Soaking rainfall starts tonight, flips to snow Wednesday

 After a mild and even at times sunny afternoon, clouds have been filtering back in through this Monday evening. Our next wave of widespread precipitation will follow that, with scattered rain showers beginning shortly before or near midnight tonight. Temperatures will not drop far this evening with the increase in clouds and moisture. Overnight lows will likely range from the low to mid-40s.

We may get a brief lapse in precipitation toward early Tuesday morning, but much of the daytime Tuesday will feature widespread rain with steady to moderate bands within the showers. Rainfall rates could reach near or above 0.25" per hour, which will likely cause some ponding on roadways within the heaviest rain. This will continue into the evening before another break in those precipitation rates as the surface low pressure system passes overhead Tuesday night into early Wednesday morning.

 

Once the low pressure clears us to the East, much cooler air will begin to wrap in behind it. Temperatures will quickly drop from the 40s Wednesday morning to the 30s by afternoon. This will flip our precipitation over to snow near 12PM, with some bands of steady snow showers possible through the afternoon until drier air arrives late. This flip to snow will also be paired with a stout NW wind, gusting near 40-45 mph. That will cause significant drops in visibility even if the snow remains somewhat light. Snowfall accumulations do not appear to be that significant locally due to the mild and wet ground leading up to it, but some minor accumulation on grassy and elevated surfaces may be possible.

In total, widespread rainfall will reach near or above an inch for most in the Stateline. This could cause some flooding in low-lying areas, especially if most of that rain comes down between Tuesday morning and evening. Generally speaking, I expect most of the Stateline to receive between 0.75-1.5" of rain, with some localized higher amounts, especially within any embedded thunderstorms. Things will dry out for the daytime on Thursday before our next round of rain or wintry mix Thursday night into Friday.

Soaking rainfall, wet snow on the table this week

You'll need to swap those handy dandy sunglasses for an umbrella this week as our weather pattern becomes a bit more amplified. 

The Stateline begins the work week under a blanket of clouds, with temperatures sitting in the upper 20s and low 30s. With this cloud cover may come a very low chance for sleet or a wintry mix, mainly during the mid to late morning hours.

Conditions will then quickly dry back out for this afternoon, possibly bringing the chance for some sunshine. That, along with an organized breeze out of the south and southwest will help afternoon highs peak in the upper 40s, close to 50°. 

Our first real shot at seeing some rainfall comes in late tonight into the first few hours of Tuesday in the form of scattered showers. Thanks to tonight's rain and southerly breeze, overnight lows will stay quite warm with in the upper 30s.

Now, while the umbrella won't be necessary today, you'll want that in hand for Tuesday. A strong and impressive low pressure system will sweep across the central plains, allowing steady and more widespread rain to settle in for the afternoon. 

Though forecast models didn't show much instability or atmospheric energy in place, a rumble of thunder or two cannot be ruled out. Rainfall totals of an inch or more are expected, setting up the potential for some localized flooding. 

As the warmer air pushes east, cold air on the low's backside will help transition our precipitation from rain to snow by Wednesday afternoon. Not only that, winds become quite strong, gusting up to 35 to 40 mph out of the northwest. This will help bring our temperatures down throughout the day, landing us in the low to mid 30s by the afternoon.

Widespread precipitation Monday night through Wednesday

 Our next round of widespread precipitation will arrive Monday night through Wednesday. This strong low-pressure system will bring the potential for soaking rain and even some isolated thunder, especially Tuesday morning through evening. Colder air will then filter in through Wednesday, flipping things over to snow by afternoon. This system will be accompanied by strong winds, particularly Wednesday afternoon and evening, with NW gusts nearing 30-40 mph. See below for a rough timeline from Monday night through Wednesday, with expected precipitation on top and potential wind gusts and direction below the timeline.

For those more visually inclined to see future radar projections, here is the Futurecast model showing the start of rain showers after 12AM Tuesday, with more widespread and soaking rain arriving for much of the daytime hours on Tuesday. We could also see a few rumbles of thunder Tuesday morning and afternoon, depending on some possible elevated instability. The surface low pressure will bring its "dry slot" our direction Tuesday night and Wednesday morning, easing winds and precipitation temporarily. Then, colder air will bring a flip to snow early in the day of Wednesday. With the wet ground, snowfall rates would have to be pretty heavy for any accumulation more than a dusting, so only minor snow accumulations are expected at this time. But that will come with strong winds, so visibility may be a big issue Wednesday afternoon as the snow is falling.

The rainfall and melted snow may exceed 1" of total precipitation for many in the Stateline, especially those Northwest and West of Rockford. This could cause some flooding in low-lying areas given the limited topsoil to thaw out thus far. Be prepared for some minor flooding if rainfall exceeds 1" between Tuesday and Wednesday.

Higher precipitation chances to start the week

 As we begin to round out the weekend and move into the next work week we'll continue to see much of the same as yesterday where clear skies and cooler conditions will hang around the state line. As high pressure continues to move overhead a lack of moisture along with stronger pressure will keep us calm and dry for the rest of our Sunday. As we move into tomorrow and the days to follow though, our precipitation chances quickly begin to rise.

Starting tomorrow morning, a brief system will move through the morning hours, which won't be as heavy as the events to follow. Still with a little bit of lift and moisture in the atmosphere some rain and even winter precipitation will be possible during the morning commute. However, as we move into the night, our first spring like weather system will move in bringing multiple rounds of rain and possible snow lasting until Wednesday.

Starting with tomorrow's chances, a brief "vorticity max" or an area of extra lift will move into the area during the morning coupled with some moisture. Although this won't be as widespread, slick conditions on roadways may be possible tomorrow morning as morning temperatures may still be below freezing when these showers arrive.

Into Monday night, the leading edge of a large trough will move in with plenty of moisture allowing for widespread rain showers Monday night and into Tuesday morning. These will only be the first of a few rounds yet to come but as we move into Tuesday morning, we could begin to see a little break in precipitation until we reach the afternoon.

Moving into the afternoon and evening of Tuesday precipitation chances will continue to increase as even more moisture will be present at this time. Widespread rainfall is looking likely for the majority of Wednesday as the combination of good moisture and lift will be present. Temperatures will be near 50 degrees however with a low-pressure system very close by, we'll see stronger winds combined with heavy rainfall. As the low-pressure system moves east of us colder air will begin to wrap around the backside of the low cooling temperatures below freezing. Although moisture won't be as strong within this cold air, there will still be enough present for some snowfall Wednesday, the good news is though accumulation looks to stay below an inch.

Even though snowfall may be below an inch, before that with multiple rounds of rain on Tuesday widespread rainfall totals over a half an inch look likely with this system. As we get closer these totals will be known better however as it looks right now this looks to be our first "soaking" system of the year with some models showing over an inch of rain possible in some locations.

A brief break will arrive on Thursday, however as we look towards the end of the week another low-pressure system will track close by once again bringing more precipitation chances. As it stands right now, not much agreement can be made on precipitation intensity or type however the chances do look possible going into Friday for more rainfall and even accumulating snow. Spring is here in the upper levels of the atmosphere as the jet stream continues to become more active! With these systems our precipitation chances all rely on if we land on the cooler or warmer sides of these systems!

 

Widespread precipitation with dynamic weather system next week

 After a quiet weekend with the influence of high pressure, an active pattern will take hold next week. A strong low-pressure system will slide through the Central U.S. Tuesday into Wednesday, bringing with it the potential for heavy rain, thunderstorms, and even snow. The low pressure will pass directly over Northern Illinois, so we may be in for a little bit of everything.

Initially, soaking rain will be possible starting Monday night and Tuesday morning. Periods of steady to moderate rain will then be possible through Tuesday night. As colder air arrives Wednesday afternoon, there may be a window for precipitation to flip over to snow. The heaviest snowfall accumulation will remain Northwest of the low pressure's track and out of the Stateline. That said, we will likely still see some snow during the second half of Wednesday, with lighter accumulations possible. This system will also bring strong winds, initially from the Southeast Tuesday ahead of the low pressure's center, then Northwest Wednesday afternoon and evening.

In total, there may be a few spots that see precipitation amounts exceed 1" between Tuesday and Wednesday. This would be from rainfall and any melted snow. With the ground still somewhat frozen, there may be a small concern for isolated flooding in low-lying areas where the heaviest rain falls. Things will dry back out a bit for Thursday before another system arrives late-week.

Cooler weekend with plenty of sunshine

 As we come to a close on last week where multiple days were above average in terms of temperatures, we begin to look at the weekend where we cool down a little bit. Yesterday alone got up to 58° in Rockford which came just short of the record high of 62°! As we go into the weekend though, cooler northwest flow along with high pressure at the surface will keep us cooler but calm as well. 

With today being the first day of March, this is a special day for meteorologists as it marks the first day of Meteorological Spring! With that being said, we're only 19 days away from the "official" start of spring where our sun angle begins to change. However, today won't feel like spring as we'll be in the 30's but with high pressure setting in through the afternoon, the good news is that will bring in calmer conditions into the evening!

With high pressure moving in, winds will begin to lighten up throughout the day, but the morning still will remain breezy. As dry air moves in through the morning skies will being to clear as well offering mostly sunny skies for the rest of the day! This will last into tonight as well where clearer skies will allow our temperatures to drop into the low teens overnight.

Clear skies will continue into tomorrow along with calmer conditions. The high-pressure system will be directly overhead tomorrow providing even calmer conditions while a bit more sunshine may push us near 40° tomorrow. As we move into the night though a shift in the jet stream will allow higher moisture and upper-level winds to move into the area creating cloud cover as well as increasing precipitation chances as we move into Monday morning. 

 

Strong winds persist into Friday evening, cool down to follow

 6PM UPDATE: While it remains windy across the Stateline, gusts have been gradually decreasing. Many gusts are near 40 mph as of 6PM. The wind advisory was allowed to expire for most of NW IL and Southern Wisconsin. Highlighted counties remain under the advisory through 8 or 9PM.

It was a downright windy day across the Stateline Friday, with peak wind gusts of 45-55 mph across the entire area. The strongest of the winds were over the late morning into the early evening, with gusts in excess of 40 mph still as of 5:30PM.

A wind advisory will remain in effect until 6PM for the following counties: Jo Daviess, Stephenson, Carroll, and Whiteside in Illinois, along with all of Southern Wisconsin. The rest of Northern Illinois will see the advisory last until 9PM. This is for the continued potential for gusts to reach 45-55 mph. Further West in Iowa, a high wind warning is in effect -- for 60 mph damaging wind potential.

A pair of cold fronts are to thank for much of the wind, along with the strong low-pressure system to the Northeast. The cold front will also bring a big cool down overnight, with temperatures reaching the low 20s and upper teens for some by early Saturday morning. Winds will not be quite as strong during this window, but wind chills could briefly touch the single digits during this time. We may also see a stray rain shower or snow flurry through 4AM, but many if not all will remain dry.