923 FXUS63 KLOT 102324 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 624 PM CDT Thu Apr 10 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 /00Z TAFS THROUGH 06Z FRIDAY/... Issued at 624 PM CDT Thu Apr 10 2025 Forecast concerns for the terminals... - MVFR ceilings this evening A couple of shortwave disturbances will continue to pivot through northern IL and northwest IN this evening allowing BKN to OVC MVFR ceilings to prevail especially near Lake Michigan. While there has also been some scattered showers across southern WI with these disturbances, recent radar trends do show the showers weakening and moving away from the terminals. Therefore, no precipitation is expected tonight. Once the disturbance pivot through after midnight, clouds should gradually rise to the 3500-4000 ft level and scatter out through Friday morning. However, some SCT to BKN diurnal VFR cumulus are expected Friday afternoon. Otherwise, expect winds to remain out of the northeast through Friday evening with speeds generally in the 6-12 kt range. Wind directions will become more westerly behind a frontal boundary late Friday evening (after 03z) with speeds easing to around 5 kts to close out the forecast period. Yack && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago