(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

(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

(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

(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

(11:30AM - 11/10/20) A storm system moving through the region on today will bring a low end threat for severe t'storms to much of Northern and Central Illinois.

​Summary...
With this update we have upgraded severe t'storm probabilities across much of Northern and Central Illinois, to level 2 severe t'storm risk (limited). The overall thinking from previous updates is unchanged...And the upgrade in probability is due to increasing confidence.

A broken line of showers and t'storms has developed this morning along an advancing cold front, across Eastern Iowa and Missouri. This line is expected to rapidly push northeastward across much of the state, this afternoon through early tonight. Upwards of a level 2 (limited) severe t'storm threat is expected to exist with this activity, across much of Northern and Central Illinois. A strengthening storm system will be moving through the region, accompanied by a strong 110KT jet streak. This will be juxtaposed to reservoir of dew points in the low 60's, great shear, and great forcing...The only negating factor is limited insatiability, less than 1000J/KG. This high shear/low instability environment will be favorable for some severe t'storm threat...with damaging winds, small hail and an isolated tornado possible.

​Below is the severe t'storm forecast for this morning - tonight.

JP

(7:00AM - 11/10/20) A storm system moving through the region today will bring a period of high winds to the state, this morning through tonight.

Summary...
A strengthening storm system moving through the region today will bring a period of high winds to the state, this morning through tonight. High winds aloft, characterized by a low level jet of up to 65KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-50MPH will be likely this morning through tonight, across a large portion of the state. Strong winds will be southerly this morning into this afternoon, ahead of the storm system...Eventually becoming northwesterly on the backside of the storm system, this evening into tonight.

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

JP

(8:15PM - 11/9/20) A storm system moving through the region on Tuesday will bring a low end threat for severe t'storms to much of Northern and portions of Central Illinois.

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

A few earlier day scattered showers and isolated t'storms will be possible Tuesday morning into early Tuesday afternoon. However, the main focus will come a bit later...As a broken line of showers and t'storms is expect to develop along an advancing cold front, across Eastern Iowa, Missouri and Western Illinois Tuesday afternoon. This line is expected to rapidly push northeastward across much of the state, Tuesday afternoon through Tuesday evening. A level 1 (minimal) severe t'storm threat is expected to exist with this activity, across much of Northern and portions of Central Illinois. A strengthening storm system will be moving through the region, accompanied by a strong 110KT jet streak. This will be juxtaposed to reservoir of dew points in the low 60's, great shear, and great forcing...The only negating factor is limited insatiability, less than 1000J/KG. This high shear/low instability environment will be favorable for an isolated severe t'storm threat...with damaging winds, small hail and an isolated tornado possible should any t'storm become severe.

​Below is the severe t'storm forecast for Tuesday morning - Tuesday night.

JP

​(7:00PM - 11/9/20) A storm system moving through the region on Tuesday will bring a period of high winds to the state, Tuesday morning through Tuesday night.

​Summary...
A strengthening storm system moving through the region on Tuesday will bring a period of high winds to the state, Tuesday morning through Tuesday night. High winds aloft, characterized by a low level jet of up to 65KT will be in place. Ample mixing is expected, which will transport higher winds to the surface. Wind gusts of 35-50MPH will be likely Tuesday morning through Tuesday night, across a large portion of the state. Strong winds will be southerly Tuesday morning into Tuesday afternoon, ahead of the storm system...Eventually becoming northwesterly on the backside of the storm system, Tuesday evening into Tuesday night.

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

JP

(1:00PM - 11/9/20) A storm system moving through the region on Tuesday will bring a low end threat for severe t'storms to much of Northern and portions of Central Illinois.
​

Summary...
A few earlier day scattered showers and isolated t'storms will be possible Tuesday morning into early Tuesday afternoon. However, the main focus will come a bit later...As a broken line of showers and t'storms is expect to develop along an advancing cold front, across Eastern Iowa, Missouri and Western Illinois Tuesday afternoon. This line is expected to rapidly push northeastward across much of the state, Tuesday afternoon through Tuesday evening. A level 1 (minimal) severe t'storm threat is expected to exist with this activity, across much of Northern and portions of Central Illinois. A strengthening storm system will be moving through the region, accompanied by a strong 110KT jet streak. This will be juxtaposed to reservoir of dew points in the low 60's, great shear, and great forcing...The only negating factor is limited insatiability, less than 1000J/KG. This high shear/low instability environment will be favorable for an isolated severe t'storm threat...with damaging winds, small hail and an isolated tornado possible should any t'storm become severe.

​Below is the severe t'storm forecast for Tuesday morning - Tuesday night.

JP