​(10:45PM - 1/31/22) A major winter storm is set to significantly impact the region and state, Tuesday afternoon through Thursday evening. This winter storm is expected to produce a swath of accumulating snow/sleet/ice across the region and state during this time.

Summary...
Over the past several days model guidance has been honing in on the potential for a winter storm to affect the region and state, Tuesday through Thursday. Model guidance had been in significant disagreement regarding this storm system for the past several days. However, over the past 24 hours model guidance has come into better agreement, with an overall consensus forming. With that said, there still does continue to be some disagreement within model guidance at this time, and the overall consensus of model guidance has even shifted a bit through the day today. Stay tuned to updates over the next several days regarding this winter storm, as additional adjustments could be necessary.

​A cold front will move through the region on Tuesday, associated with a storm system moving through Southern Canada. This frontal boundary will then become nearly stationary across the region and southern half of the state Tuesday night into Wednesday. With ample advection from the south over-topping this frontal boundary, a widespread overrunning precipitation event is expected across the region and state, Tuesday afternoon through Wednesday night. Furthermore, a storm system will develop in the Southern Plains on Wednesday, and will then track through the Tennessee Valley on Thursday, and eventually into the Mid-Atlantic region on Friday. This storm system will bring a renewed push of precipitation across the region and state, Wednesday night through Thursday evening.

​Forecast...
Tuesday Afternoon - Wednesday Night, Feb 1-2nd ~ Overrunning Precipitation Event:
A cold front will move through the region on Tuesday, associated with a storm system moving through Southern Canada. This frontal boundary will then become nearly stationary across the region and southern half of the state Tuesday night into Wednesday. With ample advection of mild/moist air from the south over-topping this frontal boundary, a widespread overrunning precipitation event is expected across the region and state, Tuesday afternoon through Wednesday night. Precipitation in the form of rain will develop across portions of Missouri and Central Illinois midday Tuesday. This area of rain will expand as it further develops and pushes northeast, spreading into other portions of Northern, Central and Southern Illinois Tuesday afternoon and evening. As colder air filters in on behind the slowing cold front pushing through the state, rain will transition to a mix and snow across affected areas of Northern and Central Illinois Tuesday evening into Tuesday night. Snow will then be likely in varying intensity across a large portion of Northern and all of Central Illinois, from transition time Tuesday evening/night through Wednesday night. Periods of moderate to heavy snow will be possible at times, with more lull-like periods of lighter snows likely as well. Snowfall rates upwards of 1"+ an hour will be likely at times in the heavier periods of snow, especially Tuesday night through Wednesday afternoon. Across southern portions of Central Illinois, this is where the overall transition zone will set up with mixed precipitation being likely. Across this zone, precipitation types will range from south to north will range from freezing rain to sleet to snow. This transition zone will likely slowly shift southward through the day on Wednesday.

Wednesday Night - Thursday Evening, Feb 2-3rd ~ Main Storm System:
As the overrunning precipitation continues across the state into Wednesday night, the main storm system will also move into the region. A renewed push of precipitation will move across the state and region associated with the main storm system, Wednesday night through Thursday evening. This renewed push of precipitation, in the form of snow, will move into Western Illinois later Wednesday evening. This area of snow will then spread across Central Illinois through Wednesday night and much of the day on Thursday, before ending by Thursday evening. Periods of moderate to heavy snow will be possible at times, with snowfall rates of 1"+ an hour likely at times. Additionally, a period of windy conditions is possible Wednesday night through Thursday afternoon. During this time wind gusts upwards of 25-40MPH will be possible, which will cause blowing and drifting snow. Further south across Southern Illinois, the transition zone of mixed precipitation that had been across portions of Central Illinois Tuesday night into Wednesday evening will shift southward, settling across much of Southern Illinois Wednesday evening through Thursday afternoon. Across this zone, a precipitation types will range from south to north will range from freezing rain to sleet to snow. This transition zone will eventually change over to snow as precipitation ends Thursday evening.

In additional to the synoptic aspect to this winter storm period, conditions will be favorable for lake enhanced and lake effect snow across portions of Northeast Illinois, Wednesday evening through Thursday evening. This could enhance snowfall a bit for affected areas.

Impacts...
-An axis of of significant snowfall totals across the heart of the state, with upwards of 9-17" in the main corridor. Snowfall amounts will quickly taper north and south of this main axis, across Northern and Southern Illinois.
-An axis of significant ice accumulations of 0.10-0.50"+ across Southern Illinois.
-Significant and widespread travel impacts likely across much of the state, Tuesday evening through Thursday evening.

​Below are the snowfall and ice forecasts for this winter storm.

JP

​(11:45AM - 1/31/22) A major winter storm is set to significantly impact the region and state, Tuesday afternoon through Thursday evening. This winter storm is expected to produce a swath of accumulating snow/sleet/ice across the region and state during this time.

Summary...
Over the past several days model guidance has been honing in on the potential for a winter storm to affect the region and state, Tuesday through Thursday. Model guidance had been in significant disagreement regarding this storm system for the past several days. However, over the past 12-18 hours model guidance has started to come into better agreement, with an overall consensus solution beginning to form. With that said, there still does continue to be some disagreement within model guidance at this time, so some changes to the forecast can be expected until full agreement on the situation is reached. Stay tuned to updates over the next several days regarding this winter storm.

​A cold front will move through the region on Tuesday, associated with a storm system moving through Southern Canada. This frontal boundary will then become nearly stationary across the region and southern half of the state Tuesday night into Wednesday. With ample advection from the south over-topping this frontal boundary, a widespread overrunning precipitation event is expected across the region and state, Tuesday afternoon through Wednesday night. Furthermore, a storm system will develop in the Southern Plains on Wednesday, and will then track through the Tennessee Valley on Thursday, and eventually into the Mid-Atlantic region on Friday. This storm system will bring a renewed push of precipitation across the region and state, Wednesday night through Thursday evening.

​​​Forecast...
Tuesday Afternoon - Wednesday Night, Feb 1-2nd ~ Overrunning Precipitation Event:
A cold front will move through the region on Tuesday, associated with a storm system moving through Southern Canada. This frontal boundary will then become nearly stationary across the region and southern half of the state Tuesday night into Wednesday. With ample advection of mild/moist air from the south over-topping this frontal boundary, a widespread overrunning precipitation event is expected across the region and state, Tuesday afternoon through Wednesday night. Precipitation in the form of rain will develop across portions of Missouri and Central Illinois midday Tuesday. This area of rain will expand as it further develops and pushes northeast, spreading into other portions of Northern, Central and Southern Illinois Tuesday afternoon and evening. As colder air filters in on behind the slowing cold front pushing through the state, rain will transition to a mix and snow across affected areas of Northern and Central Illinois Tuesday evening into Tuesday night. Snow will then be likely in varying intensity across a large portion of Northern and all of Central Illinois, from transition time Tuesday evening/night through Wednesday night. Periods of moderate to heavy snow will be possible at times, with more lull-like periods of lighter snows likely as well. Snowfall rates upwards of 1"+ an hour will be likely at times in the heavier periods of snow, especially Tuesday night through Wednesday afternoon. Across southern portions of Central Illinois, this is where the overall transition zone will set up with mixed precipitation being likely. Across this zone, precipitation types will range from south to north will range from freezing rain to sleet to snow. This transition zone will likely slowly shift southward through the day on Wednesday.

Wednesday Night - Thursday Evening, Feb 2-3rd ~ Main Storm System:
As the overrunning precipitation continues across the state into Wednesday night, the main storm system will also move into the region. A renewed push of precipitation will move across the state and region associated with the main storm system, Wednesday night through Thursday evening. This renewed push of precipitation, in the form of snow, will move into Western Illinois later Wednesday evening. This area of snow will then spread across Central Illinois through Wednesday night and much of the day on Thursday, before ending by Thursday evening. Periods of moderate to heavy snow will be possible at times, with snowfall rates of 1"+ an hour likely at times. Additionally, a period of windy conditions is possible Wednesday night through Thursday afternoon. During this time wind gusts upwards of 25-40MPH will be possible, which will cause blowing and drifting snow. Further south across Southern Illinois, the transition zone of mixed precipitation that had been across portions of Central Illinois Tuesday night into Wednesday evening will shift southward, settling across much of Southern Illinois Wednesday evening through Thursday afternoon. Across this zone, a precipitation types will range from south to north will range from freezing rain to sleet to snow. This transition zone will eventually change over to snow as precipitation ends Thursday evening.

In additional to the synoptic aspect to this winter storm period, conditions will be favorable for lake enhanced and lake effect snow across portions of Northeast Illinois, Wednesday evening through Thursday evening. This could enhance snowfall a bit for affected areas.

Impacts...
-An axis of of significant snowfall totals across the heart of the state, with upwards of 7-15"+ in the main corridor. Snowfall amounts will quickly taper north and south of this main axis, across Northern and Southern Illinois.
-An axis of significant ice accumulations of 0.10-0.50"+ across Southern Illinois.
-Significant and widespread travel impacts likely across much of the state, Tuesday evening through Thursday evening.

​Below are the snowfall and ice forecasts for this winter storm.

JP

(1:30PM - 1/30/22) It is becoming increasingly likely that a winter storm will impact a large portion of the region and state this week. This winter storm will have the potential to produce an axis of accumulating snow and ice across a large portion of the state, Tuesday evening through Thursday night.

Summary...
Over the past several days model guidance has been honing in on the potential for a winter storm to affect the region and state, Tuesday through Thursday. While the potential for a winter storm to affect the state is likely, there is still uncertainty regarding track and strength of this system...Which will affect the location of the snowfall and ice axis and associated snowfall and ice accumulations. Stay tuned for further updates over the next few days regarding this winter storm.​

​What we know...
-A winter storm will move through the region Tuesday through Friday.
-An axis of accumulating snow and ice is expected across the state, with significant accumulations possible.
-Potential for lake enhanced/lake effect snow in Northeast Illinois.

What we don't know...
-The exact track and strength of the storm system.
-The exact location of the snowfall and ice axis, and expected snowfall and ice amounts.

JP

​(7:00PM - 1/29/22) A brief recap regarding the Thursday night into Friday, Jan 27-28th lake effect snow event that brought accumulating snow to portions of Northeast Illinois and the Chicago area.

Overview...
Over the days leading into this event it had appeared likely that lake effect snow would be possible Thursday night through Friday morning along the Illinois/Indiana border on into Northwest Indiana. However, Thursday afternoon and evening model guidance made a significant shift west...Suggesting the lake effect snow would set up well west than previously shown, across portions of Northeast Illinois and the Chicago area. This shift did end up becoming relating, with several inches of lake effect snow having occurred across portions of Northeast Illinois and the Chicago area.

JP

(3:30AM - 1/28/22) Lake effect snow is affecting portions of Northeast Illinois and the Chicago area, bringing accumulating snow through Friday afternoon.

Summary...
Over the past few days, it had looked likely that lake effect snow would be possible Thursday night through Friday morning along the Illinois/Indiana border on into Northwest Indiana. However, Thursday afternoon and evening model guidance made a significant shift west...Suggesting the lake effect snow would set up well west than previously shown, across portions of Northeast Illinois and the Chicago area. This evening and tonight we have been watching additional model guidance come in, as well as real time observations...And all of this information continues to support the expected accumulation of lake effect snow across portions of Northeast Illinois and the Chicago area.

​Forecast...
Lake effect snow has developed over Lake Michigan and has pushed into portions of Northeast Illinois and the Chicago area tonight over the past few hours, already leading to upwards of 1-3" of snowfall accumulation for some areas. Lake effect snow is expected to continue through the rest of tonight and through Friday morning, before ending Friday afternoon. The most widespread and organized accumulating snow will be across portions of Southeastern Lake, Cook, Eastern DuPage and Northeastern Will counties. Snowfall rates of 1-3" per hour and moderate to heavy snow will be possible at times. This will also significantly impact the Friday morning rush/commute period.

Snowfall totals upwards of 4-7" within the heart of the snowfall axis, with locally higher amounts possible. Outside of the main axis in either direction, snowfall amounts will quickly taper.

​Below is the snowfall forecast for this event.

JP

​(5:00PM - 1/26/22) A period of very cold temperatures occurred across the region over the past few days, affecting portions of the state Monday night through Wednesday morning.

Summary...
An area of high pressure moved from Southern Canada Monday night, through the Northern Plains on Tuesday and then will through the Midwest and Ohio Valley on Wednesday. A shot of very cold temperatures accompanied this area of high pressure as it moves through the region, with the coldest conditions across the state having occurred across the northern half of the state.

​Recap...
​Mon Night - Tue Morning, Jan 24-25th...
Low temperatures Monday night into Tuesday morning bottomed out between 2 to -15 across Northwest and North-Central Illinois, with wind chills of -10 to -25. Across the remainder of the state, cold temperature and will chills occurred, though at slightly moderated levels.

​Tue Night - Wed Morning, Jan 25-26th...
Low temperatures Tuesday night into Wednesday morning bottomed out between -5 to -25 across Northern Illinois, with wind chills of -15 to -40. Across the remainder of the state, cold temperature and will chills occurred, though at slightly moderated levels.

JP

(8:00PM - 1/24/22) A period of very cold temperatures has settled in across the region and will affect portions of the state over the next couple of days, from through Wednesday morning.

Summary...
An area of high pressure moved from Southern Canada Monday night, through the Northern Plains today and then will through the Midwest and Ohio Valley on Wednesday. A shot of very cold temperatures is accompanying this area of high pressure as it moves through the region, with the coldest conditions across the state likely to be across the northern half of the state.

​Forecast...
Tonight - Wed Morning, Jan 25-26th...
Very cold conditions are expected tonight into Wednesday morning across the northern half of the state, where low temperatures will range from -5 to -20 and wind chills will range from -10 to -30. Across the remainder of the state, cold temperature and will chills are also expected, though at slightly moderated levels.

Recap...
​Mon Night - Tue Morning, Jan 24-25th...
Low temperatures Monday night into Tuesday morning bottomed out between 2 to -15 across Northwest and North-Central Illinois, with wind chills of -10 to -25. Across the remainder of the state, cold temperature and will chills occurred, though at slightly moderated levels.

JP

(8:00PM - 1/24/22) A period of very cold temperatures will affect portions of the state over the next couple of days, from tonight through Wednesday morning.

Summary...
An area of high pressure will move from Southern Canada tonight, through the Northern Plains on Tuesday and then through the Midwest and Ohio Valley on Wednesday. A shot of very cold temperatures will accompany this area of high pressure as it moves through the region, with the coldest conditions across the state likely to be across the northern half of the state.

​Forecast...
Mon Night - Tue Morning, Jan 24-25th...
Very cold conditions are expected tonight into Tuesday morning across Northwest and North-CentralIllinois, where low temperatures will range from -3 to -12 and wind chills will range from -10 to -25. Across the remainder of the state, cold temperature and will chills are also expected, though at slightly moderated levels.

Tue Night - Wed Morning, Jan 25-26th...
Very cold conditions are expected Tuesday night into Wednesday morning across the northern half of the state, where low temperatures will range from -5 to -20 and wind chills will range from -10 to -30. Across the remainder of the state, cold temperature and will chills are also expected, though at slightly moderated levels.

JP

(9:45PM - 1/23/22) A storm system is moving through the region tonight into Monday. This storm system will bring a period of accumulating snow across Northern and portions of Central Illinois, tonight through midday Monday.

Summary...
A weak and fast moving storm system that moved from the Northern Plains today will move through the Midwest tonight, and then through the Great Lakes on Monday. This storm system will bring a period of accumulating snow across Northern and portions of Central Illinois, tonight through midday Monday.

Forecast...
An area of snow will spread across much of Northern and portions of Central Illinois tonight. Snow will then be likely across Northern and portions of Central Illinois, overnight tonight through Monday morning, before ending by midday Monday. Snow intensity will generally vary from light to moderate for the duration of this event, with snowfall rates up to around 0.5" per hour being  possible.

Snowfall totals upwards of 1-3" are expected across Northern Illinois.

​Below is the snowfall forecast for this event.

JP

(10:45AM - 1/23/22) A storm system is expected to move through the region today into Monday. This storm system will bring a period of accumulating snow across Northern and portions of Central Illinois, tonight through midday Monday.

Summary...
A weak and fast moving storm system will move from the Northern Plains today, through the Midwest tonight, and through the Great Lakes on Monday. This storm system will bring a period of accumulating snow across Northern and portions of Central Illinois, tonight through midday Monday.

Forecast...
An area of snow will quickly spread into Northwest Illinois late this evening or early tonight. This area of snow will then spread across much of Northern and portions of Central Illinois Sunday night. Snow will then be likely across Northern and portions of Central Illinois, tonight through late Monday morning, before ending by early Monday afternoon. Snow intensity will generally vary from light to moderate for the duration of this event, with snowfall rates up to excess of 0.5" per hour expected.

Snowfall totals upwards of 1-3" are expected across Northern and portions of Central Illinois.

​Below is the snowfall forecast for this event.

JP