Meteorologist Taylor McCann

Latest and greatest from NWS. If you have outdoor plans for Father’s Day, it would be wise to move them indoors with heavy rain and localized flooding expected tomorrow. Conditions will improve heading into the work week with sunny skies and seasonably cool temperatures solidly in the 70s.

Steady rain is expected to move in tomorrow with the potential for localized flooding, particularly south of Interstate 80. Cooler below normal temperatures are expected through the week with another chance for storms midweek.

In the midst of all the severe weather, I want to say thank you for 200 followers. I hope this is a page you can rely on for accurate forecasting and (sometimes) instructions to keep you and your families safe.

8:15 PM CDT UPDATE

It looks like most of the Chicagoland area has been spared as far as severe weather goes. Showers and thunderstorms have failed to develop along the cold front, so a drop in temperature and brief gusty winds (25-30 MPH) is what we can expect later this evening.

Tomorrow will be windy as this anomalously strong low exits the Great Lakes region with temperatures in the low-to-mid-70s. Cloud cover will decrease as the day progresses and deep-level moisture treks east. Friday and Saturday will be uneventful - partly cloudy skies and a subtle warming trend topping off near 80°F on Saturday.

Our next chance for meaningful precipitation will arrive on Sunday and linger into Monday morning. Medium-range guidance has been trending south for the bulk of shower and thunderstorm activity, but there is still plenty of time for this forecast to chance.

Temperatures will be unseasonably cool heading into the beginning of next week, and this would be a great time to open the windows for some fresh air and give your AC a break.

‼️‼️NO LONGER VALID‼️‼️

5:00 PM CDT UPDATE:

SPC has moved the moderate and enhanced a bit further south than this morning’s outlook. The greatest risk for strong severe weather lies within that outlook area (including large hail and some long-track tornadoes), but we are not out of the woods up north in Chicagoland.

Things may get interesting in a few hours north of I-80. While we are in a semi-favorable environment for thunderstorm development (ample moisture, wind shear), the instability does not look like it will fully materialize. However, the clearing that we have seen over the last hour or so will help destabilize the atmosphere. In addition, some gravity waves* have developed in northern IL.

Later this evening, a line of strong thunderstorms will move through with cold frontal passage. Storms may not meet the severe threshold, but we can still expect gusty winds and heavy downpours.

*Gravity waves:
Gravity waves form when warm, moist air rises into a stable environment. There is natural tendency for this same air to sink, thus forming a wave pattern in the sky. Gravity waves can aid in thunderstorm development, so this should not be taken lightly.

‼️‼️NO LONGER VALID‼️‼️

1:30 PM CDT UPDATE:

A notable change in SPC’s outlook puts Chicagoland in a slight risk (2 of 5) rather than bordering the moderate (4/5). This morning’s rainfall has continued into the afternoon, and it does not look like we will get the clearing that is needed to destabilize the atmosphere.

Additionally, the warm front has stalled along the I-74 corridor, and we will likely remain well north of this boundary with cooler temperatures and stratiform rain. While we’re not completely out of the woods, the overall risk for severe weather Chicagoland has decreased.

Central IL is a different story. All hazards remain possible, and if you are located in central IL, please heed all warnings that are issued for the second round later this afternoon and evening. This low pressure system is much stronger than we would normally see for June, so prepare for damaging winds, large hail, and strong, long-lived tornadoes.

Good morning everyone.

A severe weather outbreak is likely later this afternoon in the highlighted areas. All modes of severe weather are possible.

The million dollar question is how far north the warm front will go. Recent model guidance suggests a more northward extent than initially anticipated, and if there is enough clearing after this morning’s activity, we may see some discrete supercells before activity associated with the cold front.

Latest and greatest from NWS. Tomorrow’s severe weather is going to be intense. Upper-level support, mid-level parameters, and the associated surface low are all much stronger than what we would typically see in June. Right now, central IL will likely bear the brunt of this, but severe weather can and will occur outside of the moderate risk currently in place.

Will have an update tomorrow morning to see how tonight’s convection will affect the surface environment tomorrow morning.

Good evening everyone. It is going to turn into a busy week weather wise, so let’s dive in.

Tuesday will feature a slight chance of afternoon thunderstorms with a very small severe threat. The strongest storms will be located east of I-39 with isolated damaging winds. There is not much forcing* for organized complexes, but Wednesday will be a different story.

There may be some lingering convection in the morning depending on what happens Tuesday evening, and damaging winds will be the main threat in northern IL. The warm front associated with the surface low looks to remain south of NWS Chicago’s jurisdiction at the moment, which is where supercells will potentially develop. The low pressure system will deepen rapidly as the day progresses, and with strong wind shear in place there is an increased threat for large hail, destructive winds, and a few tornadoes to our south.

While the fine details remain uncertain, particularly the northward extent of the warm front, we will likely see a strong and organized complex of severe storms develop later in the day along the system’s cold front. All modes of severe weather possible.

In addition to severe weather on Wednesday, deep-layer moisture will support heavy downpours within thunderstorms. This will lead to flash flooding in both low-lying areas and on the street level. Ponding in parking lots is another thing to watch out for. If you come across a flooded road or see major puddles, turn around, don’t drown! It does not take much to float a car, and you never know how deep the water actually is.

Temperatures will hold steady in the upper-70s this week even with frontal passage Wednesday night. Breezy conditions will linger for the rest of the week with bountiful sunshine.

Good afternoon everyone!

We finally have some quieter weather on tap after a cold front moves through overnight. There’s a very small chance for some thunderstorms, but coverage will be scattered at best. Storms will be accompanied by heavy downpours, gusty winds, and frequent lightning.

Tomorrow will be much cooler than what we’ve experienced this past week with highs in the low-70s. Conditions will be breezy as the low pressure system continues its eastward trek, and this will lead to dangerous beach conditions. If you decide to head to the Lake Michigan shore, please use extreme caution if you decide to go into the water. Waves will be highest along the IN shoreline, and if you want to dip your feet in the water, do not go above your knees. It won’t take much to knock you off your feet, and rip currents can be deadly. Cloud cover will decrease throughout the day and Monday will be very pleasant - mostly sunny skies with high temperatures in the mid-to-upper-70s.

Unfortunately the quiet pattern will not last long with thunderstorm chances increasing mid-week. SPC has northern IL outlooked for Day Five, which is Wednesday. The greatest threat will likely be south of I-80, but there is still plenty of time for this forecast to change. Models should have a better handle on this potential multi-day event come early next week.

As far as temperatures go, there will be a slight warming trend as the week progresses. Daytime highs will warm into the upper-70s and top off at the 80°F mark. Hopefully this gives your AC system a little break after the 90s we saw last week.

9:15 PM CDT UPDATE:

The tornado watch has been allowed to expire in all of northern IL. Temperatures will be a little cooler tomorrow after a cold front moves through overnight. Our next chance at meaningful precipitation will be Saturday night accompanied by a more potent secondary front, dropping temperatures into the low-70s by Sunday.

And a pretty sunset? Not a bad way to end the day.