Shower and thunderstorm chances on the rise the next few days

 

It'll be yet another comfortable afternoon today as temperatures are expected to be slightly warmer than yesterday with plenty of sunshine to start. Through the day though expect clouds to gradually build as our next system approaches from the northwest. With this system will come a cold front that will bring precipitation chances tonight lasting through Thursday potentially. 

The first of which will arrive late this evening into tomorrow morning as our next cold front approaches. Through the overnight hours tonight, scattered showers and even an isolated thunderstorm will be possible as this front moves in, however expect conditions to clear by daybreak.

Depending then on how our atmosphere recovers into the afternoon another round of both showers and thunderstorms will be possible. We'll have quite the active storm system around which will easily force showers and thunderstorms as long as our atmosphere is able to build enough energy through Wednesday morning. If this were to occur, another round of showers and thunderstorms would be possible Wednesday afternoon.

Even though chances for showers and thunderstorms will be there almost daily the next few days, severe thunderstorm chances will remain quite low. Tonight's round of storms are expected to stay below severe criteria while tomorrow an isolated severe storm can't be ruled out for areas south of I-88.

Over the next three days this incoming system will offer multiple chances for both showers and thunderstorms. This will offer another chance for higher amounts of rainfall for the region after just another heavy rainfall event last weekend. Thankfully, flash flood potential should remain low over this time, however still pay close attention to when heavier downpours occur. 

High pressure holds strong before a midweek pattern change

Comfortably Warm Monday:

We kicked off the new work week on a pleasantly warm note weather-wise. Plenty of sunshine filled the sky Monday, while temperatures stayed a few degrees below average for early August. 

It was a touch muggy at times, with dew points in the low 60s, but overall, conditions remained comfortable for those that had any late-summer plans.  

Another Quiet Night:

All remains quiet this evening and overnight as high pressure stays firmly in control across the region. A few passing clouds are expected, but overall, skies will remain clear, bringing us the potential for some shallow fog by the morning commute. However, the nature of tonight's fog should not end to the extent of what we saw this morning. Overnight temperatures will fall back into the low 60s, making for another mild but comfortable night. 

Next Cold Front:

Most of Tuesday will remain dry, though we will begin to notice some changes as our next cold front approaches from the northwest. Clouds will gradually increase through the afternoon, signaling the arrival of said frontal boundary. The front is expected to move on through late Tuesday night into the early stages of Wednesday, bringing with it the chance for thunderstorms and heavy downpours.  

Severe Potential is Low:

While a few rumbles of thunder is possible, the latest outlook provided by the Storm Prediction Center does not have us under any severe risk. 

 

  

Same for Wednesday, though our "in-house" model does have a potent cluster coming in during the late-afternoon - early-evening time frame. If more of the severe ingredients work their way in, I could see the Storm Prediction Center expanding that level 1 of 5 Marginal Risk into central Illinois. But for now, keep a close-eye on the forecast as changes are likely as go through Tuesday and into Wednesday.    
 

Locally dense fog to start morning; pleasant conditions into afternoon

 

With calm conditions expected this morning along with dewpoint temperatures close to our actual temperature, locally dense fog will be possible this morning. Due to this, the National Weather Services in Chicago and Quad Cities have issued Special Weather Statements for all of Northern Illinois highlighting the possibility of visibility dropping below a quarter mile. However, conditions should begin to rapidly improve close to 9 a.m.

Through the rest of the afternoon conditions will remain comfortable with temperatures climbing into the low 80’s and humidity conditioning to remain rather comfortable. Sunshine will stick around through most of the day as well, however you may see a bit of haze due to wildfire smoke although we shouldn’t feel any effects down at the surface.

As we roll into the next three days not much is expected to change in terms of the forecast as temperatures will remain in the low 80’s to start the week. Sunshine will stick around the start the week however a mid-week system will help increase precipitation chances into the middle of the week.

Few pleasant days ahead of mid-week shower chances

 Once the clouds gave way to afternoon sunshine on Sunday, it was a pleasant evening. Similarly nice afternoons are expected for a couple days with afternoon highs climbing back to more seasonable trends in the low 80s. Outside of some patchy fog Monday morning, weather will likely be uneventful through Tuesday. Chances for rain increase mid-week along our next cold front.

The horizon may look a little hazy over the next few days. Smoke from the Pacific Northwest wildfires will work our direction in the upper levels. This will bring little to no impact to surface air quality in the near term, but additional smoke may linger through much of the week ahead.

A cold front later this week will bring our next rain chance beginning Tuesday night or Wednesday morning. A few storms will be possible Wednesday afternoon and evening as well, but very limited on the threat for any severe weather at this time. The front will clear to the South by Thursday afternoon, but additional waves may bring additional precipitation chances toward next weekend.

Drying out ahead of mid-week cold front

 It was nice to have a good soaking rainfall without severe storms between Friday and Saturday. Most in the Stateline ended up seeing between 1-2" of rainfall, with a few narrow bands of 2"+ across parts of NW Illinois and into Wisconsin.

We will soon dry out Sunday through at least the first half of Tuesday. Aside from some patchy fog the next couple of nights, weather will remain tranquil with afternoon highs reaching into the upper 70s and low 80s. We might see some wildfire smoke aloft over the next couple days, producing some hazy sunsets with limited concerns to air quality near the surface.

Our next cold front will slide in around Tuesday night through early Thursday. This slow-moving front will bring sporadic showers and a few storms along it, but there will be many dry hours during that time. All told, a few spots might be able to pick up another 0.5-1.0" of rain before the front settles down to the South.

Coverage of rain will peak between Wednesday and Thursday with around a 50-60% chance of rain during that time. Coverage will taper off Thursday night with high pressure settling in from the North before the pattern turns a little more uncertain by next weekend. At the very least, I do not see any expansive heat waves in the near term, with most days through next weekend in the low 80s for afternoon highs.

Pockets of steady to heavy rain Friday evening into Saturday

 [10:40PM] Pockets of steady to heavy rain will continue through the overnight window and into Saturday morning. Heaviest rainfall rates may exceed 1" per hour at times. Another 0.5-1.5" possible for some, with minor flooding concerns in low-lying areas.

[9:30PM] Steady rain persists for most late this evening with embedded pockets of heavy rain. Rain continues through the night and into Saturday morning, with the bulk of the remaining rainfall coming after midnight. Already, many to the West of I-39 have seen near or more than 1" of rain, with another 1-2" possible by the time rain ends Saturday evening. Be on the lookout for standing water in low-lying areas Saturday morning!

[6:15PM] Pockets of steady to heavy rain are moving back into the Stateline, especially across Jo Daviess County. There, some instantaneous rainfall rates are near 2-3" per hour. The slow-moving nature of these showers will result in quick accumulations as cells move to the Northeast at around 20-25 mph.

Coverage of rain will continue to increase through the evening, with likely widespread steady rain by the time we reach 8-9PM. Embedded within will be the heavy rainfall rates, possibly near 2-3" per hour at times. If these cells track over the same areas over and over again, rain will accumulate rather quickly. Be on the lookout for isolated flooding in low-lying areas this evening and tonight!

A good soaking rain with pockets of heavy rain will likely continue through the nighttime window and into the early morning hours of Saturday. Rain will finally begin to wind down after 4AM.

While the heaviest rain will be ending, light to steady rain will then continue through Saturday morning. Scattered showers will then remain possible through the duration of Saturday afternoon before rain comes to an end by the evening.

It will remain cool and breezy throughout, with limited temperature range Saturday. The morning will start in the mid-60s, and temperatures will only rise into the low 70s with a stout Northeasterly breeze. Wind gusts could reach 20-30 mph at times.

Slow-moving system brings much-needed rain back to northern Illinois

Rain Chances Return:

Following an exceptionally dry July and worsening drought conditions across northern Illinois and southern Wisconsin, much-needed rain chances are set to make a return to the Stateline. A slow-moving area of low pressure will drift across the Midwest before gradually tracking across Illinois Saturday, bringing periods of showers, possibly heavy, and thunderstorms back into the forecast.  

Heavy Rain Possible:

The first half of the day is expected to remain dry, though clouds will gradually increase ahead of the approaching storm system. 

Rain chances will begin to rise as we head toward midday and the early afternoon, with scattered showers and a few thunderstorms developing across the region. Those scattered rain showers will likely linger into the evening hours before a second, more widespread round arrives as we head into the overnight hours as the surface low slides in. If you are heading to any events this evening including City Market, Festa Italiana, or the Ogle County Fair, have an umbrella on hand. 

While severe weather is not anticipated near the Illinois/Wisconsin border, a few stronger storms may drift into our southwestern areas. That is where you will find a level 1 Marginal Risk for isolated strong to severe storms, with damaging winds being the main concern. And again, heavy downpours/flash flooding will also be a concern. Further to the southwest is where the highest severe potential (level 2 of 5 Slight Risk) resides where all severe hazards, including a tornado or two, will be possible. 

Rainfall Potential:

The tougher part of the forecast, rainfall totals. The reason why, forecast models continue to struggle with the exact placement of the center of the low, which determines where the heaviest bands of rain will set up. Right now, most will likely see 1-2" of rain, though it isn't out of the question for there to be very localized amounts above 2". The last time Rockford observed 2+" of rain, 49 days ago on June 11th, the same day of the central Illinois tornadoes.