Rain and snow possible Saturday night into Sunday morning

 Morning fog and rain gave way to afternoon sunshine as temperatures reached well into the 40s for afternoon highs. Some of that rainfall came down steadily last night, with a few locations near and Southeast of Rockford seeing more than 0.5" of rainfall just since Midnight. Rochelle and DeKalb observation sites recorded nearly an inch through the early morning! The Rockford airport officially saw 0.65" between last night (0.21") and this morning (0.44").

Our next weather system will arrive Saturday night in the form of a quick-hitting system that could bring a mix of rain and snow. The timing looks to be between 11PM-4AM, with a narrow window for the steadiest of precipitation. With temperatures only dropping to the low 30s, the rain and snow line could be very close by. Those North of Highway 20 will have the best chance for slushy snow accumulations up to an inch at the most, while those South may see a mix or even mostly rain.

We may see a few patches of drizzle or light rain showers linger into mid-morning Sunday, but by the afternoon we will be drying out as temperatures start to climb. Afternoon highs Sunday could even reach near 50° or higher if we see more sunshine!

The next main weather system looks to arrive in the Wednesday-Thursday timeframe, with a potential for wintry mix again. We will see a warm front lifting through the area Wednesday night, and the precipitation type could be dependent on where that warm front reaches by the time precipitation arrives. At this time, it appears we could see freezing rain followed by a cold rain, but stay tuned for updates!

Incoming steady rain will lead to dense fog, flooding concerns

Sunshine, gusty winds, and unseasonably warm temps have been the talk of the town this week. 

So much so that we were able to break a record high yesterday as the Rockford Airport peaked at 54°, breaking the previous record of 52° from 2012. In the "12 seasons" of the Midwest, this is known as "Fool's Spring" where we first see a spread of unseasonably warm temperatures during the winter season. Friday features a shake up in this weather pattern, which includes a couple of alerts. The first being a DENSE FOG ADVISORY which will be in place area-wide until 9AM. Visibility prior to the morning commute is sitting at or below a half mile, which is what we'll see into mid-morning. 

The National Weather Service has also placed Ogle, Lee, Whiteside, and Dekalb Counties under a FLOOD WATCH. With steady rain chances in the forecast today, flooding may occur in poorly drained and urban areas. If you live along the Rock River, keep an eye out for flooding due to ice jams. This will be in place through the afternoon. 

 

Rain remains likely into midday, with more tranquil conditions settling in for afternoon. On the northern side of this storm system, winds will be oriented out of the northeast, limiting afternoon highs to the low 40s. Believe it or not, today's high of the 41° will come in above late-January standards. We hold on to partly cloudy skies overnight, with this cool northeast wind leaving lows in the low 20s. 

 

Clouds and this cool northeasterly wind hang tight for the entirety of our Saturday. However, temperatures stay mild with highs in the upper 30s. A disturbance coming in Saturday night into Sunday may bring a small chance for a rain/snow mix. Otherwise, the bigger headline with this system will be the massive warm up that occurs for Sunday. Following it's warm front, winds turn to the southwest, allowing us to see the possibility one more 50° day before we cool back down into the low 30s next week.

Periods of steady rain overnight into Friday morning

 After record-breaking warmth Thursday afternoon, cloud cover has been thickening up. This comes along with some pockets of light rain, drizzle, and fog now entering Southern portions of the Stateline.

This area of drizzle/fog will continue to drift North through the evening, providing drops in visibility within the areas of drizzle and fog. Temperatures will only drop into the upper 30s through the evening as well. Within this drizzle/fog, we could see a few spots of light rain.

There may be a lull in precipitation rates near/just after the midnight hour, but drizzle and fog could continue to limit visibility, possibly down under a mile for some. Light winds and increased surface moisture will provide the necessary ingredients for areas of fog.

As the main low pressure system approaches tomorrow morning, steadier to heavy rainfall may be possible toward the daybreak hours. The heaviest rain is most likely between I-80 and I-90 corridors, with a sharp cutoff of the heaviest rain on the Northern edge. Some dry air in Wisconsin could limit the Northward extent of moisture.

The highest rainfall totals will likely end up along the Southern edge of the Stateline, with 0.5"-0.75" possible near or just South of I-88. Within that band, there may be some localized spots who could see 1.0" or more. Meanwhile, those in Southern Wisconsin will likely miss out on the highest rainfall totals, with many seeing under 0.25" or almost nothing.

Those who see the highest rainfall (especially near/above an inch) may have a risk for some flooding, given the deep frost depths owed to frozen ground from the Arctic chill a little more than a week ago. Most of the rain we see will be slow to soak into the soil and will have more runoff. We may also see some river flooding if the river ice builds up into ice jams.

The Weather Prediction Center highlights the risk for flooding well, showing a slight risk for flooding guidance near and South of Rockford. This translates to a 15% risk for flash flooding to occur within the yellow contour, especially between I-80 and I-88. Be aware of any potential flooding in low-lying areas and along riverways through Friday afternoon.

Record high temperature Thursday

 

A new record high temperature was recorded for Rockford Thursday afternoon as the mercury climbed to 55 degrees, breaking the previous record of 52 set back in 2012. 52 degrees also occurred on two other occasions - 1944 and 1926.

This is the second record high temperature recorded in the month of January. Back on the 17th the temperature warmed to 54 degrees. Not long after that, however, the temperature dropped significantly as an exceptionally cold air mass moved in pushing temperatures into the single digits and low teens for the start of the following week.

Cloud cover has moved in and thickened up quite a bit across the region late this afternoon causing temperatures to fall back this evening. These clouds are in response to an approaching storm system to the south that'll move from Missouri into central Illinois Friday morning. Drizzle and light rain showers are expected this evening, along with an increase in fog. Early Friday morning a round of heavier rain is expected to move in, especially for our southern counties. The rain will move out during the afternoon as temperatures are expected to fall throughout the evening.

Record warmth likely as this unseasonably warm week continues

It's absolutely crazy to fathom that 6 years ago today, the Stateline and a good chink of the Midwest was forecasting all-time record cold. 

Thankfully, that isn't on the table as the polar vortex is currently in a strong state, keeping the coldest air up in the Arctic Circle. In fact, temperatures this time around will be 65°-70° warmer, which will likely be enough to break today's record high.

Southwest winds take over for Thursday, which will result in a healthier temperature climb. Despite the fact that cloud cover will be on the increase this afternoon, confidence remains that temperatures will surge into the 50s. Currently, we have today's high at 54° which if that were to happen would break our daily record high of 52° established in 2012. This would also wind up being Rockford's first 50° day since December 28th (33 days ago).

Not too far behind the increase in cloud cover is our next chance for precipitation. For the most part, this event features scattered liquid rain, though colder air wrapping in may allow snowflakes to mix in during the first half of our Friday. 

With low pressure pivoting to our south, winds during the day will be out of the northeast. This will bring afternoon highs down a bit from today, leaving all Stateline locales in the low 40s.

Mild pattern continues with more frequent precipitation chances ahead

 After a near-record warm day on Thursday, we will remain mild throughout the weekend. Rain chances remain possible Friday, with a slim chance for some to see a few snowflakes mix in. We clear out into Saturday, with highs down in the 30s. Another incredibly mild day is in store Sunday with highs near 50!

Looking beyond the weekend, there is an interesting pattern that sets up aloft. This map shows temperatures about a mile up in the sky and generally shows where mild and cold air masses are. The Stateline will be directly between the warm and cold air masses, with the freezing mark directly overhead. Sometimes this can be the guide for weather systems to track along, but that proximity to the freezing mark overhead can also lead to differing precipitation types between systems with the rain/snow line likely developing near the freezing mark overhead.

This is an example of one of the weather systems that will track along that freezing line next week. We will have a more moisture-laden pattern with at least a slim chance for precipitation nearly every day from Thursday-on. It will not be raining all the time, but every day has at least a slim chance. Temperature-wise, we will be in the low/mid 30s for highs and 20s for lows, a bit above average.

That more active pattern looks to continue into the first week of February, with a slight favorability to see above average precipitation between the 4th-8th, per the Climate Prediction Center outlook. The same outlook for temperature favors neither above nor below average temperatures, indicating that buy and large we will be nearer our average temperatures of low 30s for highs and teens for lows.

 

Rain showers follow unseasonable warmth Thursday

 

For the third day in a row the high temperature warmed into the 40s, with Rockford's high reaching 47 degrees Wednesday afternoon. Temperatures will climb even further Thursday as a strong southerly wind takes hold, likely bringing the majority of the Stateline into the low 50s. South winds will gust close to 30 mph during the afternoon.

For the remainder of Wednesday evening skies will stay clear as temperatures drop back through the 30s, down into the upper 20s overnight. Winds will remain light as they shift to the south Thursday morning.

Thursday starts with a little bit of a chill, but temperatures will warm quickly during the afternoon. Highs will reach the low 50s, and possibly mid-50s, especially if cloud cover can hold off through most of the afternoon ahead of our next storm system. If clouds move in sooner temperatures would likely fall short of the 50-degree mark. The record high for the 30th of January is 52 degrees set back in 2012. The current forecast high is 53.

The arrival of the cloud cover during the afternoon and evening and will also come with the chance for rain. Rain showers will increase in coverage from south to north, moving into the Stateline Thursday evening. The exact amount of rain is still a little uncertain due to thunderstorms that'll be ongoing in the South. These storms could limit the overall amount of moisture into the region, limiting some of the higher rainfall totals. But it's likely that at least a quarter of an inch, if not close to half an inch, will fall through Friday morning. While this may not seem like a lot the frost depth is still rather deep in the ground and despite the warmer temperatures, little thaw has taken place. This would lead to more rain runoff into some of the local rivers, creeks, and streams rather than the rain soaking into the ground. River levels and the potential for ice jam flooding will be closely monitor from Friday through the weekend as a result.

Temperatures remain mild Thursday night before a slightly cooler air mass settles in Friday morning. This could lead to the potential for some snow to mix in with the rain, or even a short duration of all snow Friday morning. Little to no snow accumulation is expected at this time, but if temperatures trend slightly cooler for Friday morning, then we could see some impacts with the wintry weather. Highs on Friday will warm into the low 40s. 

Staying unseasonably mild ahead of our next storm system

Plenty of sunshine, along with the influence of gusty southwesterly wind, allowed spring-like temperatures to surge in for a second consecutive day.

Officially, Rockford peaked at 49°, which comes 20° above late-January standards. Temperatures stay mild for Wednesday, though won't be as warm as a cold front did come through overnight. 

Similar to Monday and Tuesday, a good mixture of clouds and sun is likely. Instead of winds being out of the southwest, we'll have a northwesterly breeze in place, which at times could gust up to 30 mph. This will bring temperatures down a few degrees, landing afternoon highs in the low 40s. Again, unseasonably mild. Skies remain quiet and partly cloudy overnight, with low temps falling into the upper 20s.

Ahead of our next system, winds swap back to the southwest for Thursday. This will allow afternoon highs to climb back towards the 50° mark. At the same time, clouds will increase as said storm system lifts northeastward out of the southern plains. Wet weather is soon to follow, with scattered rain showers sliding in Thursday evening. As colder air wraps in around the low's center, we could see snowflakes mix in during the first half of Friday.

Ice jam flooding possible with recent warmth and late week rain chance

 

The recent cold spell allowed quite a bit of ice to rapidly develop on some of the local rivers resulting in significant ice coverage over the last week. The warmer temperatures this week, and possible rain chances late in the week, may cause water levels on the rivers to rise - especially Friday and the weekend.

Temperatures Monday and Tuesday warmed into the mid and upper 40s, with 40s and likely low 50s expected Wednesday and Thursday. An incoming storm system from the southwest will move across the country into central Illinois late Thursday and Friday. To the south, severe weather will be likely in the southern Plains and Gulf states, while scattered rain showers (perhaps with some rumbles of thunder) occur in parts of the Midwest.

A period of light rain and drizzle will develop late in the day Thursday as low pressure tracks near or just north of St. Louis, MO before moving into central and northern Illinois Friday morning. While it's a little unclear at the moment just how much rain will occur, due to the impacts of moisture transport from storms down south, rainfall totals across at least a portion of northern Illinois could approach a quarter of an inch. 

While that may not sound like much, the current frost depth measured Tuesday morning was nearly a foot with little to no surface thaw being reported just yet. It's likely with the milder weather that there will be some thaw through the week, but it won't be deep enough to allow any rain that does occur to soak in which could lead to runoff into the local rivers. Not only would this cause a rise in some of the local river levels it could also cause further breakup and dislodging of river ice, leading flooding concerns due to ice jam flooding.

At this moment the risk is still low but something that will be monitored throughout the week. Those who live along the local rivers should continue to monitor the forecast and be prepared should there be rapid fluctuations in river levels.    

Second afternoon in a row where wind gusts could approach 50 mph

Winds were howling Monday, though thankfully these were very warm winds. This left afternoon highs in the mid-40s which is typically what we see average-wise in mid-March. The Stateline is in for a similar scenario today, with an organized warm wind resulting in a spring-like afternoon. 

Winnebago, Boone, McHenry, Ogle, and DeKalb Counties will be under a WIND ADVISORY from 2PM-6PM. Walworth County up in southeast Wisconsin will also be under a wind advisory, though the advisory starts an hour earlier. 

 

 

Those under the advisory will likely see winds peak between 45-50 mph. Winds this strong can make driving difficult, especially for those who operate a high profile vehicle. Fire danger will also be elevated so use extreme caution when disposing of smoking products. Also, postpone burning until another day. Similar to Monday, these organized winds will bring afternoon highs into the upper 40s, but chills will feel about 10° colder thanks to the strength of the wind. Cloud cover will start the day but then quickly clear as drier air moves back in. 

Forecast models then show another quick moving system sliding across the Midwest overnight, pulling another cold front through. This will come through dry, though winds will switch to the northwest. Afternoon highs Wednesday won't be as warm but still mild close to 40°.

Strong winds ease Monday evening, but pick back up Tuesday

 

Southwest winds were rather strong across the region Monday prompting the issuance of a Wind Advisory for a portion of the viewing area until 6pm. Wind gusts were close to 50 mph in a few locations, including Rockford. The wind advisory will expire at 6pm as the strong wind gusts are expected to ease some through the evening, however, remain close to 25-30 mph through the night.

The wind direction will briefly turn to the northwest through the night following the passage of a weak cold front. This front has brought an increase in cloud cover to the region with a few light radar returns showing up. However, given the extremely dry air mass in the low levels very little precipitation is expected to reach the ground. If we were to see anything it would be a light sprinkle or flurry late this evening. A warm front will then be quick to move in Tuesday shifting winds back to the southwest and bringing temperatures back into the mid and upper 40s.

Stronger winds aloft will once again move through the Midwest causing surface winds to gust around 40 mph Tuesday afternoon. Similar to Monday, this will bring afternoon temperatures into the mid 40s, but chills will feel about 10 degrees colder thanks to the strength of the wind. Cloud cover will start the day but then quickly clear as drier air moves back in. This will leave skies partly cloudy through most of the afternoon. Another quick moving system will slide across the Midwest Tuesday night pulling another cold front through. No precipitation is expected. Winds will remain from the northwest during the day Wednesday, but little cooling will take place. Highs on Wednesday will warm close to 40 degrees.

  

Wind Advisory with gusts as high as 50 mph possible Monday

Last week, a potent blast of polar air left the Stateline struggling to climb above the 0° mark. This week, it's the complete opposite as afternoon highs look to wind up roughly 35° to 40° warmer. How is this possible? Strong southwesterly winds. 

In other words, it will feel MUCH more comfortable outside, you just won't be able to enjoy it as much with such a strong wind in place. 

A WIND ADVISORY will be in place for Winnebago, Boone, McHenry, Ogle, Lee, and DeKalb Counties in northern Illinois from 9AM to 6PM. Walworth County up in southeast Wisconsin will be under the wind advisory from 8AM-6PM.

Those under the advisory will likely see winds peak between 45-50 mph this afternoon. Winds this strong can make driving difficult, especially for those who operate a high profile vehicle. Elsewhere, peak gusts could still reach 35-40 mph. These winds will force considerably warmer air into the Stateline, leaving high temperatures in the mid 40s. There will be plenty of sunshine to start, though cloud cover will start to build in during the afternoon. 

 

Overnight, a backdoor cold front will sink down into the Great Lakes, shifting our winds briefly to the northwest. Forecast models suggests there may be a few flurries with said cold front, though we may have to see if these flurries can fight off dry air. If not, then we won't see much if anything. Low temperatures will land in the mid 20s with clouds gradually clearing followed the cold front.

Period of strong winds possible Monday, wind advisory issued

 Monday will be a windy day across the Stateline, with some areas now seeing a wind advisory in place. Winnebago, Boone, McHenry, Ogle, Lee, and DeKalb Counties in Illinois will see that wind advisory run from 9AM to 6PM Monday, while Walworth County in Southeastern Wisconsin begins at 8AM and runs to 6PM.

The strongest of the wind gusts will be focused on the Northeastern portions of the viewing area, hence the limited coverage of the wind advisory. Those within the orange shaded area, from Monroe, WI down to Dixon, IL and areas East have the strongest potential to see peak gusts near 45 mph or greater out of the West-Southwest or Southwest. Elsewhere, peak gusts could still reach 35-40 mph. The time frame of the strongest winds looks to arrive by early afternoon.

Southwest or WSW direction of these strong winds will heavily dictate temperatures for the next couple of days. Monday and Tuesday could see afternoon highs reach well into the 40s, especially if we see more sunshine than cloud cover. Wednesday will also be breezy, with peak gusts near 20-30 mph, but this time from the Northwest. That will bring a brief cool-down with highs returning to the 30s.

One of the reasons for the strong winds is due to a feature called atmospheric mixing. This is when the air masses often mix down to the surface, drawing some portion of the wind speeds with it. In this case tomorrow, we will have strong winds of around 60 mph only a mile or so up in the atmosphere. The mixing down of those winds is what will bring 40-45 mph gusts to the surface. The more sunshine we see, the less cloud cover there is to block that mixing from occurring. Therefore, more sunshine can lead to warmer surface temperatures and in this case, stronger winds.

Though we will remain windy over the next couple of days, our precipitation chances are limited. Along a weak cold front Monday afternoon, we may see a few sprinkles or flurries try to work toward the surface, but these would be very light and scattered in nature if we see anything. There is a similar trend for a precipitation chance Wednesday morning, but widespread chances could return late in the week.