FXUS63 KLOT 241135

AFDLOT



Area Forecast Discussion

National Weather Service Chicago/Romeoville, IL

635 AM CDT Fri Oct 24 2025



.KEY MESSAGES...



- Frost is again expected for much of the area outside of the 

  core of the Chicago metro tonight.



- Seasonable temperatures with periodic low chances (30% or

  less) of showers this weekend into next week.



&&



.DISCUSSION...

Issued at 258 AM CDT Fri Oct 24 2025



Temps near or below freezing have been common for areas outside

of the core of the Chicago metro early this morning. A surface 

high centered just north of the Quad Cities will drift eastward 

today, ultimately exiting to the east late this evening. Clear 

skies will allow temps to quickly rebound above freezing after 

sunrise, though increasing cirrus from the southwest and only 

slight moderation of the existing airmass will cap high temps 

today in the mid 50s.



Another cold night is in store tonight on the back edge of the 

departing ridge. A gradual increase in mid to upper-level cloud 

cover, especially south, will limit nocturnal cooling to some 

extent, but areas of frost can be expected for interior 

locations again tonight.



A blocked high over low pattern across the central CONUS will 

drive much of the weather for our area this weekend into early 

next week. The main upper-level low currently over the Four 

Corners region will gradually draw in Gulf moisture across the 

southern Plains and into the mid to lower Mississippi River 

Valley during this time. Meanwhile, a weak wave shifting 

southeast over the western Great Lakes will clip the area to the

northeast on Saturday. Some mid- level moisture originating 

from the upper-level low is expected to interact with the wave 

to the north, resulting in sparse showers through the day. While

much of the area will be dry through the day, have included 

slight chance PoPs during the day and into the evening.



Current indications are that the upper-level low will remain 

well south of the area Sunday and Monday, with the northern 

periphery of the system bringing some isolated showers or bands 

of light rain during this period. But again, a vast majority of 

the area is favored to remain dry for much of the period.



A trough attempting to undercut the northern ridge from this 

weekend's blocking pattern is progged to send a wave into the 

Ohio River Valley and amplify the upper-level low over the 

central Appalachians. The expansion of the deep low combined 

with a trailing trough on the western flank of the low supports 

the inclusion of at least some scattered showers in the forecast

for Tuesday into Wednesday. 



Kluber



&&



.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...

Issued at 634 AM CDT Fri Oct 24 2025



Mostly clear skies are expected during the day today with light

northwest winds (up to around 5-6 kt) turning east this 

afternoon and southeast in the evening. Wind directions may 

become variable at times overnight (under 5 kt) before returning

to a prevailing southeast direction by daybreak Saturday along 

with increasing mid and high cloud coverage.



Petr



&&



.LOT WATCHES/WARNINGS/ADVISORIES...

IL...Freeze Warning until 8 AM CDT this morning for ILZ003-ILZ004-

     ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-ILZ019-

     ILZ020-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ103-ILZ106-

     ILZ107-ILZ108.



     Frost Advisory until 8 AM CDT this morning for ILZ105.



IN...Freeze Warning until 8 AM CDT /9 AM EDT/ this morning for 

     INZ001-INZ010-INZ011-INZ019.



     Frost Advisory until 8 AM CDT this morning for INZ002.



LM...Small Craft Advisory until 10 AM CDT this morning for Gary to 

     Burns Harbor IN-Burns Harbor to Michigan City IN.



&&



$$



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