334 FXUS63 KLOT 291123 AFDLOTArea Forecast Discussion National Weather Service Chicago/Romeoville, IL 623 AM CDT Mon Sep 29 2025
.KEY MESSAGES...
- Dry and unseasonably warm daytime conditions through next weekend will lead to worsening drought.
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.DISCUSSION... Issued at 154 AM CDT Mon Sep 29 2025
A stretch of quiet weather will continue through the week as persistent ridging remains in place overhead with 500 mb heights forecast to hang out right around 590 dam.
925-850 mb temperatures today will be similar to Sunday`s which will yield highs in the upper 80s/near 90 degrees for all but our immediate lakeside locales where a midday and afternoon lake breeze will hold temperatures in the mid to upper 70s. Deeper east to northeast flow off the lake on Tuesday and Wednesday, combined with a touch of column cooling will result in highs moderating back a few degrees each day. Increased high-level moisture will also likely result in a bit more of a cirrus canopy Wednesday into Thursday.
By Friday and into the upcoming weekend, the sprawling surface high will shift east across the Mid Atlantic (and eventually offshore). A tightening pressure gradient will result in the return of southerly breezes, particularly on Saturday and Sunday. While the mid and upper-level flow will become more active over the weekend, latest indications are that any upper waves of note will remain displaced well to our north and west. Combined with developing drought conditions, this should yield little in the way of meaningful precipitation chances. Latest guidance does suggest a low potential for decaying convection to make a run at northern Illinois Saturday evening/overnight, but chances appear no higher than 15-20 percent at this point.
Carlaw
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.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/... Issued at 623 AM CDT Mon Sep 29 2025
There are no aviation weather concerns for the 12Z TAF period:
Expect light and variable winds this morning until a lake breeze moves across mid-afternoon turning winds to E largely just below 10 kt. Winds then go light NE for tonight. VFR can be expected throughout the period.
Doom
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.LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None.
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