Short and long range video forecast. M.
EVENING – TONIGHT: Mostly sunny to partly cloudy skies will continue as an area of high pressure remains in place across the region.
Overnight clear to mostly clear skies look to remain with perhaps some high clouds in place, especially south, as a storm system moves well south of the region.
Lows overnight will be in the mid 20’s north to mid 30’s south across zones 6 and 7.
TUESDAY: Through the daytime hours clouds will start to thicken up from southwest to northeast. This will be as an area of low pressure starts to get itself together across eastern Texas and Louisiana, then head north and northeast.
While most of the day looks to be dry, a few on and off showers will be possible through the day. These look to be mainly from I-70 southward across Illinois.
Highs on Tuesday will be in the mid 40’s north to mid 50’s to the south. Winds on Tuesday will be from the northeast at 5-15 mph, with some gusts of 20 mph or so possible.
Tuesday evening the better concentration of rain will move into southern zone 6. This looks to occur around 7-8 PM, then spread to the north into the overnight.
By 12 – 1 AM Wednesday rain looks to be in place from I-70 southward across Illinois.
Rain will continue working northward across zones 6 and 7 through the overnight into Wednesday morning. By the time we get to 6-8 AM some rain may be changing over to snow across western and northwestern zone 7.
Overnight lows Tuesday will be in the mid 30’s north to mid 40’s south.
WEDNESDAY – THURSDAY: Through mid-day Wednesday the low will track northeast along the Ohio River area. As it does cold air will start to move into the forecast area transitioning rain to snow across north and northwestern portions of zone 7 and then into zone 6.
Through the afternoon Wednesday winds will also start to pick up as the area of low pressure moves close to the forecast area. Sustained winds of 15-25 mph are likely with wind gusts of 35-45 mph. A few models even suggest wind gusts of 50-55 mph aren’t out of the question.
Highs on Wednesday will be in the 30’s.
Regarding rainfall totals, models seem to be in agreement that southern and southeastern Illinois could see a pretty good helping of rainfall. Many models suggest around 2” of new rainfall with even a few suggesting 2.5-3”. If this were to verify flooding could become a problem there.
Through the afternoon the transition from rain to all snow will continue. Current model guidance suggests the rain/snow transition is complete by 4-5 PM. At this point snow will be falling across zones 6 and 7, some of which will be coming down at a pretty good clip!
Through the evening snow will still be likely, but there may be a bit of a lull in activity from 9 PM and 2 AM.
However, another upper level impulse will start to move into the forecast area. This will allow for at least some periods of snow through the overnight hours Wednesday into Thursday.
Lows will be in the mid 20’s to low 30’s. Winds looks to remain strong with gusts of 35-45 mph possible.
Through the daytime hours on Thursday some times of snow will be possible from I-70 north. However, farther south temperatures may be warm enough to support rain.
Highs on Thursday will be in the upper 20’s to mid 30’s. Winds will remain strong with gusts up to 35 mph possible.
Late Thursday the low and upper level energy will move off and the snow looks to come to an end.
Models currently place the main swath of snow across central Illinois then into northern portions of Indiana. Many models show 2-5” of snow being a good bet across portions of zone 6 and 7. However, the GFS and NAM 4 km are a bit more aggressive with areas of 6-8” possible.
This forecast is nowhere near written in stone just yet. I wouldn’t be shocked to see these snowfall totals shift to the south and east over the next several runs taking portions of the zones out of the area of accumulating snowfall. There are a few reasons I think this.
The first being you rarely see an area of low pressure track along the Ohio River and into the Cincy area and the heavy snow swath be across Illinois and north/northwest Indiana.
The other is models have had a northwest bias all year and many times have corrected southeast at the last-minute.
Finally these low pressure systems like to generate their own cold air, it’s a meteorological phenomenon called dynamic cooling. This in itself would allow temperatures to cool enough to change rain to snow. Therefore resulting in more accumulations and possibly more of a widespread snow event.
Here are our preliminary thoughts of where the most probable place for 6+” of snow will be with this storm.
Regardless, it is a forecast we will be watching very closely over the next 24+ hours for any changes.
7 DAY FORECAST
TUESDAY: INCREASING CLOUDS FROM SOUTH TO NORTH. PERHAPS A FEW SHOWERS SOUTH LATE IN THE DAY. HIGHS IN THE MID 40’S NORTH TO MID 50’S SOUTH. NORTHEASTERLY WINDS 5-15 MPH, GUSTING TO 20 MPH.
TUESDAY NIGHT: CLOUDY WITH RAIN, PERHAPS A BRIEF MIX IN FAR NORTH ZONE 1. LOWS IN THE MID 30’S NORTH TO MID 40’S SOUTH.
WEDNESDAY: CLOUDY, RAIN IN THE MORNING CHANGING TO SNOW IN THE AFTERNOON, SOME HEAVY SNOW POSSIBLE. HIGHS IN THE LOW TO MID 30’S WITH UPPER 30’S TO LOW 40’S SOUTHEAST. SNOW ACCUMULATIONS LIKELY. NORTHERLY WINDS AT 10-25 MPH, GUSTING TO 40 MPH.
WEDNESDAY NIGHT: CLOUDY WITH SNOW, SOME COULD BE HEAVY. LOWS IN THE MID 20’S NORTH TO LOW 30’S SOUTH. SNOW ACCUMULATIONS LIKELY.
THURSDAY: SNOW SHOWERS REMAIN EARLY, THEN END LATE. HIGHS IN THE UPPER 20’S TO MID 30’S. NORTHWEST WINDS AT 10-20 MPH, GUSTING TO 35 MPH.
THURSDAY NIGHT: SNOW ENDS, OTHERWISE PARTLY CLOUDY AND COLD. LOWS IN THE MID TEENS TO UPPER 20’S.
FRIDAY: PARTLY TO MOSTLY CLOUDY. HIGHS AROUND 30 NORTH TO AROUND 40 SOUTH.
FRIDAY NIGHT: MOSTLY CLOUDY WITH A FEW SNOW SHOWERS. LOWS IN THE LOW 20’S TO LOW 30’S.
SATURDAY: MOSTLY SUNNY WITH HIGHS IN THE MID 30’S NORTH TO LOW 50’S SOUTH.
SATURDAY NIGHT: MOSTLY CLEAR WITH LOWS IN THE UPPER 20’S TO UPPER 30’S.
SUNDAY: PARTLY CLOUDY, HIGHS IN THE MID 30’S TO UPPER 40’S.
SUNDAY NIGHT: MOSTLY CLOUDY WITH A CHANCE OF RAIN AND/OR SNOW. LOWS IN THE UPPER 20’S TO MID 30’S.
MONDAY: MOSTLY CLOUDY, RAIN TO SNOW? HIGHS IN THE LOW 30’S TO LOW 40’S.
MONDAY NIGHT: MOSTLY CLOUDY WITH A FEW SNOW SHOWERS? LOWS IN THE UPPER TEENS TO AROUND 30.