FXUS63 KLOT 210547 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1247 AM CDT Sat Mar 21 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 /06Z TAFS THROUGH 12Z SUNDAY/... Issued at 1247 AM CDT Sat Mar 21 2026 - Gusty southwest winds expected this afternoon - Wind shift to gusty northeast winds and IFR (or lower) conditions expected after 06z Sunday morning. Light southeast winds will develop after sunrise this morning before winds become south-southwest and begin increasing later in the morning. By early afternoon, south-southwesterly winds will likely gust between 20-30kt until sunset (or shortly after at ORD/MDW). A cold front will move across the terminals after 06z Sunday with a brief (an hour or two) wind shift to northwest before the stronger lake enhanced front results in another shift to gusty northeast winds prior to sunrise Sunday. Low stratus is expected to follow quickly (less than an hour or so) behind the wind shift to northeast. For now, introduced IFR CIGS, but certainly possible that CIGS could be LIFR given the initially very shallow nature of this front. - Izzi && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago