(8:30PM - 11/25/20) Thanksgiving is upon us, and along with it will come a quiet and seasonable weather day. High temperatures across the state will range from the mid 40's across far Northern Illinois, to the mid 50's across Southwest Illinois. Low temperatures will get down into the mid 30's to low 40's across the state, both Thursday morning and Thursday night. Partly to mostly cloudy skies are expected across much of the state, on average through the day.

From all of us at ISC, Happy Thanksgiving!

JP

(10:15PM - 11/23/20) A storm system moving through the region the next few days will bring a period of snow to Northern Illinois, tonight through midday Tuesday.

​Summary...
An area of precipitation developed across Nebraska, Kansas, Iowa and Missouri today, as warm air advection has been increasing... associated with an incoming storm system. This area of precipitation has been expanding and steadily pushing northeastward... and has spread across Central Illinois this evening and early tonight. Areas of all snow have occurred along the Illinois/Missouri and Illinois/Iowa border region of Western Illinois, while generally all rain has occurred across Central Illinois. This precipitation will continue to spread northeastward, tonight through midday Tuesday. With colder air in place as this precipitation moves through, a large amount of the precipitation will fall as snow across Northern Illinois during this time-frame. A couple hour period of snow is likely across a good portion of Northern Illinois tonight through late Tuesday morning. Beyond this time-frame, temperatures will warm into the 40's, allowing snow to change to rain and any snowfall accumulation to quickly melt. Snowfall totals will generally range from a dusting to around 1" across much of Northern Illinois. However, an area of higher snowfall totals will be possible near the Illinois/Wisconsin border and in Northwest Illinois...where a dusting to 2" of accumulation will be possible (locally higher amounts possible). Across Central Illinois, precipitation will mainly be rain...but could flip to rain/snow mix or all snow for a brief time late tonight or early Tuesday morning. Little to no snowfall accumulation is expected.

Below is the snowfall forecast for tonight through midday Tuesday.

JP

(11:45AM - 11/23/20) A storm system moving through the region the next few days will bring a period of snow to Northern Illinois, tonight through midday Tuesday.

​Summary...
An area of precipitation will develop across Nebraska, Kansas, Iowa and Missouri today, as warm air advection increases...associated with an incoming storm system. This area of precipitation will expand and steadily push northeastward...eventually spreading across portions of Central and much of Northern Illinois, tonight through midday Tuesday. With colder air in place as this precipitation moves through, much of the precipitation will fall as snow across Northern Illinois during this time-frame. A couple to several hour period of snow is likely across much of Northern Illinois tonight through late Tuesday morning. Beyond this time-frame, temperatures will warm a bit, allowing snow to change to rain and any snowfall accumulation to quickly melt. Snowfall totals will range from a dusting to 2" across much of Northern Illinois. Highest snowfall totals will be near the Illinois/Wisconsin border and in Northwest Illinois...where locally higher amounts will be possible. Across Central Illinois, precipitation will mainly be rain...but could flip to snow for a brief time late tonight or early Tuesday morning. Little to no snowfall accumulation is expected.

Below is the snowfall forecast for tonight through midday Tuesday.

JP

(7:30PM - 11/22/20) A storm system moving through the region Tuesday into Wednesday will bring a period of high winds to the state, Tuesday morning through midday Wednesday.

​Summary...
A storm system moving through the region Tuesday into Wedneesday will bring a period of high winds to the state, Tuesday morning through midday Wednesday. High winds aloft, characterized by a low level jet of 60-75KT, will be in place. Mixing depth is in question, but will likely be enough to transport some of the higher winds to the surface. Wind gusts of 35-45MPH will be possible Tuesday morning through midday Wednesday, across the state and a large portion of the region.

​Below is the high wind forecast for Tuesday morning - midday Wednesday.

JP

(7:30AM - 11/19/20) A storm system moving through the region today will bring a period of high winds to the state, early this morning through this evening.

Summary...
Previous forecast is on track, no significant changes needed...

A storm system moving through the region today will bring a period of high winds to the state, this morning through this evening. High winds aloft, characterized by a low level jet of 60-70KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-55MPH will be likely this morning through this evening, across the state and a large portion of the region.

​Below is the high wind forecast for this morning - this evening.

JP

(8:00PM - 11/18/20) A storm system moving through the region on Thursday will bring a period of high winds to the state, early Thursday morning through Thursday evening.

​Summary...
A storm system moving through the region on Thursday will bring a period of high winds to the state, early Thursday morning through Thursday evening. High winds aloft, characterized by a low level jet of 60-70KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-55MPH will be likely early Thursday morning through Thursday evening, across the state and a large portion of the region.

​Below is the high wind forecast for Thursday morning - Thursday evening.

JP

(10:45AM - 11/14/20) A storm system moving through the region today and Sunday will bring a period of high winds to the state, from later this morning through Sunday night.

Summary...
Previous forecast is on track, no significant changes needed...
​
A strengthening storm system moving through the region today and Sunday will bring a period of high winds to the state, later this morning through Sunday night. High winds aloft, characterized by a low level jet of 60-70KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-55MPH will be likely later this morning through Sunday night, across the state and a large portion of the region. Strong winds will be southerly later this morning into tonight, ahead of the storm system...Eventually becoming west/northwesterly on the backside of the storm system, later tonight into early Sunday night.

​Below is the high wind forecast for this this morning - Sunday night.

JP

(11:45AM - 11/13/20) A storm system moving through the region Saturday and Sunday will bring a period of high winds to the state, Saturday morning through Sunday night.

Summary...
Previous forecast is on track, no significant changes needed...
​
A strengthening storm system moving through the region Saturday and Sunday will bring a period of high winds to the state, Saturday morning through Sunday night. High winds aloft, characterized by a low level jet of 60-70KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-55MPH will be likely Saturday morning through Sunday night, across the state and a large portion of the region. Strong winds will be southerly Saturday morning into early Saturday night, ahead of the storm system...Eventually becoming northwesterly on the backside of the storm system, this Saturday night into Sunday night.

​Below is the high wind forecast for this Saturday morning - Sunday night.

JP

(7:45PM - 11/12/20) A storm system moving through the region Saturday and Sunday will bring a period of high winds to the state, Saturday morning through Sunday night.

​Summary...
A strengthening storm system moving through the region Saturday and Sunday will bring a period of high winds to the state, Saturday morning through Sunday night. High winds aloft, characterized by a low level jet of 60-70KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-55MPH will be likely Saturday morning through Sunday night, across the state and a large portion of the region. Strong winds will be southerly Saturday morning into early Saturday night, ahead of the storm system...Eventually becoming northwesterly on the backside of the storm system, this Saturday night into Sunday night.

​Below is the high wind forecast for this Saturday morning - Sunday night.

JP

(1:30PM - 11/12/20) A period of record warmth spanning over several days impacted portions of the region and state, November 3-10th.

​Overview....
The combination of a trough in the Western US and a ridge in place across the Central and Eastern US, brought a prolonged period of unseasonably and record warm temperatures to the state and region. Daily high temperatures were in the 70's across the state during this period, with low temperatures as mild as the 50's and 60's for much of the state for a few nights as well. New daily record high and warm low temperatures occurred for many locations across the state as well.

​Notes....
For Chicago, in addition to daily record high and warm low temperatures being broken... The low temperature of 63 on Nov 9th tied the all time record for the warmest low temperature in the month of November. Additionally, the stretch of 7 days with high temperatures of 70+ set the record for the longest such period in the month of November, as well as the latest string of such days on record in a year. There have now been 7 days that have featured a 70+ high temperature...Thus, November 2020 broke the all time record for most days with a 70+ high temperature, for any November on record.

JP