Temperatures are falling much faster than the last few nights, with overnight lows that will reach down in the low 60s. Under a lighter wind, a few patches of fog will be possible, with some pockets of locally dense fog in low-lying areas.
Tonight is just the start of a few cooler nights, with overnight lows in the upper 50s to low 60s. Much more comfortable air will be with us through the holiday weekend, as dew points remain below the 70-degree mark until Tuesday. Patches of fog will be possible at least Saturday and Sunday nights with high pressure and a lighter wind overhead.
After Friday recorded a 4th straight day in the 90s to kick off September, the holiday weekend will not be quite as hot. The main reason for this will be the decreased humidity. High pressure will spread across the Great Lakes region, working to push the humid air mass back West again for a few days. This will send dew points down into the 60s, a much more comfortable feel than the mid and upper 70s from earlier in the week.
That will result in a much more pleasant, but still warm, forecast for this Labor Day weekend. Air temperatures may still push into the mid-80s Saturday, but lower 80s on the way for Sunday and Monday. Overnights are even more reflective of the less humid air, with lows in the 60s most nights! The lighter wind amid high pressure may result in a few nights of patchy fog, though. Lacking more sufficient moisture and upper-level dynamics, we will remain dry through at least Monday.
[11PM] The bulk of our thunderstorms have now pushed well off to the East, resulting in drier conditions locally. While an isolated shower or storm remains possible into the night, most will stay dry. Humidity does not go anywhere, with temperatures only dropping into the low 70s. Patches of fog may be possible early Saturday morning.
[8:55PM] The storm has lost a bit of its strength but may still produce a quick burst of heavy rain and a strike or two of lightning as it moves overhead. Motion is still to the Southeast at around 30 mph.
[8:35PM] There have been a few more lightning strikes on this cell near Durand/Pecatonica in just the last few minutes. Storm is moving Southeast at around 20-30 mph, which could put it near the NW side of Rockford around 9PM if it holds together.
[8:30PM] A couple of isolated showers have developed near the Stateline. One moving into Northern Winnebago County that recently produced a lightning strike near Durand, and another in Western McHenry County. Both cells are moving Southeast at 20-30 mph.
[7PM] Thunderstorms have struggled to maintain themselves into the Stateline, with only a few stray showers surviving into Jo Daviess County. The clouds will continue to push across the area, with an isolated rumble of thunder possible from time to time, but most will stay dry this evening.
It will be another hot and humid evening with isolated storm chances! As of 4:30PM, many locations are seeing temperatures in the 90s with heat index making it feel like the triple digits. Isolated storms have begun developing to the Northwest, but are only moving at 20 mph.
If those storms maintain their strength, they might approach the Stateline after 6PM. Highest storm coverage may remain North of Rockford, but we will maintain a 20% chance through the late evening.
Either way, it will be rather humid start for those Friday night football games, whether they start at 7PM or are delayed to 8PM. Temperatures will remain in the 80s through at least 9PM where storms do not cool things down. Isolated storms remain possible through this time, but highest coverage will remain mainly North of the Stateline.
Heat and humidity will unfortunately stick around for another day here across the state line with the 4th day in a row of 90° temperatures on tap. Dewpoints won't offer any relief either as temperatures will be in the low 70's which will send heat advisories near and above 100° once again today. Because of this, heat advisories are in effect through 10pm this evening so make sure to continue to practice heat safety once again.
Thankfully, some relief does look likely into the weekend thanks to a higher-pressure system that's expected to move in by Saturday. This high pressure will be making its way out of Canada so as it makes its way south, drier and cooler conditions from the north will be dragged down to the Great Lakes region.
Temperatures over the weekend will drop below the 90° mark however we'll still be above average with temperatures each day. Either way, conditions should become more comfortable through the weekend thanks the higher pressure which should offer great conditions for Labor Day Festivities!
It's been a sizzling start to September across northern Illinois and southern Wisconsin, with summer refusing to loosen it's grip. Tuesday brought one of the hottest days of the year so far, as Rockford soared to 96 degrees under strong sunshine and a persistent southwesterly wind. Adding to the discomfort, both September 1st and September 2nd featured peak heat index values above 100 degrees.
3rd Heat Advisory:
With the heat continuing, a third heat advisory has been issued for all of our northern Illinois counties. Unlike the previous two advisories, this one is abit longer-lived, having gone into effect this morning and remaining in placeuntil 9PM this evening.
Toasty Thursday:
Afternoon temperatures will once again climb into the upper 80s and low 90s, while humidity levels push heat index values into the 100to 105 range. With another day with dangerous heat expected, make sure heat safety remains a HUGE priority. If you'll be spending an extended time outdoors, be sure to stay hydrated, drink of water, and take frequent breaks in the shade or air conditioning.
Now, the one thing that could "spare" us from the heat would be thunderstorm chances which we have this morning and then again this evening into tonight. Like yesterday however, the jet is oriented in a way where the highest potential is displaced to our north across portions of Wisconsin, hence the level 2 Slight Risk for scattered strong storms. Roughly two-thirds of southern Wisconsin and most of northern Illinois are under a level 1 of 5 Marginal Risk for severe weather, indicating that any threat for stronger storms locally will be more isolated in nature.
The early September heat has really packed a punch, with two days each reaching into the mid-90s! That heat will fuel the potential for at least some isolated thunderstorms in the coming days, beginning Wednesday evening and overnight. While most will remain dry, a stray shower or storm may be possible from time to time. Outside of storms, it will remain very warm and humid, with overnight lows only dropping into the mid-70s.
Much of the daytime Thursday will once again be dry, hot, and humid. Afternoon temperatures will likely surge into upper 80s and low 90s for some. Isolated storms may be possible during the afternoon and evening, with highest coverage across Southern Wisconsin. Where it doesn't rain, heat index values will likely push into the triple digits again.
Any other chances for storms will depend on placement and evolution of previous rounds, but higher coverage looks possible Thursday night into Friday. There will be a fair bit of dry time in between rounds, but periodic thunderstorms are possible into the holiday weekend.
Future-cast has the Thursday night round mainly North and Northeast again, but the ingredients for a couple storms will be in place for much of the area. A few stronger storms may be possible, with a low-end risk for severe weather. Strongest storms may be able to produce damaging wind gusts and large hail, as the Storm Prediction Center maintains a Level 1/5 Marginal risk overhead for Thursday into Friday morning.
Showers and storms may be ongoing Friday morning and could persist into the daytime. If storms track over the same regions as the couple nights before, flash flooding may be a larger issue. If showers linger into the afternoon, temperature could be limited to the upper 80s Friday. But if things dry out quicker, another 90-degree day is on the table.
Temperatures climbed to 94 degrees in Rockford on Tuesday, making it the hottest day of the year so far, and while today's high temperatures may end up a degree or two lower, oppressive humidity will keep conditions feeling much hotter.
A heat advisory will once again be in place for all of northern Illinoisfrom 12PM-9PM. Heat indices are expected to reach between 100° and 105°, possibly as high as 110° this afternoon, creating dangerous conditions for anyone spending time outdoors. Like yesterday, be sure to stay hydrated, take frequent breaks in the shade or air conditioning, and remember that little relief from the heat is expected overnight as temperatures only fall into the low 70s.
