textproduct: Chicago

KEY MESSAGES

- Rain is expected across central IL/IN and may extend as far north as US-24 this evening and overnight.

- Above average temperatures continue through midweek then turn colder toward the end of the week.

- Periodic precipitation chances exist mid to late next week (~20-40% chance).

DISCUSSION

Issued at 300 PM CST Sat Feb 14 2026

Through Tonight:

Expansive stratus extending north of an approaching disturbance slowed diurnal warming across the area for much of the day. However, a brief southward shift in the northern edge of the clouds has allowed sun to shine over far northern Illinois intermittently where temperatures have since warmed into the lower 50s. Elsewhere temperatures are still in the mid to upper 40s and may struggle to warm much more prior to sunset. A weak lake breeze hugging the immediate lakeshore will also keep temperatures in the lower to mid 40s there.

Looking ahead to tonight, dry conditions are expected for most of the area. We are monitoring an expansive area of rain currently lifting into central Illinois. Based on the latest hi-res model trends, have held onto rain chances for locales south of US-24 where the northern periphery of the rain shield could briefly lift across. Rainfall amounts should remain light given the limited duration, under 0.15". Increasing low-level moisture in the wake of the departing system could allow for patchy fog development (well south of I-80) as temperatures cool overnight.

Sunday:

A weak mid-level short-wave will dive across the area late tonight into early Sunday morning with an associated surface trough axis turning winds northwest. This will actually lead to warmer upstream air advecting into the area on Sunday. In contrast to today's temperature forecast which was more uncertain due to the cloud cover, temperatures look to more solidly warm into the 50s across the area, including near the lakeshore. In fact, some of the warmer guidance (RAP/HRRR) suggest some areas could reach 60. An inland push of the lake breeze will cut the warmth short near the lakeshore where temperatures will quickly fall back into the 40s in the afternoon.

Monday and Tuesday:

Expansive upper-level ridging will build across the region on Monday and set the stage for the warmest day of the year so far with highs potentially in the upper 50s to lower 60s areawide (this would break record highs for Feb 16 at both Rockford and Chicago-O'Hare). As is often the case on anomalously warm days it will likely be paired with gusty southwest winds potentially gusting up to 30-35 mph in the afternoon.

Tuesday night through Wednesday morning:

The western CONUS upper trough begins to eject off the Rockies toward midweek with lee cyclogenesis expected across the northern Plains. This feature is then expected to drift east across the Upper Midwest with an expansive region of warm advective precipitation expected to develop out ahead of it. This could lead to a period of rain late Tuesday night into Wednesday morning over portions of the area (with the wintry precipitation likely remaining north of the WI/IL stateline). A brief period of elevated instability could support a few embedded lightning strikes, however, given lower confidence, opted to maintain a cap of 15% on thunder chances.

Wednesday through the end of the week:

Confidence in the details decreases in the wake of the Tuesday night system with differences in how far north the various subsequent systems track, with the local area potentially residing on either side or right along it. Opted to not make big changes to the blended guidance for now, which leans toward the warmer guidance on Wednesday with highs potentially well into the 60s (upper 60s south of I-80) with periodic low precip chances (20-40%). Temperatures then generally trend colder (and more seasonable) toward the end of the week which could feature wintry precipitation depending on where the aforementioned systems track.

Petr

AVIATION /00Z TAFS THROUGH 06Z MONDAY/

Issued at 527 PM CST Sat Feb 14 2026

No significant aviation weather concerns for the 00Z TAFs.

The terminals will remain well to the north of an area of rain and lower vis/cig conditions moving east across central IL/IN this evening in association with an area of low pressure. Main item of note for our locale is a weak surface pressure gradient and somewhat variable light winds this evening, though a southerly direction (160-190 deg) should be most favored. Winds are expected to eventually shift more southwest to west- southwest later tonight into Sunday morning, before the passage of a weak surface trough shifts winds northwest near 10 kts by midday/early afternoon. A north-northeasterly lake breeze will likely develop into northwest IN and the immediate Lake Michigan shore by mid-late afternoon, with winds eventually turning east-southeasterly at ORD and MDW Sunday evening.

Otherwise, VFR conditions are expected to prevail through the period with high clouds above FL200 this evening giving way to more scattered layers above 8-10 kft late.

Ratzer

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...None.