Big temperature swings ahead for northern Illinois

Weekend Comparison:

"False spring" has unfortunately come to a close as afternoon highs this past weekend ended up MUCH cooler than the previous weekend.  

Highs at the Rockford Airport went from low 50s and low 60s back to January standards. 

 

Ups & Downs: 

Today, still January-like. The day even begins with wind chill values near or below zero. So make sure to pack those layers this morning. 

High pressure close by will give us plenty of sunshine from start to finish. However, we hang on to a rather cold wind out of the northwest. This will once again leave highs in the upper 20s while also leaving wind chills in the teens this afternoon.  

We'll see winds take a turn to the southwest Tuesday ahead of an approaching cold front. Gusts across the region may reach 35 to 40 mph, helping to boost high temperatures near the 40° mark. 

 With the cold front as well will come the chance for a rain/snow mix or a few snow showers. Chances will be highest late in the afternoon into the evening with skies clearing up some Tuesday night. Overnight lows will end up in the upper teens tonight, then possibly again into Wednesday morning. 

Behind Tuesday's frontal passage, winds shift to the north and northwest for Wednesday, limiting highs to the low 30s and then mid 30s for Thursday. The warmest air is scheduled to arrive Friday as winds turn back to the southwest, boosting temperatures into the upper 40s, close to the 50° mark. 

Subzero wind chills possible Monday morning, sunshine by afternoon

 It will be another cold and breezy night with North winds around 10-20 mph through the night. Clouds will thin out a bit after midnight, dropping temperatures into the low/mid teens. Wind chills will drop toward zero for most of the night.

Tomorrow will see winds ease up a bit through the evening as high pressure moves over the area. It will feel much warmer with that lighter wind by the afternoon and more sunshine, but high temperatures will remain in the 20s for the third straight day. Wind chills will still make it feel like the teens nearly all day.

High pressure keeps us dry through Monday night, but another passing clipper system will bring a narrow window for some snow showers or light wintry mix. This will develop along a cold front early Tuesday afternoon, with the bulk of the precipitation falling across Wisconsin. This also comes with another round of strong winds but from the Southwest this time. High temperatures will reach near 40 degrees on Tuesday.

A more widespread chance for precipitation arrives mid-week with a broader chance for snow locally. There is still a lot of time for this system to change course, but additional snow showers may be possible starting Wednesday night into Thursday.

Chilly start to the week, pattern then switches into the middle of the week

 

With yet another cool and blustery day passing yesterday we unfortunately don't look to change much in terms of our surface conditions today. Temperatures this afternoon will be even cooler than the previous days as we'll be in the mid 20's while wind gusts will reach up to 30 mph. This will keep temperatures feeling quite chilly today as wind chill values will stay in the single digits most of the day.

Not much relief will be expected tomorrow either as high pressure overhead will keep us cool, but thankfully calmer in terms of wind speeds. Heading into the middle of the week though temperatures will begin to rise as a few systems begin to move nearby. This will not only increase our precipitation chances but will also transport slightly "warmer" temperatures into the region.

As the pattern switches into the middle of the week, we'll be monitoring two separate systems. The first on Tuesday will be a low-pressure system tracking mainly to our north, however along the cold front of the system a few snow showers and possible mixed precipitation may occur Tuesday night into Wednesday morning.

Into terms of the system on Thursday, confidence has risen over the past 24 hours of a stronger system impacting portions of the lower Great Lakes region. As of now, the low-pressure system looks to track to our south which in that case would allow for cooler temperatures locally and higher chances for snowfall.

If this were the case, snowfall accumulation would be likely and looks to be the case as of now. Although we're too far out to forecast total snowfall, the chance for at least accumulating snowfall looks likely with this system as we head into late Wednesday and into Thursday. 

Cold winds stick around into next week

 Unfortunately, the unseasonable warmth from last week is long gone as the afternoon high Saturday afternoon only made it back into the 20s with a cold Westerly breeze. Stronger winds will be possible Sunday as a strong arctic high pressure develops across the Northern Plains. We will be sandwiched between that high pressure and an equally strong low pressure developing off the East Coast.

That difference in pressure, or pressure gradient, will funnel Northwesterly winds our direction Sunday with gusts approaching 25-35 mph at times. Monday will see winds ease up a bit to 15-25 mph gusts from the North with higher pressure moving overhead. Tuesday flips the wind direction around to the Southwest with a passing weather system.

Northerly winds Sunday and Monday will again keep temperatures suppressed in the 20s. A Southwest Wind brings near 40° highs back for Tuesday and Wednesday before another drop mid-week.

A few passing flurries may try to fly from time-to-time Saturday night into Sunday morning, but higher chances for precipitation arrive Tuesday with a passing clipper system. That will develop a chance for rain and snow showers along the passing cold front that afternoon. Another chance for snow may arrive Wednesday night into Thursday with another low pressure system, but there are still many potential scenarios that could play out with this system.

Temperatures remain below average into early next week

 

I hope everyone hung onto their hats yesterday! After a very chilly end to the week thanks to gusty winds up to 45 mph yesterday, we look to stick with a cooler trend into the weekend and into early next week. That starts today as temperatures will reach near or just above freezing today as cloud cover will keep us from seeing warmer temperatures. Although not as breezy as yesterday, winds will still gust up to 25 mph this afternoon.

Breezy conditions will continue into this evening as temperatures drop which will bring in some of the coolest feeling air in the last two weeks as wind chill temperatures look to drop near or slightly below 0 across the state line tonight. Along with that, a weak upper-level disturbance will also bring the chances of a few scattered flurries however accumulation totals will remain near zero.

As we continue into the weekend cooler air behind a low-pressure system to our east will continue to keep us cooler and will even keep us under 30° both Sunday and Monday. Thankfully though as we go into Tuesday temperatures will rise back above average as our next upper-level wave approaches.
 

 

Chilly weekend ahead with a few spotty snow flurries

 It was a big shock to the system with the cold wind Friday afternoon as afternoon temperatures only rebounded to the mid-30s. Officially, Friday's high will go down as 41 degrees, but that was reached not long after midnight.

This weekend will be far cooler than recent temperature trends with afternoon highs near or below freezing. We will keep the breeze and cloud cover around, likely preventing temperatures from reaching 30° Sunday afternoon. Wind chills will make it feel closer to the low 20s Saturday afternoon, and teens or cooler for Sunday.

A few weaker systems will pass through over the weekend, bringing a slim chance for flurries from time to time. The best window will be Saturday night into early Sunday morning. Any snow that does come down will likely not accumulate locally but could cause a few slick spots. Sunday afternoon will end up dry, but mostly cloudy and windy.

Wind gusts could push 25 mph from the West-Northwest on Saturday, and nearly 30 mph from the Northwest Sunday. Winds will ease Sunday night into Monday as high pressure takes hold, but the cold breeze will stick with us this weekend. Wind chills may feel as low as the single digits, particularly Saturday night into early Sunday.

Wind advisory in place across northern Illinois as snow pushes through

Friday Morning Snow: 

Snow associated with the same low pressure system that produced Thursday evening's rain will rotate into the area as the morning goes on. Some of these snow showers will be heavier than other, with the highest coverage northwest of Rockford.

  

Wind Advisory:

Pavement temperatures will still be too warm for icy spots to develop. However, a WIND ADVISORY  will go into effect area-wide around the start of this morning's commute. This mean we'll be contending with strong westerly winds at the same time the snow showers are pivoting through the region. These conditions may lead to wind-whipped snow showers and occasional fluctuations in visibility. The advisory is set to last until 4PM this afternoon.  

Weekend Forecast: 

Cloud cover and a decent breeze stick around for the upcoming weekend. With this cloud cover may come the chance for a scattered flurry or two. Otherwise, expect temperatures to drop below average, landing in the upper 20s by Sunday afternoon. 
 

 

Wind-whipped snow showers Friday morning

 Summer turns to winter overnight as rain flips over to snow by Friday morning. We will see a lull in precipitation after 12AM as the low-pressure system passes directly overhead. This will result in some light drizzle as temperatures remain in the 40s through 3-4AM for most.

After 4AM, the low pressure will continue to slide out of the area, flipping things over to a mix or snow by early Friday morning. Some of these snow showers may be steady to heavy at times, with the highest coverage Northwest of Rockford. Snow will begin winding down after 12PM, eventually drying out by the afternoon.

Steadiest snow will remain mostly North and West of Rockford, where a few spots in Southwestern Wisconsin and far Northwestern Illinois may be able to pick up a couple inches of slushy accumulation mostly on grassy and elevated surfaces. A winter weather advisory is in place for Green County in Wisconsin and Jo Daviess County in Illinois through the early afternoon.

These snow showers will come with a strong wind. West/Northwest gusts may approach 45 mph at times Friday morning into the early afternoon. Any snow coming down during this time will significantly limit visibility and allow for some blowing and drifting concerns. A wind advisory will go into effect across all of Northern Illinois at 6AM and through the afternoon.

Isolated severe storms possible across northern Illinois Thursday

Storm Chances Return:

Apart from Wednesday's notably strong southwesterly wind, the combination of sunshine and 60° warmth made for another gorgeous afternoon.  

As we move into Thursday, this is when we enter a slightly more active and cooler weather pattern. Most of the day Thursday will be dry, though we can expect clouds to increase early on. With the current track of our next low pressure system, surface flow will be out of the northeast, resulting in cooler high temperatures. Most locales will peak in the low to mid 50s. Still mild, but not as warm as yesterday. 

In their latest round of outlooks, the Storm Prediction Center places the highest severe potential well south of the Stateline area. Areas east of St. Louis are under a level 2 Slight Risk for severe storms. 

It's in these areas where the warm front will be the focal point for strong to severe storms, allowing all hazards to be on the table. Atmospheric energy will be higher as well as moisture levels. Locally, a level 1 Marginal Risk is in place for areas like Sterling, Dixon, Rochelle, DeKalb, and Amboy. 

Precipitation Timing: 

Shower and storm chances locally will be tied to the surface low itself and should begin to increase late in the afternoon into the evening. The biggest concern with any severe storm will be large hail. 

As colder air wraps around the surface low, rain will turn to the rain/snow mix and then to all wet snow by the time we get into Friday morning. Given the warm past few days, Thursday's rain, and temperatures still only in the low 30s, accumulations will be kept to a minimum (maybe up to a half-inch). Friday's morning commute may be a bit slow with lingering snow showers and reduced visibility with winds picking up.

Cooler Moving Forward:  

After today, it's back to reality as afternoon highs return to the 30s. Mid to upper 30s into the weekend with low 30s into early next week. 

Winter-like chill returns in full force this weekend

 Each of the last 6 days has featured high temperatures well above average and even well into the 50s or 60s! Most of February has featured the milder pattern, including the last several days more than 20 degrees above average!

But all good things come to an end, as cooler air will filter back in by the weekend in a sharp reminder that it is still February. Afternoon highs will return back toward the 30s and much closer to average by the weekend, as a large pocket of colder air will settle overhead through much of next week.

As high pressure takes over Sunday, winds may be strong resulting in a wind chill factor. The coldest days in the near term will be Sunday and Monday with coldest air centered overhead. The wind direction most days will be generally out of the North, helping to keep us cooler.

We will gradually warm back up a bit toward the middle of next week as the next broad low-pressure system arrives between Tuesday and Wednesday. This could bring us a potential for more rain and storms, or snow showers depending on which side of the weather system we end up on. For now, a broader area of precipitation appears likely Tuesday night into Wednesday, with another drop in temperatures expected behind this system.

Strong winds slowly subside Wednesday evening

 The strong winds we've experienced throughout much of the afternoon will begin to subside as we approach sunset, turning much lighter later this evening. Until then, a Wind Advisory remains in effect until 6pm for all of northern Illinois as winds are still gusting around 35 mph in some locations. At the same time, the Red Flag Warning remains in effect until 8pm as relative humidity values have fallen under 20 percent in many locations.

Strong low pressure to the north near the Wisconsin/Minnesota state line has been responsible for the winds this afternoon. But as the sun sets and we lose the mixing of the afternoon (stronger winds pulled down from aloft), winds will ease as low pressure weakens and pulls further to the north.

Clouds will be on the increase through the night as the next low moves in, moving towards Missouri and northern Illinois Thursday. This will bring us our next chance for showers and even a few thunderstorms during the afternoon and evening.

Red Flag Warning in place across northern Illinois

Red Flag Warning: 

Yesterday's wildfires across Oklahoma demonstrated how easily dry, warm, and windy conditions can fuel their spread. Because today's weather conditions will be somewhat similar, the National Weather Service has placed all of northern Illinois under a RED FLAG WARNING from 10AM-8PM. 

  

Along with the Red Flag Warning, Winnebago, Ogle, Carroll, Stephenson, and Jo-Daviess Counties as well as Green County in southern Wisconsin will be under a WIND ADVISORY. This will also begin at 10AM and last until 6PM this evening.  

 

  

Timing of Strongest Winds:

Once the cold front passes through, skies clear rather quick, allowing sunshine to return. But the trade-off is wind, a gusty westerly wind that could top out around 40, possibly 45 mph at times. The strongest winds are expected to arrive late this morning and last through much of the afternoon. And typically, a westerly to southwesterly wind promotes a drier air mass, causing relative humidity values to fall below 25%. 

The combination of the very warm temperatures, dry conditions, and gusty winds will allow any fire that develops to spread quickly. 

So please, avoid outdoor burning today. You can also help prevent wildfires by clearing any brush or leaves, disposing of smoking products safely, and double-checking towing chains and tires. Winds will weaken as we head into this evening, remaining light out of the southeast overnight into Thursday.     

A few storms possible Thursday afternoon and evening

 

While it's nothing set in stone just yet, there is a risk for a few thunderstorms in northern Illinois late Thursday afternoon and evening. The higher risk remains just to our south downstate across central Illinois and Indiana. But a few isolated stronger storms could approach our southern counties by Thursday evening.

Showers moving in Tuesday evening will remain light, but a rumble of thunder or two after Midnight is possible as both low pressure and a cold front approach from the west. The low will lift to our northwest, holding temperatures close to 50 degrees overnight! This will help springboard us into the low 60s Wednesday afternoon.

A second system will approach northern Illinois and southern Wisconsin from the southwest Thursday, drawing yet another warm front north into the Stateline during the afternoon and evening. How far the front lifts north will determine just how warm our temperatures get for the afternoon, but I think it'll come close enough to at least get us back into the upper 50s, if not at 60 degrees. A few isolated showers/thunderstorms could develop as early as the afternoon along the warm front, but a cold front moving across west-central Illinois will likely fire off more scattered thunderstorm activity towards Thursday evening.

The Storm Prediction Center has most of central and east-central Illinois and Indiana highlighted under a 'Slight' risk which means scattered strong to severe storms are possible, while a 'Marginal' risk extends up near I-88 in northern Illinois as a few isolated strong to severe storms are possible. But the coverage of any storm activity this far north will depend on just how far north the warm front makes it, and if we end up within the system's narrow 'warm sector'. If that remains to our south, then the chance for thunderstorms will remain south as well. But if even a small portion of the warm sector moves into northern Illinois, then at least part of the region could be dealing with an isolated strong storm or two.

Early season storm set-ups can be a little tricky as even just a change or two in temperature or dew point can mean the difference in storms or no storms. So, as we approach Thursday just make sure you remain weather aware and updated on the forecast.