Summer vibes return—storm chances climb

Extremely Dry May:

Talk about a flip of the switch. Just weeks after seeing the 7th wettest April on record, the Stateline has done a complete 180 -  May is now trending as the 4th driest on record so far. From soaking rains and multiple episodes of severe weather to extremely dry conditions, it's been a dramatic shift in our pattern, and one that's been felt by many.  

Dry & Warm Friday:

We did see a weak system come through overnight, bringing us a few light showers. A lingering shower and some early clouds will hang around for the start of the day, but improvements are on the way. Sun gradually breaks through as we get into the afternoon hours. That, along with a increasing wind out of the south will result in a warmer and above-average end to the work week with upper 70s.  

Overnight Storms:

Our attention will then turn to the west where storm are expected to develop across Iowa. Those storms could organize and maintain some strong to severe characteristics as they track east over the Mississippi River. While they may gradually weaken, strong winds, heavy downpours, and hail will be the primary concerns with any severe storm.  

Weekend Outlook:

The rest of Saturday aims to remain dry. After early-day clouds give way, we'll stay dry through the afternoon with highs climbing into the mid 80s - a very summer-like afternoon. 

That said, the quiet stretch won't last long as another round of storm chances arrive late Saturday into Sunday. This may end up putting a lid or cap on the atmosphere for the rest of the afternoon and evening. Even so, we'll need to keep an eye on things as we do have a warm front lifting through late Sunday morning into Sunday afternoon. The highest potential as of this morning comes in on Monday as a strong low and a cold front enter the equation.  

Increasing thunderstorm chances starting this weekend

 Humidity is not something we have needed to talk about for a while, but this weekend will bring a very muggy feel compared to average conditions for mid-May. Dew point temperatures will surge all the way into the 60s beginning Saturday afternoon, until a cold front swings through Tuesday.

Moisture is just one ingredient for thunderstorms, though. Instability is a measure storm energy, describing how quickly air will rise and form an updraft. Saturday through Tuesday will bring substantial amounts of instability nearby and especially to the West, but the main question is if there is enough forcing to develop storms.

Each day Friday through Tuesday features at least an isolated severe weather potential nearby. Friday night and Saturday both have Level 1/5 Marginal risk for parts of the area, indicating an isolated severe storm may be possible, primarily in the evenings.

The Storm Prediction Center has 15% risks nearby or overhead (Monday) each of Sunday, Monday, and Tuesday. Monday has the best environmental conditions for severe storms, but each day may feature some strong storms. The exact timing of each wave will be hard to pinpoint until closer, as previous waves will determine outflow boundaries and other small-scale features that will impact storm threats.

Dry start to the month of May

 

Following a very wet April the first two weeks of May have been exceptionally dry. With only 0.05 inches of precipitation being recorded at the Rockford Airport this May, month to date, is the second driest start to May since records began in 1905! It follows 1958 and ties with 1928 - two years that were a long time ago.

The surplus of rainfall during the month of April helped bring northern Illinois and southern Wisconsin out of drought conditions but it has really dried out over the last two weeks, even though it has also been a cooler start to the month. Rain chances do look to ramp up heading into the weekend thanks to a more active pattern that'll start to take shape Friday night.

Skies will remain mostly clear through Thursday evening as high pressure hangs on across the eastern Great Lakes. You'll start to see an increase in some higher-level clouds, already moving in across northwest Illinois, through sunset. These will thicken up as a warm front moves a little closer. There are a few showers and thunderstorms ongoing across Iowa and Minnesota but those will continue to fizzle as they encounter the drier air to the east. Late Thursday night an upper-level disturbance will move in giving us a chance for a few passing showers into Friday morning. Any steady rain and thunderstorms will likely miss us to the south over central Illinois.

The warm front will pass to our north Friday afternoon as southerly winds increase, gusting around 30 mph. This will help push afternoon temperatures into the mid and upper 70s. Most of the afternoon will remain dry but the chance for showers and thunderstorms is set to return Friday night with the arrival of a cold front. While not much cold air is behind this front, it will be the focus for showers and thunderstorms heading into the weekend. 

Strong to severe storms are likely to our west Friday afternoon and evening, and that's where we find a 'slight risk' for severe storms - centered over southern Iowa, northwest Missouri and southeast Nebraska. Further east, a 'marginal risk' for isolated strong to severe storms can be found over most of northern Illinois and southern Wisconsin. This would be for any storms we get overnight Friday. The main risks with those storms would be primarily hail. 

The front will stall over the region Saturday afternoon and will be the focus for additional showers and thunderstorms during the afternoon and evening.     

Temps rising, storm chances back for the weekend

Windy Stretch:

It's been a blustery stretch across the Stateline the past few days, with persistent winds making it feel cooler than the thermometer might suggest. Yesterday was a good example of that, as the steady breeze help hold afternoon highs in the low 60s.

  

Warm Up Commences:

Winds ease up quite a bit today, and while we'll still have a breeze, it won't be nearly as impactful as what we've dealt with recently. Even better, that wind will shift out of the southeast, tapping into a warmer air mass and helping temperatures rebound. With a high pressure system nearby, skies will end up mostly sunny for most of the day, allowing afternoon highs to climb back to seasonable levels.   

Rain Chances Return:

Moving into tonight, our next chance for rain arrives as a weak system slides in ahead of broader troughing off to our west. Clouds will gradually increase through the evening, with scattered showers arriving close to or shortly after midnight. These showers look fairly light in nature, though a heavy downpour or two cannot be ruled out. Chances should linger into the first half of Friday before clouds give way to some sunshine by the afternoon. 

Weekend Severe Potential:

By the weekend, our focus will turn to the heightened potential for strong to severe storms, especially on Sunday and Monday. A warm front is expected to stall nearby, creating a favorable setup for stronger storms to develop. As of this morning, the Storm Prediction Center places the entire under a level 1 Marginal Risk for Saturday, but indications point to a higher threat level as we head into the latter half of the weekend and early next week.     

Gusty winds ease Wednesday night

 

The winds were strong once again Wednesday afternoon with peak gusts reaching 30-35 mph in some spots. The northwest breeze helped keep afternoon temperatures in the low to mid-60s. Outside of the wind, it's been a nice afternoon.

High pressure settling closer to the Stateline Wednesday night will allow our gusty winds to ease and skies to clear. Temperatures will slowly drop through the evening, settling on either side of 40 degrees Thursday morning. A few spots of frost may be possible but mainly for our typical cool, low-lying areas. I do not expect anything widespread Thursday morning.

Winds will remain light for most of the day Thursday under mostly sunny skies. Temperatures will warm into the upper 60s and low 70s. Clouds will be on the increase Thursday evening with the arrival of a warm front. This will bring with it a chance for a few passing showers and isolated thunderstorms overnight Friday, into Saturday morning.

Look for our gusty winds to continue through sunset, quickly dropping off this evening.

Brief cooldown, then quickly warming into the weekend

Breezy Conditions Remain:

We're coming off a blustery Tuesday, and that wind isn't letting up as we head into Wednesday. While peak gusts ease a bit, a steady northwest breeze will stick around, continuing to usher in cooler air across the Stateline. That shift in wind will keep afternoon highs in the low 60s - still on the cooler side for this time of year. Normally, we're near the 70° mark as we jump into the second half of May.   

Temperatures Surge:

In better news, this cooldown won't stick around for long. By Thursday, winds on the backside of a surface high pressure system will swing to the southwest, allowing a quick surge in temperatures to occur. That warmer flow will help bring highs back towards the 70-degree mark, with even milder air settling in by Friday afternoon - pushing us past 70 degrees and right back to a more seasonable feel.   

Showers Thursday Night:

The highest chance for rain in the days leading up to the weekend will arrive Thursday night into Friday morning. Moisture will be on the increase as a weak disturbance slides in, though coverage remains quite scattered so not everyone will see rain. Expect a few passing showers before conditions gradually settle down as we head into Friday afternoon.  

 
 
 

After brief cool-down, summer-like pattern arrives this weekend

 Tuesday was characterized by scattered showers and abundant cloud cover limiting afternoon highs to the low 70s for most. Along a cold front this evening, we may see another isolated shower or storm develop through 8PM. Most of the area will remain dry, however. Winds will pick up right behind the front, gusting near 30 mph at times out of the Northwest. As skies clear late in the evening, temperatures will drop down toward the upper 40s.

Temperatures will only rebound into the mid-60s on Wednesday with a continued North-Northwest breeze and a building cloud deck. There is a very limited chance for a few sprinkles, but most will again remain dry. Lighter winds Wednesday night will allow for some patches of frost to develop by Thursday morning, but afternoon sunshine will warm temperatures back into the upper 60s.

A warmer, summer-like, and active pattern will begin to set up later this week into next. This will be denoted by a rise in Gulf moisture flowing North into the Central United States. Local afternoon high temperatures will push into the upper 70s to near 80 several days. The added moisture will also produce daily thunderstorm chances, beginning Thursday night into Friday. Higher coverage and frequency of rain will be most prevalent Sunday through Monday night.