FXUS63 KLOT 201847

AFDLOT



Area Forecast Discussion

National Weather Service Chicago/Romeoville, IL

147 PM CDT Fri Mar 20 2026



.KEY MESSAGES...



- Unseasonably mild spring-like temperatures continue through 

  Saturday.



- Much cooler weather returns with a cold front on Sunday, and 

  persists into early next week.



&&



.DISCUSSION...

Issued at 147 PM CDT Fri Mar 20 2026



A cold front continues to work southward across the area early 

this afternoon. However, with the lack of a real cold push in 

its wake, conditions remain unseasonably mild (mid 60s to the 

70s) area-wide early this afternoon. However, this will change 

for areas near Lake Michigan later this afternoon as the low-

level flow flips onshore with a lake breeze. As this occurs 

after 2 or 3 this afternoon, temperatures will quickly drop off 

into the 40s and 50s, coldest along and near the lakeshore.



On Saturday, another cold front and area of low pressure will 

shift southward into the Upper Midwest following the quick 

eastward passage of a surface high across the Great Lakes 

tonight. This front will be moving across our area into early 

Sunday morning. However, prior to its arrival, a quick return to

breezy and unseasonably mild southwesterly winds across our 

area for Saturday. Accordingly, Saturday is by far looking to be

the best day of the weekend as temperatures top out in the 70s 

under mainly sunny skies. Also, the offshore flow will also 

curtail lake breeze development, thus resulting in the mild 

conditions extending all the way to the lakeshore. 



Conditions will remain mild Saturday night in advance of the 

approaching cold front. However, conditions will quickly turn 

chilly following the cold frontal passage early Sunday morning 

as breezy north-northeasterly winds develop. This will 

especially be the case for areas north of the Illinois and 

Kankakee Rivers, where high temperatures for the day are 

expected to occur in the morning, with temperatures quickly 

falling into the lower 40s near the lake, and into the mid 40s 

and 50s across interior parts of northern IL. These colder 

temperatures are also likely to be accompanied by gusty winds up

to 30 mph, a lower level deck of stratus and possibly a period 

or two of light rain.



Broader WNW flow across the northern CONUS will take hold 

across much of next week, with a continued series of waves 

crossing somewhere across the Great Lakes region. Cooler but 

seasonable conditions will persist Monday as high pressure 

passes across the area. However, a compact wave removed from the

stronger WNW flow aloft is progged to pass just southwest of 

the area on Tuesday and may brush the area with some cloud cover

and maybe even a few widely scattered showers. Otherwise, dry 

conditions and warming temperatures are anticipated into the 

midweek period ahead of the next approaching cold front. This 

cold front looks to move across our area sometime around 

Thursday of next week, with a period of cooler weather to follow

for the end of the week.



KJB



&&



.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...

Issued at 1226 PM CDT Fri Mar 20 2026



Key Aviation Messages for the current TAF period:



- A lake breeze is expected at Chicago terminals this afternoon

  switching wind directions to the northeast.



VFR conditions are expected through the forecast period with no

precipitation. Winds will be around 10 to 15 knots each 

afternoon. The only challenge is the direction. Prevailing winds

this afternoon will be out of the northwest. A lake breeze is 

expected to develop this afternoon and move inland switching 

Chicago terminals over to the northeast. Winds will diminish 

overnight and turn to the east before settling in the southeast 

around or just after daybreak. As the winds return to 10 knots 

in the afternoon, they'll veer to the southwest.



DK



&&



.LOT WATCHES/WARNINGS/ADVISORIES...

IL...None.

IN...None.

LM...None.



&&



$$



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