Dry pattern holds as temps climb towards Memorial Day

Drought Conditions Return:

It's been a dramatic flip in the pattern across northern Illinois this month. We went from soaking rain in April - ranking as the 7th wettest on record - to a notably dry stretch here in May, which is now running as the 4th driest on record so far. The shift has been so significant that portions of northern Illinois are now classified as abnormally dry according to the latest edition of the Drought Monitor.   

Rain chances remain limited moving forward. We do have a couple of opportunities to squeeze out some rain - first with a few light showers late Friday into Friday night, and then again Saturday evening into the early stages of Sunday morning. 

Even with those windows, this won't be even close to a washout as a ridge of high pressure begins to build aloft, limiting widespread coverage and duration. City Market weather should cooperate, just with a bit more cloud cover overhead. Skies are expected to remain mostly cloudy throughout the event, but conditions will stay dry and comfortable. Temperatures will start off right near the 70-degree mark, then gradually easing back into the low 60s. 

Warm Memorial Day:

From there, expect temperatures to climb back above-average over the holiday weekend. Afternoon highs will top out in the low 70s Saturday, upper 70s on Sunday, and then low 80s Monday. With a ridge of high pressure in control aloft, we can expect these 80-degree temperatures to carry on well into the next week, at least into Wednesday.  

Drought conditions return as dry stretch persists into late May

 After one of the wettest Aprils on record, May has been the exact opposite. Warm and dry days have been far more common over the last few weeks. Through the first three weeks of May, the Rockford airport has only received 0.28" of measurable rainfall. Not only is that nearly 2.5" below average, but it is also the driest start to the month since 1992. If we do not accrue a full inch of rain by the end of the month, it will go down as a top 3 driest May on record.

It took a while to dig out of the drought conditions that we carried over from last fall. But since all the drought conditions had been removed back in early April, it only took a few weeks of a dry May to bring abnormally dry contour back into the region. Last week, only about 12% of the state was experiencing abnormally dry conditions. This week, that percentage is more than double, above 24%. The moderate and severe drought in Southern Illinois did not see any change from last week to this week.

But will we see any widespread rain anytime soon? The answer is probably not, as we are beginning to see more summer-like patterns in the atmosphere. The upper levels in particular are set to reach into a blocking pattern with dueling lows on either side of the country. That will force a warm and drier air mass across the Central third of the county, limiting overall rainfall potential.

While it is not totally dry, the rainfall we may see will not amount to much. More soaking rains may be possible South and well West of the area, but much of Illinois/Wisconsin will be removed from the highest rainfall potential over the next 5-7 days. Unfortunately, with more warmth on the way, that could lead to more developing drought conditions.

Cool now, summer later: Memorial Day warmth on the way

Monthly Recap:

May has delivered a mixed bag in the Stateline so far, with a noticeable tug-of-war between spring chill and early-summer warmth. Out of the first 20 days of the month, we've logged only 4 days stuck in the 50s and five days stick in the 60s, highlighting some of those cooler, cloudier stretches. But warmer air has made its presence known - 11 days have climbed above the 70-degree mark, giving the month a mild and at times summer-like feel despite those dips. 

Cooler Stretch Continues:

Looking ahead, it looks like those occasional dips will win out prior to Memorial Day as cloud cover works its way back into the Stateline. We'll especially notice that on Friday with thicker clouds limiting sunshine and keeping temperatures in check. Afternoon highs will hold in the low to mid 60s. Winds will also have a say as they will be out of the east-northeast today, then out of the east on Friday. 

Holiday Weekend Surge:

Fortunately, a much warmer pattern sets up for the holiday weekend. Temperatures will surge thanks to a strengthening ridge of high pressure building in aloft in the atmosphere. This displaces the jet stream far to the north, placing it across southern Canada. 

This type of setup will promote more sunshine as well as a steady warm-up, allowing afternoon highs to climb back into the 70s this weekend, and even the low 80s for Memorial Day and next week. Along with this ridge comes limited rain chances and extremely low severe weather potential.      

Clouds increase following comfortable Wednesday afternoon

 

After a chilly start Wednesday morning temperatures have warmed nicely for the afternoon, reaching the low to mid 60s. It has been a little cooler, however, for areas east of Belvidere and DeKalb where a lake breeze has kept temperatures in the 50s. The cooler air will begin to shift further inland over the next few hours, bringing temperatures down into the 50s for most between 7pm and 9pm.

Skies are mostly clear for now, but cloud cover will slowly increase from the west as a few little upper-level disturbances move in from the central Plains. While there is an increase in moisture with these disturbances, dry air from high pressure over the northern Great Lakes will limit most of the incoming moisture. This will leave us with a mostly cloudy sky later tonight and into the afternoon Thursday. As a result, temperatures will only warm into the low to mid 60s.  

Warm stretch ends as cooler air takes over before Memorial Day

Cooler Moving Forward:

The Stateline has been riding a stretch of beautiful, early summer-like warmth over the past few days, with afternoon highs peaking in the upper 70s and low 80s. But as is often the case this time of year, that warmth won't remain consistent. A cold front that swept through Tuesday has snatched that warmth away, setting the stage for a noticeably cooler stretch before Memorial Day weekend.   

Today starts on a much cooler note, with temperatures dipping in the low to mid 40s. That cooler air sticks around through the day, with afternoon highs only topping out in the low to mid 60s. Again, much cooler than your typically late-May standards. While it will feel noticeably different compared to the past two days, high pressure moving through will at least keep conditions pleasant with plenty of sun. We'll mix in a few clouds during the afternoon. 

Showers Return Friday:

We'll keep that cooler, quiet pattern into Thursday, with afternoon highs once again settling in the low 60s under a mix of clouds and sun. By Friday, highs may trend cooler as an easterly wind sets up, helping pull in more cloud cover and even the chance for a few passing showers. That added cloudiness and onshore flow will keep afternoon highs limited to the low 60s, round out a noticeably cooler end to the work week across northern Illinois.  

Cold front to bring another cool stretch to northern Illinois

Leftovers Once Again:

For the second morning in a row, northern Illinois is waking up to the leftovers of a severe weather event that originated in the central plains. A few showers, and even an isolated thunderstorm will be possible as a strong cold front pushes through. 

  

Clouds will hang tough through much of the day as a cold front gradually pushes across the region, keeping skies mostly overcast for the time being. As we head deeper into the afternoon, however, we should begin to see some breaks in those clouds. Temperature will respond accordingly, settling into the low 70s for highs. Behind the front, a shift to the northwest wind will usher in a cooler air mass, and that will become more noticeably this evening and overnight tonight as low temperatures aims for the mid 40s.   

Staying Cool:

A northeast wind take control on Wednesday, helping to keep temperatures running below average with struggling to climb out of the low 60s. That cooler flow will be paired with a partly cloudy sky as high pressure slides in from the northwest. Highs aims to remain in the low 60s for Thursday.  

Humidity retreats for a few days behind a cold front

 Tuesday will bring a cold front with a few stray showers pushing through during the early part of the day. Temperatures will fall over the course of the day, reaching the 40s by Wednesday morning. High pressure overhead will ease up the winds but also result in a cooler air mass overhead.

Humidity will fall away rather quickly behind the front. Dew point temperatures will fall below 50 degrees by Wednesday afternoon and not rise back above that mark until later Friday. Eventually, a small tug of moisture will return over the weekend with a smaller chance for some showers on occasion. Air temperatures will only rebound to the mid-60s with a pleasantly cool feel both Wednesday and Thursday.