AT 5-15 MPH, GUSTING 25-35 MPH.
MONDAY NIGHT: DECREASING CLOUDS, RAIN ENDS. LOWS IN THE MID 20’S TO MID 30’S.
TUESDAY: MOSTLY SUNNY AND COLDER, RAIN FAR WEST? HIGHS IN THE LOW 40’S TO LOW 50’S.
TUESDAY NIGHT: INCREASING CLOUDS WITH A 20-30% CHANCE OF RAIN SOUTHWEST. LOWS IN THE LOW 30’S TO LOW 40’S.
WEDNESDAY: PARTLY CLOUDY WITH SCATTERED AFTERNOON RAIN/STORMS. HIGHS IN THE UPPER 50’S TO UPPER 60’S.
WEDNESDAY NIGHT: CLOUDY, RAIN AND STORMS ENDING. LOWS IN THE UPPER 30’S TO MID 40’S.
THURSDAY: MOSTLY CLOUDY WITH ISOLATED TO SCATTERED AREAS OF RAIN SHOWERS. HIGHS IN THE LOW 40’S NORTH TO LOW 50’S SOUTH.
THURSDAY NIGHT: PARTLY TO MOSTLY CLOUDY, COLD. LOWS IN THE MID 20’S TO MID 30’S.