Northern Illinois placed under a Winter Weather Advisory

Light snow overnight may make for additional slick spots this morning. However, a stronger system slated to move through this evening into tonight will bring a slightly higher chance for snow.

Earlier this morning, the National Weather Service placed all of our northern Illinois counties under a WINTER WEATHER ADVISORY. For Jo-Daviess, Stephenson, Whiteside, and Carroll County, this advisory will run from 6PM this evening until 9AM Friday. Winnebago, Boone, McHenry, Ogle, Lee, and DeKalb County will be under the advisory from 6PM this evening to noon Friday. 

Models show a scattered round of snow showers sliding in shortly after the evening commute, with chances remaining likely into early Friday. At times, snowfall rates could be as high as .5"/hr, which will in the end leave behind a swath of 1"-3" totals. 

The snow should taper off well ahead of the morning commute. However, traveling tomorrow morning will be rather tricky thanks to slick spots and the potential for blowing/drifting snow. 

Not only that, another piece of Arctic air looks to slither it's way into the Great Lakes behind tonight's strong cold front. Temperatures tonight and Friday will only land in the single-digits. 

Wind chill values by Friday morning will range from -10° to -15°, increasing the risk for hypothermia and frostbite if precautions aren't taken. Wind chill alerts will likely be issued as wind chill values will end up much lower Friday night into Saturday. 

Temperatures will fall below zero Friday night, and then again Saturday night as high pressure moves overhead. Thankfully, this bout with Arctic air won't be as prolonged as temperatures will make their way into the teens Sunday, then 30s early next week.
 

Wind chill advisory lingers, multiple snow chances to follow

A WIND CHILL ADVISORY remains in effect for the entire area until 9AM.

Wind chills up until then could fall to -25 degrees in some locations, allowing frostbite to occur on any exposed skin in a matter of 30 minutes. 

Be sure to dress in extra layers if you're heading out this morning. On a positive note, temperatures by this afternoon are expected to climb into the low to mid-teens with wind chill values finally warming above zero degrees by late afternoon! 

Two disturbances, one tonight and then one Thursday night, are then scheduled to bring the Stateline a chance for light snow showers. For most, snowfall accumulations will range from 1"-3", which may be enough for travel impacts for both Thursday and Friday morning's commute.

Also with the second disturbance will be a strong cold front, one of which will unfortunately bring an end to this "spike" in temperatures.

Winds behind the frontal passage will shift to the north and become stronger in the process. This will send high temperatures quickly back into the single-digits for Friday and Saturday, with overnight lows dropping back well below zero. 

It's likely we'll see another wind chill headline for late in the week as wind chills Friday night could fall as low as -30 degrees. Temperatures remain in the teens for Sunday afternoon, climbing into the low to mid 30s during the early stages of next week. One thing we'll have to keep an good eye on as temperatures warm is the potential for ice jams on our major rivers. This could lead to rapid fluctuations in river levels.

Patchy blowing snow continues Tuesday evening

 

Southwest winds were gusting at times to 30 mph Tuesday afternoon. This did cause some issues with blowing snow on north/south roads, especially in open and rural areas. Even some of the east/west roads experienced some patchy blowing snow.

The gusty winds will ease a little Tuesday night, but winds around 15-20 mph will keep the risk for at least some patchy blowing snow overnight. With the sun setting and temperatures falling, slick conditions will remain possible through early Wednesday. The threat for blowing snow will continue Wednesday with a west/southwest wind gusting around 20-25 mph during the afternoon.

Unlike this past weekend, significant blowing and drifting snow isn't anticipated due to some of the snow compacting down over the last few days, along with continued clearing measures. However, it may be just enough snow blown over the roads to cause some slick and icy spots through early Wednesday.  

Wind Chill Advisory remains in effect until Wednesday morning

 

High temperatures for some Tuesday afternoon warmed above zero degrees for the first time since this past weekend. Rockford's high made it to zero degrees, but that number has quickly fallen back below zero as of 5pm.

A WIND CHILL ADVISORY remains in place until Wednesday morning for all of northern Illinois and southern Wisconsin as wind chills will fall to -25 degrees in some locations. This means frostbite can occur on exposed skin in a matter of 30 minutes. Be sure to dress warm if you're heading out during that time.

The good news, temperatures Wednesday afternoon will warm into the low to mid-teens with wind chill readings finally warming above zero degrees by late afternoon! The 'warmup' won't last, however, as another strong cold front arrives Thursday will help drive afternoon temperatures Friday and Saturday back down into the single digits, and overnight lows back below zero. It's likely we'll see another wind chill headline for late in the week as wind chills Friday night could fall as low as -30 degrees.

Winds Tuesday have been a bit gusty from the southwest at times around 30 mph. This has led to some blowing snow on north/south roads, along with some drifting. As the sun sets Tuesday evening the winds should begin to ease some, but slick roads will be possible during that time. Continue to drive with caution as some blowing snow may continue to occur in open and rural areas through Wednesday morning. Wednesday afternoon winds won't be quite as strong, but we may continue to see some blowing snow.

Wind Chill Warning remains, more cold on the way

When the clock strikes 8AM, Rockford will be sitting below the 0-degree mark for 57 consecutive hours. Why is that significant? It's because this is the same amount of hours Rockford spent below zero during the polar vortex in January 2019. 

If you recall, Rockford broke it's all-time record low, registering a low of -31°. Now it goes without saying that air temperatures this time around haven't been as cold. But with the wind chill factored in, it has felt more like -30° to -35° at times. 

Wind chills that low will still be on the table for the first half of our Tuesday. 

That is why the National Weather Service continues to keep all of our northern Illinois counties under a WIND CHILL WARNING until 12PM. After the warning expires, a WIND CHILL ADVISORY will be in place area-wide, which will last through the overnight hours and into mid-morning Wednesday.

Wind chills values under the advisory could run as low as -20° to -25°. Again, make sure your doing as much as you can to keep yourselves, your loved ones, and your pets safe from the extreme cold. Especially during the morning hours today when the lowest wind chills will be felt. As a reminder, frostbite is possible within 10 minutes on any exposed skin.

If we don't hit or get above zero this afternoon, this multi-day stretch of sub-zero temperatures will come to a close Wednesday as highs peak in the low teens. From there, temperatures are to remain above 0° into Thursday morning and Thursday afternoon.  

Our next cold front is then scheduled to pass through late Thursday, bringing with it a chance for snow as well as another shot of bitterly cold air. Highs will be limited to the single-digits Friday and Saturday, with overnight lows falling well-below zero. Don't worry, improvements are on the way. Southwest flow returns Sunday, bringing high temperatures into the upper teens Sunday, then into the low 30s by Monday afternoon.

Northern Illinois remains under a Wind Chill Warning

Winter is in full swing across northern Illinois and southern Wisconsin. After the Rockford Airport saw it's highest snowfall since November of 2018, "high" temperatures Sunday only peaked at -3°.  

Why is that significant? That breaks the previous record cold high of -2° from 1994. Another record that is in jeopardy is our record low for January 15th as temperatures are currently sitting in between -12° to -20°. If Rockford were to touch or dip below -17°, that would tie or break the record. 

Lots of stats I know. But that just shows you the magnitude of this Arctic air mass. Now, a WIND CHILL WARNING remains in effect for all of our northern Illinois counties until 12PM Tuesday.

Wind chills values up both this morning and Tuesday morning will range from -25° to -35°.  So if have to be out and about either morning, do your best to adjust your schedule so that you can avoid being outside during the coldest part of the day.  

If you can't, layer up and cover as much exposed skin as possible. Frostbite in this type of extreme cold could occur in as few as 10 minutes. 

Once the wind chill warning expires, a WIND CHILL ADVISORY will take it's place. This will be for Green, Rock, and Walworth County in S. Wisconsin as well as Winnebago, Boone, McHenry, Ogle, Lee, and DeKalb County in N. Illinois. This will run from 12PM Tuesday to 9AM Wednesday morning.

Wind chills under the advisory will range from -15 to -30° Not only is it important to keep you and your loved ones safe from the cold, keeping your fur-babies in mind is also important.

Just like we say when we see the extreme heat spill in during the summer, pets are family too. Make sure to limit their time outdoors as well as making sure they have plenty of food and water.

Highs come Wednesday and Thursday will reach the lower teens, then drop back below 0 Thursday night as more Arctic air filters in. 

This will once again leave us in the single digits Friday and Saturday, with overnight lows falling well below-zero. Believe it or not, there is a light at the end of the tunnel as long-range outlooks from the Climate Prediction Center showcase above-average temperatures towards the end of January.  

  

What is considered above-average? 

We typically see temperatures heading back in the direction of the 30-degree mark.

Second winter storm is underway, dangerous travel expected

The second significant winter storm of the week is now well underway, producing snowfall rates between 1"-2" per hour. 

Difficult travel is likely during the morning commute. as roads are to quickly become wet and slushy. On top of that, the more intense snow bands will significantly drop visibility to a half mile or less, which we are already seeing in our southernmost locales.

2"-4" is possible with the first round. We then see a small window for a break from the more intense rates between late-morning and early afternoon. It's also during this time in which we could see the rain/snow mix line lift northward into N. Illinois. 

When it came to dissecting this winter storm, that was the biggest question mark, how far north into Illinois does the rain/snow mix line end up. 

For the most part, forecast models this morning keep the 32° line near or south of I-88. This would allow precipitation to remain all snow for spots along and north of the interstate. Even if we do see a chance for a light mix into the afternoon, the expectation is for precipitation to change back to all snow by mid-afternoon. From there, snow will continue to be the main type of precipitation, this time in a drier and fluffier state thanks to rapid cooling taking place in the atmosphere.

Tagging along with the fluffier snow will be an uptick in winds, which will gust up to 35-45mph during the evening and overnight. 

That will allow blowing and drifting snow to become a major concern, which may create near-whiteout conditions over a very large swath of our viewing area. Travel Friday evening into Saturday morning will be quite dangerous, if not impossible.

It’s strongly recommended that folks stay home if at all possible. This event overall will come to a close around mid-morning Saturday, leaving behind a swath of 6"-10", with isolated higher totals possible. The threat for blowing and drifting snow as well as wind-driven snow showers continue, allowing impacts to travel to extend into Saturday afternoon. On the backside of this very dynamic storm system, a rather strong northwesterly wind will help Arctic air spill into the Great Lakes. 

To take in account for the wind chills, the National Weather Service has placed Jo-Daviess, Stephenson Carroll, and Whiteside County under a Wind Chill Watch.

This will be from Saturday evening into Tuesday morning.