Chilly night ahead, active pattern begins Monday night

 Temperatures are dropping quickly this evening, down into the mid-50s already for most as of 8PM. We will likely see most reach all the way down into the 40s by early morning, a very cool night ahead! Cloud cover will build back in toward the middle of the day, with a few afternoon showers possible. Afternoon temperatures will be held to the low and mid-70s despite a breezy Southeast wind.

Steadier or heavy rain will be more likely into Monday night and early Tuesday as the cold front on our trailing system arrives from the Northwest. This front will stall nearby or overhead, allowing for some very heavy rainfall to develop nearby. Heavy rain may persist into early Tuesday morning, with scattered showers and thunderstorms continuing Tuesday afternoon.

More rounds of heavy rainfall may be possible Wednesday evening into early Thursday, which may pose a larger risk for flash flooding especially over areas that see heavy rain from Monday night's rain.

Active pattern returns, heavy rainfall possible starting Monday night

A more active pattern will develop over the next few days, including a threat for some heavy rainfall mid-week. It will originate from a stationary boundary nearby. This boundary will act as a ramp to life moisture up and over, before falling as rainfall on the other side.

Repeat this process over and over again, and rainfall will add up quickly. Several weather models are predicting an axis of 2" of rain or more may be possible at least across parts of Iowa. Locally, it will depend on where the front ends up each day, and the frequency of showers and storms over any particular region. If storms develop over the same spots, flash flooding may be a concern, particularly Wednesday and Thursday.

Warm start to the weekend, shower chances return Sunday

 The weekend will start on a warm note, with afternoon highs reaching into the 80s Saturday afternoon. A cold front will pass through as a dry one, meaning most if not all of the Stateline will stay dry. But there will be a noticeable jump in humidity compared to Friday.

Sunday will bring eventual chances for showers our direction starting in the afternoon and evening. The window of moisture is relatively narrow, which likely keeps the coverage of rain to a minimum. Afternoon cloud cover will keep temperatures limited to the mid-70s at most Sunday afternoon. Another push of dry air will result in some cooler nighttime lows heading into Monday morning.

Active pattern returns next week with stationary front nearby

 Next week will begin to feel a little more like fall when it comes to precipitation chances and temperatures, starting with a broad cold front that will stall out nearby toward mid-week. On the Southern side of this front, temperatures may remain near 80 degrees with scattered showers and a few storms. North of the boundary, temperatures will remain in the 70s or cooler, with drier air and less chances for rain.

This front looks to slide back and forth across the region over the next week, bringing more abundant moisture nearby at times. This will bring frequent chances for rain and occasionally some storms. Monday evening through early Tuesday is the time span that looks most confident on shower potential, but periodic showers will become more common anytime next week as the front remains nearby. Air temperatures each day will depend heavily on the position of the front and potential rainfall coverage. Either way, it does look like 70 degree highs will become more common over the next couple of weeks compared to the 80s and 90s as of late.

Comfortable Friday on tap, Few showers possible for the weekend

 

Thursday's cloud cover cleared up just in time for many of us to enjoy a beautiful, and comfortable, September afternoon. Temperatures warmed through the mid and upper 70s, with a few spots reaching the low 80s. Some fair-weather cumulus clouds have developed over the last few hours but those won't last too long into the evening. With high pressure settling in tonight skies will clear, and temperatures will drop back into the low to mid 50s. Be aware, though, that there could be some fog - locally dense fog - early Friday given the fact that we will still be hanging on to some low-level moisture. That could slow you down just a bit for the morning commute.

Friday is shaping up to be another comfortable afternoon with plenty of sunshine and temperatures warming back near 80 degrees. Winds will remain light in the morning but increase slightly from the southeast during the day. Heading into Friday evening skies will remain clear with temperatures slowly falling through the 70s. There should be no weather delays with the Friday night football games but make sure you grab a jacket because it could get a little chilly once the sun sets.

Heading into the weekend there will be another cold front that'll move in from the west and northwest. This front has slowed down just a bit, likely not coming through until Saturday evening. A few clouds and a couple of light showers may try to sneak into the region Saturday morning, but that moisture will be battling the dry in place from Friday night. We'll see some clouds during the morning Saturday but perhaps a little more sunshine in the afternoon. As winds begin to pick up from the southwest temperatures should warm into the low to mid 80s. While a few showers are in the forecast Saturday, there should be quite a bit of dry time throughout the day.

Sunday may be our best chance for some rain as several upper-level disturbances move through the Midwest and Great Lakes. Clouds will increase during the morning and afternoon with a steady increase in scattered showers by evening. Temperatures on Sunday could be a bit cooler with high pressure to our north and a brisk northeast wind. Temperatures may only rise into the mid-70s during the afternoon.

8th warmest start to September as temperatures stay above average

September Heat:

September has certainty started on a hot note across the Stateline. Through the first eight days, Rockford's average temperatures sits at 77.9 degrees, placing it eighth-warmest start to September on record. A stretch that includes afternoon highs in the low 90s during the first 4 days of the month, combined with well-above average overnight lows. 

Staying Above Average:

Despite a cold front moving through the Stateline this morning, temperatures are still expected to climb into the low 80s this afternoon, with some locations reaching just above the 80-degree mark. Expect skies to remain mostly cloudy for much of the day, though some breaks are possible later on. A lingering shower cannot be ruled out during the afternoon, but the trend will be towards improving conditions as the best rain chance pushes south with the front. 

Pleasant Thursday:

Dry weather settles back in on Thursday as an area of high pressure builds in behind today's front. The influx of cooler, less humid air will make for a great September day, featuring lots of sun, comfortable humidity, and highs in the upper 70s. 

  

Warming Back Up:  

Unfortunately, the cooling trend doesn't continue beyond Thursday. Winds will shift to the south Friday and then to the southwest for Saturday and Sunday, allowing warmer air will once again surge into the Stateline. This return flow will allow afternoon highs to climb back into the low 80s, extending September's stretch of above-average warmth.  

Rain and embedded thunderstorms move in late Tuesday night

 

Non-severe thunderstorms will move across northern Illinois and southern Wisconsin Tuesday night, lasting through Wednesday morning. Pockets of heavy and steady rainfall will be possible through the night, but the highest rainfall totals are expected to occur over central and eastern Iowa. There, rainfall totals of nearly two inches could come down.

Closer to home rainfall totals between a quarter and three quarters of an inch will be more common, but a few spots could come close to an inch if repeated rounds of heavy rainfall come through. This is most likely west and southwest of Rockford. Most of the rain will be wrapping up mid to late morning Wednesday but a few showers could last through Noon. Mostly cloudy skies will then take us into the rest of the afternoon.