Thunderstorms likely again Thursday afternoon

 

Many locations Wednesday afternoon reached 90 degrees, with Rockford's official high topping out at 89 degrees. The afternoon heat did help fuel widely scattered thunderstorms that produced torrential downpours, frequent lightning, and even gusty winds. A severe thunderstorm warning was even issued for a portion of Rock and Walworth counties.

The radar has turned quiet Wednesday evening with skies expected to remain mostly clear to partly cloudy overnight. It's actually a fairly comfortable evening, especially in the areas that experienced the afternoon rain and where temperatures cooled as a result.

Thursday will be similar to Wednesday, temperatures soaring through the upper 80s and low 90s with a few afternoon thunderstorms. A slightly drier air mass Thursday may limit the overall coverage but look for storms to begin after 1pm/2pm, and last through sunset. Like Wednesday, torrential downpours and gusty winds will be possible. We may actually see the storms push a little further west of I-39 where storm coverage Wednesday was very isolated.

The thunderstorms were not the result of anything from above, but more so from what happened at the surface. The difference in temperature between the waters of Lake Michigan and the adjacent land caused a lake breeze to develop. As the lake breeze moved inland it caused the slightly unstable air mass to rise, resulting in thunderstorms. 

Those storms then produced outflow boundaries from rain cooled air. These boundaries produced

additional thunderstorms that slowly moved north and northwest. Because the winds aloft were so weak, the storms were not moving fast at all resulting in heavy downpours - for those who were under those storms. For others, it didn't rain at all or only a few drops of rain fell. Isolated thunderstorms will occur once again Friday, but likely remain confined to northwest Illinois. Winds on Friday will shift to the east, but it won't do much to cool us off. In fact, highs on Friday are forecast to warm into the low 90s during the afternoon.  

Heat expected to continue this week

 

Temperatures soared into the upper 80s and low 90s Tuesday afternoon. Cloud cover did increase during the late morning and afternoon for a portion of the area Tuesday. This was due to a slight increase in moisture across northeast and north-central Illinois. Sinking air over northwest Illinois left skies mostly sunny. There have been a few very spotty showers that tried to develop with the heat of the day, but the lack of any true surface moisture kept skies mostly dry. We will continue to see some cloud cover through the evening, with skies remaining partly cloudy overnight.

Highs Wednesday will warm into the upper 80s, but the degree of the heat will depend on how fast cloud cover develops during the day. There will be a slight increase in surface moisture Wednesday with afternoon dew point temperatures warming to the middle to upper 50s. With that, we may see cloud cover bubble back up a little sooner than what we did for Tuesday. Regardless, it'll still remain hot.

Highs on Thursday will warm again into the upper 80s, to near 90 degrees, with the low 90s possible Friday and Saturday. Humidity will go up slightly, but it won't be excessive. It may be just enough, though, to make it begin to feel a little more uncomfortable. Temperatures will remain warm through the weekend, only dropping slightly heading into early next week.  

Memorial Day weekend forecast

 

Temperatures this holiday weekend will feel more like mid to late June and early July, rather than late May. Under sun-filled skies Saturday high temperatures will warm into the upper 70s. We may see a little more cloud cover move in late in the day, turning skies partly cloudy Saturday night. Temperatures Saturday night will dip into the upper 40s.

Partly cloudy skies can be expected Sunday as a little moisture gets tugged into the Great Lakes from low pressure over the Southeast. No rain is expected with highs warming into the low 80s. The warming trend will continue for Memorial Day itself with temperatures in the middle 80s. Dew point temperatures should remain in the 50s which will keep humidity values a little more comfortable. That trend is expected to continue into next week, even as temperatures warm.

Deep gulf moisture will be focused across the Plains and Upper Midwest next week. This will keep the higher humidity values well west of the Stateline. Temperatures will warm, though, reaching the upper 80s, and possibly low 90s, several days next week. Dew point temperatures will also climb, but likely top out close to 60 degrees. This will keep the heat index just a few degrees above the actual air temperature. Still, with several days of high heat expected it's important to remember your heat safety precautions, especially if you're planning on spending a lot of time outdoors.

Rain chances next week look to remain low, if we see them at all, with lower moisture. There is under a 20 percent chance for a shower/storm beginning next Tuesday.

Summer-like heat returns, but humidity remains low

 

A beautiful stretch of weather is expected through the holiday weekend with temperatures warming into the upper 70s and low to mid 80s.

For Friday, it's a cooler start as temperatures have dipped into the upper 30s in a few locations. A light wind through the night may have allowed some patchy frost to develop, especially in low-lying areas.

Mostly sunny skies are expected Friday afternoon with a light breeze from the east and northeast. Highs will warm into the mid 70s. Under mostly clear skies Friday night temperatures will dip into the mid 40s. Temperatures will continue to warm through the weekend as an upper-level ridge settles in over the eastern Great Lakes and northeast. This will keep a dry air mass across the Stateline with dew point temperatures in the 40s. Highs temperatures are forecast to warm through the low to mid 80s Sunday and Monday.

The warming trend is set to continue through next week as highs reach the upper 80s by Tuesday, then possibly low 90s by the middle of the week. Winds shifting to the southeast will help pull in a little more moisture during the afternoon, but drier air mixing down from the upper levels will help keep humidity levels on the lower end. Deeper moisture will be pulled into the Plains and Upper Midwest as the summer-like heat continues.   

Gusty winds bring plenty of chills Wednesday evening

 

Temperatures Wednesday afternoon warmed into the middle and upper 70s, to low 80s. It was a little cooler than what we felt Tuesday afternoon, especially east of Rockford.

Cooler air continues to move in this evening, bringing temperatures down into the low 60s as of 8pm. Cloud cover has also increased, leaving our skies mostly cloudy through the night. As winds continue to gust around 25 mph overnight lows will fall into the low to mid 40s. There may even be a slight wind chill Thursday morning.

Skies remain mostly cloudy during the morning Thursday, but we should see a return to mostly sunny skies for the afternoon. Thursday will be our coolest day with highs reaching the middle to upper 60s, to right around 70 degrees. Overnight lows Thursday night will dip into the low 40s, with a few outlying locations possibly falling to the upper 30s. The chance of temperatures dipping that cool remains low, but it is there. Highs Friday under mostly sunny skies will warm into the middle 70s.  

Backdoor cold front Wednesday brings cools temperatures through the end of the week

 

There was quite the range in temperatures Sunday morning, from the low to mid 40s to the low 50s. Since sunrise, temperatures have warmed nicely into the low and mid 60s. The warmup continues into the afternoon with highs reaching the upper 70s. There may even be a few locations that reach 80 degrees.

Skies will remain mostly sunny with high pressure located over the Great Lakes. We may see just a few fair-weather cumulus clouds during the afternoon. The smoke from the wildfires in Canada has been pulled back north, leaving us with more blue to the sky than days past. As a weak upper-level disturbance slides through tonight (Sunday night) that may bring with it a little more smoke. This could turn our skies slightly more hazy Sunday evening/night. Overnight lows are forecast to fall back into the upper 40s.

Temperatures Monday and Tuesday will warm into the low 80s, but a backdoor cold front will quickly move down the Great Lakes Wednesday morning. This is caused by high pressure over the northeast, bringing winds across Lake Michigan.

This will turn winds to the northeast during the morning and afternoon. The timing of the front will determine just how warm temperatures get Wednesday, but it does look like the front comes through during the morning. This would keep highs in the low 70s Wednesday afternoon. Although it would be a little warmer to the west of Rockford and a little cooler to the east. A brief increase in moisture may be enough to generate a very light shower or two during the afternoon, but most will remain dry.

The northeast wind will keep temperatures in the 70s through the end of the week before warming back into the upper 70s, near 80 degrees, Memorial Day weekend.

Above average trend continues through the end of May

 Longer range outlooks continue to show a higher probability for above average temperatures across the Stateline through the end of the month. That trend may also carry over into the beginning of June. The 6-10 day outlook from NOAA's Climate Prediction Center shows much of the country at a higher probability for above average temperatures through May 29th.

The outlook for precipitation also favors a higher probability for below average precipitation over the Great Lakes, Ohio Valley, and Northeast.

While the warm and dry weather is nice, especially for those who have outdoor plans, we do need the rain. On average, we typically need an inch of rain per week throughout the summer months. This is ideal for crop and plant growth - along with the warmer temperatures.

Looking ahead into the three-month period of June, July, and August we may begin to see the pattern flip just a little bit. While there are no strong signals for whether or not temperatures will be above or below average, there are some signs that point to a slightly higher probability for above average precipitation.

Until then, the upcoming week looks pretty good if you need to cut the first crop of hay. Dry conditions will last through the weekend and early next week. There is a small chance for an isolated shower towards the middle of the week. This would be with a backdoor cold front coming in Wednesday off of Lake Michigan. Temperatures could drop into the 70s with the cooler air behind the front is strong enough.  

Hazy skies may continue Friday following cold front

 

Skies over the Great Lakes and Midwest have been filled with smoke from numerous wildfires in Canada, some burning out of control. Most of the smoke in the Stateline has remained in the upper levels of the atmosphere. But as a cold front passes through the region late Thursday night, the smoke aloft could be pushed closer to the surface early Friday morning.

An 'Air Quality Alert' has been issued for not only southern Wisconsin, but the entire state as air quality

is expected to deteriorate as the cold front moves through. Cold air is more dense than warm air, causing it to sink down closer to the surface. As this happens, the smoke that has been mostly aloft the last few days will also sink towards the surface. This could give our skies an even hazier look during the day Friday. It's also possible for there to be a little more of a smoke smell Friday. How much, or how little, we actually end up seeing - or smelling - is yet to be determined, but particulate matter concentrations are forecast to increase before cleaner air moves in late Friday. According to the Wisconsin Department of Natural Resources, the air quality index is expected to reach the 'unhealthy for sensitive groups' level later tonight and Friday.

The smoke may linger in the atmosphere, likely back in the upper levels, through the weekend and next week as our jet stream pattern remains from the northwest. This would cause the hazy/milky sky to continue into next week. 

Rain and thunder return Thursday night

 

Temperatures Wednesday afternoon warmed into the middle and upper 60s, slightly below average for mid-May. The mercury will climb once again Thursday as winds turn to the southwest during the afternoon. This will bring temperatures into the middle and upper 70s area wide.

The majority of Thursday will be dry, but hazy as smoke from wildfires in Canada continue to stream down into the Midwest and Great Lakes. Skies will turn partly cloudy by Thursday evening.

The southwest breeze will increase through the afternoon as a cold front nears from the northwest. To the northwest, from Minnesota, Iowa, and Wisconsin, rain and thunderstorms will be likely. Some of those storms could turn severe with hail and wind being the primary threats.

As the cold front sinks closer to the Stateline Thursday night cloud cover will increase. Showers will move in behind the front, after 9pm/10pm, and continue through sunrise Friday. 

A few heavier downpours are possible, especially during the overnight, but should come to an end mid to late morning. Rainfall totals will range from around a quarter of an inch to just under half an inch.   

Tumbling temperatures Tuesday evening

 

High temperatures Tuesday afternoon warmed into the upper 70s and low 80s, reaching 80 degrees in Rockford. We had sun-filled skies for most of the afternoon but now has more of a hazy look to it. This is due to smoke from wildfires in Canada getting caught in the jet stream, moving down across the Great Lakes and Midwest. More on that a little later!

As for temperatures, those are falling quickly along the lake shore of Lake Michigan in Wisconsin and northeast Illinois. Temperatures in some locations have fallen 20 (+) degrees in just a matter of 20-30 minutes! The temperature drop won't be quite as dramatic further inland (for the Stateline) but closer to sunset you'll feel the cooler temperatures as winds turn to the northeast as our numbers fall into the 60s by sunset.

Northeast winds will increase as the front passes, gusting 25-30 mph. It'll remain breezy through the night as temperatures dip into the low to mid 40s. Hazy sunshine is expected Wednesday with temperatures warming back into the upper 60s to low 70s.   

Summer warmth expected Tuesday ahead of strong cold front Tuesday evening

 Following a cool and rainy Sunday afternoon, Monday was fairly comfortable as temperatures warmed into the upper 60s and low 70s. We will continue to see cloud cover stream in from the west and southwest as showers pass to the south. No rain is anticipated Monday night.

Skies will start off cloudy Tuesday with temperatures in the middle to upper 40s. Increasing sunshine during the afternoon and warming temperatures aloft will bring highs into the upper 70s and low 80s area wide.

A strong cold front will race down Lake Michigan Tuesday afternoon and evening. This will cause temperatures to quickly drop along the lake shore in Wisconsin and Illinois. Temperatures further inland will also drop, but not as dramatic as locations to the east.

This type of a cold front is known as a 'pneumonia cold front' because of how quickly temperatures fall behind it. Along the lake shore temperatures could fall

20-25 degrees within a matter of 30-45 minutes. Closer to the Stateline the temperature drop won't be as drastic, but we will feel the chill just before sunrise, possibly falling 15-20 degrees within a couple hours.

Winds will also increase, shifting from the northwest to northeast as the front moves in. Gusts through the evening could be as high as 25-30 mph. An isolated shower or two is possible, but coverage is expected to remain very light - if we see anything at all. Skies stay mostly clear Tuesday night with temperatures dipping into the low to mid 40s. Sunshine returns Wednesday with highs warming to 70 degrees.  

Mostly dry Saturday afternoon but rain returns Sunday

 

Heavy rain fell for some Friday afternoon and evening as showers and thunderstorms moved across northern Illinois and southern Wisconsin. These formed along a warm front during the afternoon, but that front has been pushed back south Saturday morning.

This will be the focus for scattered thunderstorms, some severe, during the afternoon and evening. Drier air (briefly) moving in on the heels of a northeast breeze will leave skies mostly dry and mostly cloudy. We may see some peeks of sunshine during the afternoon as temperatures warm into the low to mid 70s.

An isolated shower/storm can't completely be ruled out, but the afternoon looks to remain mostly dry. Severe thunderstorms will remain focused from Iowa through central Illinois. We'll keep an eye on any storm that develops over Carroll, Whiteside, and Lee counties as a low-end risk for a strong storm or two is possible.

Rain chances will increase Saturday night as the warm front lifts back into northern Illinois. Moisture also increases and this will lead to a few heavier downpours through sunrise Sunday. Embedded thunderstorms are possible as well. As the warm front tightens up during the night an east wind will increase. Cooler air aloft will settle into the Stateline, and this could help hold temperatures in the upper 50s during the afternoon! It'll be a raw and cool Mother's Day.

Scattered showers will last through 3-5pm with skies beginning to dry out Sunday evening. High pressure sinking down the Great Lakes will cause our skies to clear out Sunday night and temperatures falling into the upper 30s and low 40s. There will still be a little breeze during that time, so frost doesn't appear to be too much of a concern. Rainfall totals Sunday could be as high as one inch in some locations.   

Rain showers move out, Fog continues Monday night

 

Light rain and drizzle will continue Monday evening with skies remaining mostly cloudy overnight. Rainfall totals Monday ranged between half an inch to three quarters of an inch, with slightly higher totals to the west.

Clouds are thinning out over northwest Illinois where temperatures have warmed into the low 60s but remain in the 50s further east where drizzle and low clouds remain. Fog has also been an issue throughout the day reducing visibility down to only a couple miles in some locations but is improving.

Fog is expected to develop once again overnight as low-level moisture lingers. Locally dense fog will be possible around, and shortly after, sunrise so be careful on the morning commute. Drier air coming in from high pressure to the north will help clear our skies and warm temperatures back into the low 70s. Dry skies will remain through Thursday night before the next chance of rain returns.  

Patchy fog early Sunday morning

 

Showers and thunderstorms remained mostly south of the region Saturday night, bringing heavy rain and severe thunderstorms to southeast Iowa and west-central Illinois. This led to mostly cloudy skies overnight, but those clouds are beginning to clear from west to east.

Lingering low-level moisture has caused fog to develop, mostly to the west and north of Rockford. Visibility has fallen to under a mile in south-central Wisconsin and across far northwest Illinois.

This fog isn't expected to last too long into the morning. Skies will then become mostly sunny before a little cloud cover moves back in mid-day.

Severe storms possible Saturday evening/night, then again Sunday

 

Skies are beginning to dry out early Saturday morning following a few steadier showers overnight. While skies are starting off mostly cloudy, we should see a few sunny breaks during the early afternoon. There are currently two clusters of thunderstorms on radar we're keeping an eye on: one moving through Waterloo, IA and the other in northeast Missouri. The storms over Iowa are currently moving to the northeast, towards southwest Wisconsin, and weakening. The storms in northeast Missouri are likely to remain well to the southwest, tied to better instability and near a surface warm front. Locally, a few spotty showers and drizzle remain possible this morning.

Temperatures will slowly warm through the low 60s during the morning, reaching the low 70s by the afternoon. The risk for severe thunderstorms may then increase with the arrival of a warm front later Saturday evening and overnight.

These storms, most likely remaining elevated, would pose the risk for large hail through the night. But if any storm gains enough strength, we could see a secondary risk for damaging wind gusts and an isolated tornado. That risk may reside a little further to the west and southwest of northern Illinois.

Saturday's overnight activity should be ending by Sunday morning with skies turning partly cloudy by the afternoon. Following the passage of the warm front, temperatures are expected to rise quickly into the mid 80s. Dew points will also be on the rise, nearing 60 degrees by the afternoon. This will actually make it feel a little humid outside. 

An isolated storm or two can't be ruled out during

the afternoon Sunday, especially if any outflow boundaries interact with the warm front. We continue to keep an eye on the storm risk going into Sunday evening and overnight which could again produce a risk for severe thunderstorms, but also heavy rainfall. Rainfall totals between Saturday and Sunday night could be between one to two inches.

It's important to remain weather aware today, especially tonight, and then again Sunday. We'll continue to keep you updated throughout the weekend.    

Thunderstorm chances return for the weekend, but many dry hours ahead

 

Temperatures Thursday afternoon warmed into the low 70s thanks to an abundance of sunshine and breezy south wind. High pressure will hold strong through the evening before shifting to the east during the night. Temperatures Thursday night will drop into the upper 40s, rising once again into the mid-70s Friday afternoon.

The majority of Friday will be dry, but we will see a little more cloud cover during the afternoon. That is the result of low pressure passing through central and southern Illinois. That low is currently moving through the southern Plains. Drier air throughout most of the afternoon will keep mainly dry skies, but a shower or two can't be ruled out over northwest Illinois and southwest Wisconsin after 6pm/7pm. A few isolated showers will then be possible area wide Friday night.

The 70-degree warmth will continue Saturday as a ridge of high pressure builds in during the afternoon. We may see a little more cloud cover, but it looks to be another dry day. The chance for showers and thunderstorms will begin to increase slightly Saturday evening, lasting into Sunday morning. Severe weather is not expected, but a strong storm or storm could contain quarter sized hail. 

A warm front lifting north into Wisconsin Sunday will bring temperatures into the upper 70s, possibly evening low to mid 80s! But the warm-up could come with the risk for an isolated strong/severe storm during the afternoon. The forcing aloft remains fairly weak, and our atmosphere looks to stay capped during the afternoon. If, however, any outflow boundaries become strong enough to break the cap we could see an isolated storm or two during the afternoon. If that happens there is a low-end chance for the storms to turn severe. While the threat remains low for Sunday, it is a day we need to keep an eye on. 

The storm chance increases slightly Sunday night into Monday with temperatures holding in the 70s, middle and upper 70s, through the middle of next week.     

Cloud cover increases Tuesday afternoon

Clouds have filled back in Tuesday afternoon following mostly sunny skies earlier in the day. The sunshine did help to warm temperatures into the upper 50s and low 60s, with Rockford reaching 60 degrees. Still a little below average but moving in the right direction. 

Skies will remain mostly cloudy through sunset with partly cloudy skies expected overnight. Gusty northwest winds will continue through the evening but should begin to weaken with the arrival of high pressure during the overnight.

Temperatures will be chilly, falling into the low 30s overnight. Patchy frost is possible but is not expected to be widespread due to the breezy winds. Sunshine will return Wednesday with temperatures warming into the low to mid 60s. 

Wind Advisory until 7pm

 

A WIND ADVISORY remains in effect for Jo Daviess, Carroll, and Whiteside counties until 7pm Monday. Northwest winds have been gusting 40-45 mph throughout the afternoon.

The strong wind gusts will ease some Monday evening but remain around 30-35 mph overnight. Winds will pick back up during the afternoon Tuesday, gusting to 35 mph. As high pressure moves in Tuesday evening winds will begin to ease but

remain from the northwest through Wednesday.