AFTERNOON-OVERNIGHT: Conditions across zones 6 and 7 remain pretty quiet this morning with clear to mostly clear skies. The only hazard out there is some patchy fog. That’s despite the cold front and stationary front that are in place across Illinois.
Through the morning into the afternoon the cold front and stationary front will move off to the east. As they do, most of the precipitation chances will exit the state with them. However, there will still be an occluded front in northern Illinois this afternoon. With that in place some showers may develop around 1-2 PM across zone 7.
By 5-6 PM some isolated rain showers will remain possible across zone 7 as the occluded front remains in place. However, with some steep lapse rates in place, I won’t rule out a few showers across northern zone 6 either.
Later in the evening the front will push-off to the east of the forecast zones. As this occurs and we lose daytime heating, any rain showers will quickly start to fade across zone 7.
Through the overnight clouds will be on the increase across the forecast zones, especially south. Lows overnight will be in the mid 40’s north to mid 50’s far south.
FRIDAY: Partly to mostly cloudy skies will remain in place throughout the daytime hours on Friday. I do think dry conditions will remain through at least early to mid-afternoon before another chance of rain moves in later.
Highs on Friday will be in the mid 60’s north to low 70’s south.
Through the afternoon an upper-level disturbance will move across the southern half of Illinois. As it does, it will allow for rain to develop. By 3-4 PM rain will be moving into zone 6 and 7.
By 6-7 PM scattered areas of rain and a few t’storms will remain possible across both zones 6 and 7.
Through the evening I think overall coverage will lessen, but scattered areas of rain and a few storms will persist by 10-11 PM Friday evening.
Through the overnight Friday we may see a lull in rain chances early. However, as a warm front start to lift closer to the region, more rain and storms will develop later overnight. By 3-4 AM more rain and storms will be moving into the forecast zones.
Lows overnight will be in the low 50’s north to near 60 south.
SATURDAY: By 6-7 AM Saturday morning the warm front will continue lifting northward across southern Illinois. With the warm front in place, rain and storms will also remain possible across both zones 6 and 7.
Through mid-day Saturday rain and some storms will continue across the forecast zones.
However, as we get into the afternoon a lot of the precipitation will lift off to the northeast of the forecast area. This looks to contribute to a drier afternoon and evening on Saturday. By 6-7 PM Saturday evening only some isolated to scattered areas of precipitation will be in place.
Highs on Saturday will be highly dependent on the location of the front. North of the front temperatures will only warm into the low to mid 60’s. However, south of the front temperatures will be in the mid 60’s to mid 70’s.
Saturday night the area of low pressure will start to track through portions of Illinois. The exact track of the low will be key in determining rain chances Saturday night into Sunday. The NAM/EURO solution would suggest the low goes through zone 6. With that placement rain and/or storm chances will be far less. However, if the low does go farther north rain chances would increase.
For right now I will call for isolated to widely scattered areas of rain Saturday night and will fine-tune those over the next 24 hours.
Lows Saturday night into Sunday will be in the low 50’s northwest to low 60’s south.
SUNDAY: The surface area of low pressure will move through the morning hours on Sunday. As it does, better rain chances will exit the forecast area with it.
However, the upper-level trough will be lagging behind a little. As this approaches the region and moves through Sunday afternoon/evening some more isolated to widely scattered rain showers will remain possible. Better rain chances look to exist the farther north you go on Sunday.
Highs on Sunday will be in the low 60s north to mid 70’s south. Winds will be breezy out of the northwest at times with gusts of 20-25 mph possible.
New rainfall totals through the end of the weekend do look to be pretty impressive across the region. An average of .80-1.10” looks like a pretty good bet across zones 6 and 7. However, I do think the areas that get under any thunderstorms could see 1.5-2” of new rainfall.
NEXT WEEK: Beyond the weekend into next workweek we will see an upper-level trough build in across the northeastern U.S. While I don’t think the weather will be as active as what it has been, I do think models are under playing the overall precipitation chances. The main reason for this is, we will be on a northwesterly flow through at least mid next week. Generally speaking, a northwesterly flow will result in disturbances moving through the area resulting in areas of light rain showers or scattered rain.
With the trough in place temperatures will likely be slightly below average across the region, at least to start the week.