textproduct: Chicago

KEY MESSAGES

- Cooler and continued dry conditions today and Monday, with shower and storm chances returning on Tuesday.

DISCUSSION

Issued at 158 AM CDT Sun May 10 2026

High pressure will drift across the western Great Lakes through Monday as deep troughing over eastern Canada edges eastward. This will set the stage for a seasonably cool, but dry and mostly clear period for the area. Continued deep diurnal mixing will promote sporadic gusts to 25(20) mph or higher and RH values under 30(35) percent this afternoon (Monday afternoon), resulting in a brief period of elevated brush fire conditions each afternoon.

With high pressure nearing from the northwest and dry conditions noted by PWATs under 0.4 inches, another unseasonably chilly night with some patchy frost for outlying areas of far northern Illinois is possible late. Some mid-level cloud cover associated with a wave/elongated trough currently over southern Manitoba will cross the area tonight and may be keep temps just warm enough to limit coverage of frost. Conditions appear too marginal to issue a Frost Advisory for counties including and north of the I-88 corridor.

A modestly strong trough tracking southeastward over the Boundary Waters early Tuesday will brush the area to the north with WAA-induced showers during the morning, followed by a potential axis of showers and some thunderstorms associated with a cold front Tuesday afternoon into the evening. Will need to monitor for a low-end isolated strong storm risk during this time as a decent kinematic field compensates for marginal mid- level lapse rates and a somewhat dry low-level profile.

High pressure and a return to seasonably cool and dry conditions will return Wednesday and Thursday. The broader flow across North America is then progged to transition into a more active northern stream across the CONUS, with increasing rain/storm chances and potentially a period of seasonably warm conditions beginning as early as Friday and especially late next weekend into the following week.

Kluber

AVIATION /06Z TAFS THROUGH 12Z MONDAY/

Issued at 1239 AM CDT Sun May 10 2026

Key Messages:

- A renewed surge of east-northeast winds expected early this morning, possibly briefly gusting up to 18 KT at ORD and MDW just after the 06Z, before abating through the predawn hours.

- Winds to settle into a northwesterly direction (all sites expect GYY) mid to late this morning, with some gustiness (up around or just above 20 kt) developing this afternoon.

- Northeast winds return at all sites by early evening.

The only notable weather concern through the period, as noted above, revolve around wind trends. Winds are currently nearly calm across much of the area. However, there is currently another surge of northeasterly winds currently dropping southward into far northeastern IL. This is expected to result in resurgence of northeasterly winds at the Chicago area terminals in the 06-07 timeframe. A few gusts of 17 to 20 kt may accompany the initial surge of winds, but speeds are expected to abate through the overnight hours, with generally light (5 kt or less) and variable winds anticipated by daybreak this morning. Thereafter, winds will settle into a northwesterly direction by mid to late this morning (expect at GYY, where north-northeasterly winds will persist today), then become gusty up around 21 kt this afternoon. Finally, as wind speeds abate early this evening, expect directions to shift back to the east-northeast as surface high pressure quickly builds into the western Great Lakes. Easterly onshore winds are anticipated to persist with this surface high through Monday.

KJB

LOT WATCHES/WARNINGS/ADVISORIES

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