369 FXUS63 KLOT 110532 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1232 AM CDT Fri Apr 11 2025 .KEY MESSAGES... - The upcoming weekend will feature warmer temperatures and otherwise pleasant springtime conditions. && .DISCUSSION... Issued at 227 PM CDT Thu Apr 10 2025 Through Saturday: Surface high pressure will dominate across the western Great Lakes region for Friday into Saturday. Accordingly, a period of tranquil weather is expected both days. Temperatures both days will remain the coolest near the Lake Michigan shore (highs in the 40s) due to persistent onshore flow. However, inland portions of northern IL and northwestern IN will experience warmer temperatures. Readings are expected to top out in the low to mid 50s Friday afternoon, albeit under partly cloudy/partly sunny skies resulting from a developing diurnal cumulus deck. Even warmer temperatures are then slatted for Saturday as the surface flow turns southerly along the western periphery of the exiting surface high. This will allow for readings to top out into the lower 60s across inland sections of northern IL. KJB Saturday Night through Thursday: Warm air advection is expected to kick up across the region Saturday night into Sunday along an increasing southwesterly low- level jet developing in advance of low pressure setting up over the central Plains. Ultimately, this will set the stage for a breezy and mild day across our area on Sunday as a low-level thermal ridge advects overhead. While there does look to be a decent amount of cloud cover around during the day Sunday, temperatures in this air mass should have no problem warming into the mid to upper 60s. Slightly cooler conditions could persist right along the the far northeastern IL lakeshore, however, especially if wind directions are slow to shift to an offshore component. The threat of rain Saturday night into Sunday overall looks low. Nevertheless, there is the potential (about 20% chance at this point) for a few showers (maybe even a storm or two given some steeper mid-level lapse rates) late Saturday night into Sunday morning as the nose of the low-level jet and better moisture transport shifts overhead. While this activity could linger into early Sunday morning, most areas and much of the day looks to be rain free at this point. On Monday as the central Plains low tracks northeastward into the Upper Great Lakes, in advance of the parent mid/upper trough, an accompanying cold front will shift southeastward across our area during the early portion of the day. Given the potential early day passage of this front, and most of the low-level moisture looking to quickly be shunted off to our southeast, much of the shower and storm threat with the front may end up largely across eastern sections of IL into IN. As such, our chances for showers and storms remain low for much of northern IL (~20%). Otherwise, expect winds to turn west-northwesterly and become quite gusty (35+ mph) in the wake of the cold frontal passage Monday afternoon. A period of cooler weather (highs in the 50s) is likely Tuesday into Wednesday of next week as a surface high briefly settles across the region. KJB && .AVIATION /06Z TAFS THROUGH 12Z SATURDAY/... Issued at 1232 AM CDT Fri Apr 11 2025 There are no significant aviation forecast concerns for the current TAF period. Winds will remain out of the north to northeast through tomorrow afternoon with magnitudes between 5 and 15 kts (highest during the late morning and afternoon). While ~3000 ft ceilings may be observed at GYY over the next few hours, VFR conditions are otherwise expected to prevail with skies generally trending clearer with time. Surface high pressure settling into the region this evening will lead to light/calm winds and clear skies (save for maybe a few passing tufts of cirrus) tonight into Saturday morning. Ogorek && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago