FXUS63 KLOT 241713 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1213 PM 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 /18Z TAFS THROUGH 00Z SUNDAY/... Issued at 1213 PM CDT Fri Oct 24 2025 There are no aviation weather concerns for the 18Z TAF period. NW winds are occasionally flipping to NE while moving at around or below 5 kt. This may continue until an easterly direction takes hold late in the afternoon. Then expect SE to E winds largely below 10 kt through the remainder of the period. VFR is anticipated throughout the period. Doom && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago