Isolated showers/thunderstorms beginning to develop Tuesday evening

 UPDATE: Widely scattered thunderstorms continue to lift to the northeast late Tuesday evening producing mostly heavy rainfall. A few of the stronger cells may be capable of small hail and winds gusting 30-40 mph. These thunderstorms are moving to the northeast well ahead of a cold front still near the Mississippi River. While a low end threat remains for a strong thunderstorm or two, our severe risk continues to decrease.

The cloud cover from earlier in the day is beginning to clear giving us a little more sunshine Tuesday evening. The increase in sunrise has allowed the instability to also increase across northwest Illinois. This is ahead of a slow moving cold front that'll slide through northern Illinois and southern Wisconsin around Midnight.

Ahead of the cold front, isolated showers and thunderstorms are expected to develop - and have already started to develop in eastern Iowa and northwest Illinois. These storms have the risk to grow to severe strength, producing damaging winds and hail later Tuesday evening.

An uptick in storm coverage is expected over the next few hours, roughly between 7pm and 11pm, with the highest coverage likely south of Rockford across Whiteside, Ogle, Lee and DeKalb counties. With the cold front not passing through until Midnight, the threat for thunderstorms will continue through the evening.   

Severe Storms Possible Late, Cooler Time Ahead

Storm Chances Return:

Severe weather was the big weather headline on Memorial Day as a deepening low-pressure system brought multiple watches and warnings to a portion of the Upper Midwest. While the activity isn't expected to be as intense, the threat shifts eastward to our neck of the woods for our Tuesday. 

The early morning outlook from the Storm Prediction Center still places much of the area under a Slight Risk (level 2 of 5) for severe weather. Now, the one thing going for storm chances today is that there isn't expected to be any convection or storm activity during the morning hours. If we had showers and thunderstorms rolling on through this morning, that would mean the atmosphere would need to recharge for the late-day threat. However, the biggest question with today's threat is the amount of sunshine we see.

As the disturbance approaches, clouds are expected to increasing into mid-day, leaving us with mostly cloudy skies for the afternoon. Storm chances will be best between 3PM-8PM, with damaging winds and heavy rainfall being the main concerns. This is something to keep in mind if you are planning to grab some grub at Food Truck Tuesday.

While there isn't much "spin" in our atmosphere, a tornado or two cannot be ruled out, especially for areas along and south of interstate 88. A few storms may linger into tonight, with chances going down after midnight. We do keep a mostly cloudy sky into Wednesday. However, tonight's cold front will mark the beginning of a cooler and mainly dry weather pattern that sticks around for the remainder of the week. 

Trending Cooler:

As an area of high pressure takes over the central plains, winds Wednesday and Thursday remain out of the northwest. This will bring cooler, less humid times to the Stateline, with highs peaking in the lower 70s a partly cloudy sky. Aside from an isolated shower or two, rain chances moving forward remain low until the weekend. So, if you have to catch up on yard work after the holiday weekend, Wednesday and Thursday feature great weather for such activities. 

Strong winds and warmth continue Memorial Day evening

 
South winds were strong once again Monday afternoon, gusting 35-45 mph at times throughout the day. The combination of the strong winds, sunshine and a dry air mass allowed temperatures to warm quickly during the afternoon, reaching the upper 80s and low 90s area wide.

South winds remain strong through much of Monday evening, only falling to around 25-30 mph overnight. This will help keep temperatures in the low 70s through Tuesday morning.

The high temperature in Rockford reached 91 degrees and while not record breaking heat, it will go down as one of the top five hottest Memorial Days on record. The hottest Memorial Day, and record high for the 30th of May, sits at 96 degrees set back in 1936.

The cloud cover from earlier today has cleared, leaving us with mostly sunny skies that'll continue through rest of the evening. Clouds will slowly increase through the night as thunderstorms across the Upper Midwest move east, but skies locally are going to remain dry. Humidity will also go up Tuesday as moisture increases ahead of the incoming cold front. Temperatures on Tuesday will warm into the upper 80s ahead of the front, dropping to the low/mid 70s following the front for the remainder of the week. 

A nice but hot Memorial Day

Overall, Memorial Day Weekend was nice if you enjoy warmer weather. Temperatures were in the mid 70s Saturday with some sunshine and then they soared to near 90 Sunday. The hot pattern continues for Memorial Day with more sunshine returning. Get outside and enjoy the weather but remember to practice heat safety Monday and Tuesday. If you are not a fan of the near 90s/lower 90s, we will have a cold front that will drop our temperatures mid-week for the next several days after Tuesday. 

Temperatures are very mild Monday morning to kick off Memorial Day in the upper 60s/lower 70s as of 5am. Temperatures will rise very quickly through the remainder of the day. Enjoy any Memorial Day plans with the nice but hot weather.

The weekend not only brought warmer temperatures, but also breezy conditions. Winds are going to stay gusty Memorial Day and even into the next few days. Monday gusts could be as high as 35-40mph.

Tuesday will be the next better chance of a measurable rain across the Stateline. Rainfall amounts still do not look that impressive, right now it only looks like areas across the Stateline will receive about 0.05-0.50”. 

The Storm Prediction Center still has areas northwest of the Stateline highlighted for the best chances of severe weather Monday. As a cold front approaches us, we must watch this. The SPC has the Stateline under a slight risk (level 2 out of 5) for severe weather chances Tuesday. The time frame for storms across the Stateline is roughly about 2-7pm. However, the best chances for severe weather remains to our southwest where there is an enhanced risk (level 3 out of 5). Our threats include heavy rain, gusty winds, smaller hail and even a few tornadoes cannot be completely ruled out.   

Warm and Windy Memorial Day

Temperatures Sunday afternoon warmed into the mid and upper 80s, officially reaching 88 degrees in Rockford. While skies were partly to mostly cloudy at times, strong south winds helped bring temperatures nearly 10-12 degrees above average for most. 

Winds really started to increase during the afternoon, nearing 45-50 mph at times late in the day. While typically strong winds decrease as the sun sets and the night approaches, Sunday night will continue with rather strong winds thank to an increasing low level jet, where just a few thousand feet above the surface winds will be close to 60 mph. The strong wind momentum will transfer down to the surface helping to keep wind gusts between 25-30 mph through Monday morning.

As the sun shines bright Memorial Day temperatures will soar rather quickly into the upper 80s and low 90s during the afternoon. The forecast high for Rockford on Monday is 91 degrees. While it'll be hot, it won't be overly humid. Dew point temperatures are forecast to rise into the low 60s but the heat index temperature won't be too far removed from the actual air temperature. That's in part to the strong winds expected during the day, as well as the chance for mixing down some drier air aloft. Wind gusts Monday afternoon are expected to be between 35-40 mph. 

 So if you're heading out to any one of the Memorial Day parades around town, the biggest hazard will be the wind, followed by the heat and sun. Make sure you wear plenty of sunscreen. 

Funnel clouds with thunderstorms Thursday evening

John Mershon - Forreston, IL

 Thunderstorms became more numerous over northwest Illinois Thursday evening, producing gusty winds, small hail, torrential downpours and even funnel clouds. The First Warn Weather team received several pictures of funnel clouds from a thunderstorm over northwest Ogle County, and northwest of Forreston, Thursday afternoon. This also prompted the sirens to be activated across Ogle County, although there were no reports of any tornadoes.

It's possible that the funnel cloud that formed northwest of Forreston, IL may have had brief contact with the ground, but then lifted very quickly. These funnel clouds were produced from thunderstorms that were not quite as strong as the thunderstorms that produce tornadoes, known as supercell thunderstorms. However, the funnel clouds were very pronounced!

If the funnel clouds did in fact reach the ground, they would have been called landspouts. A landspout is from a non-supercell thunderstorm and usually has a very narrow, rope-like funnel cloud that forms while the thunderstorm is still growing. This type of thunderstorm has no rotating updraft, like a supercell thunderstorm does, and the spinning typically originates near the surface.

Often times we see this occur when there are smaller scale boundaries - like an old thunderstorm boundary or front. Landspouts look like tornadoes, but form in a different manner than a tornado. They also aren't known to cause a lot of damage like tornadoes. Either way, if you do see a funnel cloud or landspout it's best to seek shelter until the storm has passed. 

Scattered thunderstorms will continue through the remainder of Thursday evening. The overall strong to severe threat has diminished some, however, a few thunderstorms may continue to pose a threat for brief funnel clouds through the 9pm hour before transitioning more to a heavy rain threat through the night. A Flood Watch has been issued for Ogle, Lee and DeKalb counties until 7am Friday for the potential of some localized flooding rain.  

Two confirmed tornadoes Wednesday afternoon and evening

The National Weather Service has confirmed that two tornadoes touched down in the Stateline Wednesday afternoon and evening. The first occurred in southern Stephenson County, near the Albertus Airport, south/southeast of Freeport, IL. The second tornado occurred northwest of Beloit, WI.

The tornado southeast of Freeport touched down about a mile east/southeast of Oakdale Nature Preserve, moving south towards the Albertus Airport. Peak wind gusts with the EF-1 tornado were around 100 mph. It was 30 yards wide and on the ground for just under two miles. No injuries were reported with the tornado but it did cause significant damage to an outbuilding, destroyed a grain bin and snapped tree trunks.

The second tornado in south-central Wisconsin occurred roughly six miles northwest of Beloit, WI and had peak wind gusts of 75 mph. This tornado was rated an EF-0. It was on the ground for a little over three miles and was 50 yards wide. No injuries were reported with this tornado and it mostly picked up large branches and sheds, lofting them into the air and a few yards downstream.

 

Showers and a few storms in the forecast

Temperatures across the Stateline are back closer to a normal pattern for late May. We won’t see temperatures drop as much thanks to a warm front that will lift across our area. However, this does increase our chances for rain Wednesday and Thursday. A few stronger storms remain possible Wednesday afternoon and evening.

We will have a gusty wind from the southeast Wednesday up to 25mph. Overnight winds will continue to gust up to 30mph at times. Thursday brings slightly less breezy conditions, but winds will still gust up to 20mph in the afternoon and evening.

We had some sunshine in parts of the Stateline both Monday and Tuesday kicking off the work week, but not much sun at all will consume our skies Wednesday. We’re looking at mostly cloudy skies with rain.

Showers are already moving in west areas early Wednesday morning. This will continue off and on throughout your Wednesday so be sure to have an umbrella or the rain gear handy. There does look to be a break Wednesday night and Thursday early afternoon where there won’t be as widespread of showers. Rain will pick up in coverage when we head for mid-afternoon Thursday.

The Storm Prediction Center still has the area under a marginal risk (level 1 out of 5) for strong to severe storms later. That is a low risk but a few storms could produce some smaller hail and funnel clouds but our main threats will be gusty winds and downpours.

Memorial Day Weekend is still looking good with temperatures back to a below normal pattern. There is a chance for a few isolated showers right now but overall, the weekend looks decent but warm. We will be back to above normal temperatures by 10 or so degrees Sunday and Monday for Memorial Day.

Brief warm up ahead of weekend warmth

 

Temperatures Monday afternoon were a little below average for the end of May, but still comfortable rising into the low to mid 60s. After plenty of sunshine greeted us for the first half of the day, cloud cover has quickly moved in and will keep us mostly cloudy through the night. Temperatures Monday night will dip into the low to mid 40s.

Clouds will stick around through the day Tuesday but afternoon highs will be similar to Monday area wide, reaching the mid 60s. As both a warm front and low pressure system near the Stateline Tuesday afternoon and evening there may be a few sprinkles that dot the skies, along with a few light showers late in the day, but the majority of Tuesday will remain dry.

Showers and thunderstorms will increase in coverage as a warm front lifts into northern Illinois Wednesday morning bringing with it heavy downpours and a few embedded thunderstorms. Severe weather is not expected during that time, but a few gustier thunderstorms are possible during the afternoon to the east and southeast of Rockford as temperatures climb following the warm front.

High temperatures Wednesday afternoon actually look to be a little warmer than previous forecast, reaching at least the low 70s (closer to average). If we manage to see some sunshine during that time, middle to upper 70s are possible. But the increase in the warmth could also mean a slight increase in thunderstorms later in the day, some of which could pose a strong wind threat. 

Scattered showers will continue Thursday as low pressure is slow to depart the Stateline, but temperatures will also remain close to 70 degrees. A few lingering showers are expected Friday with a gradual warming trend towards the latter half of the holiday weekend; highs are expected to rise into the low to mid 80s Sunday and Memorial Day.   

Rain chances return midweek

 

Skies will remain dry through rest of Sunday evening as high pressure slides closer to the Stateline. The blustery northwest wind will ease allowing temperatures to fall into the upper 30s and low 40s overnight. While not expecting anything widespread, patchy frost may be possible in some of the cooler locations Monday morning. High pressure will continue to dominate our skies through the day Monday but we'll add back in the cloud cover Monday evening. Highs will reach the mid 60s.

Low pressure will slowly inch closer to the Stateline during the day Tuesday, but with dry air to overcome the first half of the day should remain dry. A few sprinkles or light showers are possible by mid to late afternoon with rain becoming more widespread Tuesday night. A few thunderstorms will even be possible Wednesday morning as both a warm front and low pressure system move in. We briefly warm close to 70 degrees Wednesday before another dip in temperatures Thursday.

Scattered rain showers are likely Thursday before turning a little more dry Thursday night and Friday. Rainfall totals during that time will range from nearly half an inch, up to an inch, between Tuesday and Wednesday night. Isolated showers and thunderstorms are then possible heading into the holiday weekend as a warm front draws near Friday night. This will help bring temperatures back into the upper 70s and low 80s Saturday, Sunday and Monday.

Below normal temperatures stick around

The below normal temperature pattern is going to stick with us for some time before we see daytime highs climb closer to an average pattern. Similar to yesterday, temperatures will only be in the lower 60s in most places. Cloud cover decreased overnight allowing temperatures to cool into the 40s in most places to start us off Sunday morning. With the wind chill factored in, it feels a few degrees cooler than our actual air temperatures.

Sunday areas picked up a little bit of rain, most places just received trace amounts. At the Chicago/Rockford International Airport 0.05” was measured. There is no rain in the forecast for the second half of your weekend as sunshine returns today with a few clouds increasing during the afternoon hours. The next chance of rain moves in Tuesday. Off and on rain showers look to last for parts of Wednesday and Thursday before we finally see a return to warmer weather and some sun.

Winds will be breezy Sunday out of the northwest from 10-15mph and gusts up to 20-25mph. Monday winds will transition out of the easterly direction, but this will not help us warm up much, yet. 

Eventually, temperatures will rise midweek with the next bigger storm we are tracking that should bring us some heavy rain in areas across the Stateline. They will fall a little bit behind a warm front Thursday, before finally coming back to near normal Friday and into next weekend.

Friday's Storm Threat, Weather Remains Unsettled into the Weekend

Friday's Storm Threat:

A lifting warm front brought temperatures back to summer-like levels on Thursday. Highs for most of our local airports peaked in the mid to upper 80s, landing between 20° to 25° warmer than temperatures felt a day prior. Unfortunately, this quick warm-up is a very brief one as a cold front will drop our daily highs down to early-April levels by the weekend. 

Over the last couple of days, models have had a tough time depicting when this cold front would pass through the region. Current thinking suggests that the frontal boundary will come through around the midday hour Friday, which will continue thunderstorm chances well into the afternoon. However, I think the best time frame for thunderstorm development will be between the mid to late morning hours. Now,  the earlier frontal passage severely restricts the atmosphere’s ability to recharge, in turn, bringing our severe threat way down once again.

Storm Outlook:

For that reason, the Storm Prediction Center again downgraded the Stateline from a Marginal Risk (level 1 of 5) to a general thunderstorm risk. Only a sliver of McHenry, Dekalb, and Lee Counties remain under the Marginal Risk as it appears a higher chance for storm development resides to our south and east. 

If anything was to become severe locally, strong winds and some hail would be the bigger concerns. Chances do remain Isolated during the afternoon and evening as the cold front marches through the region. This would mean that if you plan on attending the Rockford's first City Market of the year, you'll want to keep an eye on the radar or stay up-to-date with the forecast! Also, I recommend putting on a light jacket before you head out as temperatures will be quick to drop into the evening. 

Weekend Outlook:

Unfortunately, our weather pattern remains unsettled and turns a bit cooler for the upcoming weekend. A surge of moisture is expected to occur along the sinking frontal boundary, resulting in a round of showers and isolated thunderstorms for the second half of Saturday. 

That, along with the northwest winds behind the front, will limit highs in the lower 60s. We trade in our upcoming rain chances for some sunshine as high pressure settles in for Sunday. Despite the amount sunshine we'll see, temperatures will still be limited to the lower 60s because of an organized northwesterly wind. Sunshine remains in the forecast for the beginning of next week, with our next rain chance arriving by Tuesday.

Abnormally dry conditions remain across northern Illinois

The latest drought monitor from the National Drought Mitigation Center was released Thursday morning and continues to highlight most of northern Illinois under abnormally dry conditions. The same holds for southern and central Wisconsin, as well as the far northwest portion of the state.

Even though conditions were abnormally hot and dry over the last week, there has been no change in the percentage of the state that is considered dry. Wisconsin is still just a little over 24 percent, while Illinois is just a little over 8 percent. A big improvement from where conditions were just over the last couple of months.

The remainder of Thursday will stay dry but the chance for showers and thunderstorms will increase towards daybreak Friday as a weakening complex of storms is expected to move in from the west and northwest. Ongoing severe thunderstorms will continue to move out of Minnesota and into Wisconsin Thursday evening. An advancing cold front will slowly move closer to the Stateline Friday morning, passing through much of the region by early afternoon.

Ahead of the front showers and thunderstorms are expected to move through during the morning, bringing our highest chance for precipitation in through daybreak. Isolated thunderstorms will then be possible during the afternoon and evening as the cold front continues to pull further away from the Stateline. There remains a low risk for a few stronger thunderstorms with the heating of the day, but our highest instability will be with the storms as they move in Friday morning.  

Summer-Like Warmth Returns Ahead of Friday's Cold Front

Rainfall Check-Up:

As expected, a majority of yesterday's rain fell primarily during the morning hours. In the end, the Rockford International Airport observed .32", which was just enough to push our meteorological spring total over the 9-inch mark. 

The rain gear won't be needed much today as our weather pattern turns more summer-like for the end of the work week. Beginning with today, temperatures will jump from yesterday's chilly 60s to a warm lower 80s. Thankfully, we will be able to enjoy today's warmth as the humidity remains low. Something that couldn't be said much of last week. Expect skies to remain partly sunny with a southerly to southwesterly wind becoming organized by the afternoon. 

Severe To The West:

Thunderstorm potential today remains low as the focus will be more to our north and west along a lifting warm front. Areas across west-central Iowa, southeast Minnesota, and west-central Wisconsin have been placed under an enhanced risk (level 3 of 5) for severe weather. 

It's in these areas where all hazards are possible. A sliver of Jo-Daviess County has been placed under a Slight Risk (level 2 of 5), with areas to the north and west of Rockford being placed under a Marginal Risk (level 1 of 5). This is mainly for any thunderstorm that is able to keep it's severe characteristics as it travels or approaches the Stateline overnight. We then turn our attention to a sinking cold front which brings the severe threat to our neck of the woods by mid-day Friday.

Friday's Potential:

Now, the timing of this cold front is still uncertain. An earlier passage means temperatures won't have an opportunity to warm much, likely remaining in the low to mid 70s before dropping off Friday night. This would also mean that the risk for strong to severe storms would be lower. 

However, if the frontal boundary is slower to sweep across the region, temperatures will have a better opportunity to warm back into the low 80s and would see a slightly higher risk for a few strong storms. Right now, areas to the south and east of Rockford have been placed under a Slight Risk (level 2 of 5) for severe weather, with the remainder of the area being under a Marginal Risk. The biggest concerns with any storm that is deemed severe will be damaging winds and large hail. Temperatures then tumble into the weekend with highs for Saturday and Sunday ending up in the lower 60s! 

Brief return to summer-like temps late week

 

After several record high and record warm low temperatures were shattered last week, this week has been much different. We've once again returned back to a below normal trend with our temperatures, something that we'll continue to see through the upcoming weekend. While not too far below average (low 70s) Monday and Tuesday, temperatures were roughly ten (10) degrees below average Wednesday with highs in the upper 50s and low 60s.

Cloud cover following the rain that moved through Wednesday morning will slowly clear from west to east Wednesday night. This will allow temperatures to fall into the low to mid 50s. As winds shift back around to the south and southwest Thursday ahead of an advancing low pressure system and cold front, temperatures on Thursday will warm back into the low 80s during the afternoon. Humidity will also go up as well, but it won't be nearly as muggy as it was last week.

Southwest winds will continue Thursday night holding temperatures in the middle to upper 60s through Friday morning. Highs Friday will depending heavily on the timing of the cold front. An earlier arrival of the cold front means temperatures won't have an opportunity to warm much, likely remaining in the low to mid 70s before dropping off Friday night. This would also mean that the risk for strong/severe storms would be lower. If the front, however, is delayed and comes through more towards the afternoon then highs will warm back into the low 80s and would see a slightly higher risk for a few strong storms during that time. 

No matter what time the front comes through Friday, temperatures will fall quickly behind with highs dropping back down to only 60 degrees Saturday. There will be a few lingering showers throughout the day Saturday with drier skies expected Sunday.   

Showers Early, Warmer Times Ahead

Showers Early:

Despite the increase in cloud cover and few late-day showers yesterday, highs still managed to climb into the lower 70s. That rain chance lingers into the first half of our Wednesday as an area of low-pressure spirals into northern Illinois.

For the most part, this morning's activity should remain light in nature. However, a heavy downpour or two cannot be ruled out. Forecast models kept the chance for scattered showers into mid-day, with conditions drying out shortly after. Even when the rain comes to an end, it will leave us with a chilly afternoon as highs only peak in the upper 60s. Clouds will further decrease this evening, leaving us with a partly cloudy sky overnight. Lows look to fall into the lower 50s. 

Warmer Thursday:

By mid-day Thursday, a warm front will be sitting to our north, allowing winds across the Stateline to shift to the southwest. This will bring temperatures out of the 60s and back into the lower 80s. Along with the warmer temperatures comes low humidity as dew points remain in the upper 50s. 

Thunderstorm potential Thursday remains focused to our northwest near the surface low and the associated cold front. As of the latest Day 2 outlook, the Storm Prediction Center has a Slight Risk (level 2 of 5) for severe weather across portions of Minnesota, Wisconsin, and Iowa. They have also placed areas to the north and west of Rockford have been placed under a Marginal Risk (level 1 of 5) for severe weather) for the instance that any thunderstorm sustains it's intensity as it tracks into the area.

Severe Potential Friday: 

The severe potential locally increases into Friday as the cold front turns it's attention to the Midwest and the Great Lakes. The Storm Prediction Center placed a majority of the Stateline under a Slight Risk (level 2 of 5) for severe weather. Storms popping up along the cold front will be capable of producing strong winds and large hail. 

With "spin" in the atmosphere lacking big-time, the tornado threat will be slim to none. The only uncertainty that remains is the timing of when the cold front passes through the Stateline. One model, the GFS or American model, brought the front in shortly after sunrise. While the EURO or the European model brings the cold front in early to mid afternoon. A detail that will be hashed out over the next 24 to 48 hours. Stay up-to-date with the forecast!