520 FXUS63 KILX 181745 AFDILXArea Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1245 PM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Hot and dry weather will continue until Saturday, with daytime highs topping out in the upper 80s to lower 90s. Temperatures looks to cool down by the middle of next week.
- A slow moving upper level low will bring daily chances (20 to 40 percent) for showers and thunderstorms early next week. The best chance (50-70%) for showers and thunderstorms comes Sunday into Monday. Precipitation looks to be generally light.
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.UPDATE... Issued at 1055 AM CDT Thu Sep 18 2025
Minor updates to the forecast for slight chances of showers and thunderstorms over far nw CWA (Galesburg to Rushville west) this afternoon and having 20-40% of convection from Peoria and Springfield west by overnight, with likely pops just west of Knox Fulton and Schuyler counties. Much of area will remain dry though through tonight, with another hot day unfolding with a fair amount of sunshine, light winds and highs in the lower 90s. This will be the 9th consecutive day with above normal highs since Wed/Sep 10th.
A 574 decameter 500 mb low over central SD was embedded in a mid/upper level trof from eastern MT into central parts of SD/NE and western KS. The cutoff upper level low stays near central SD while the trof axis shifts slowly eastward toward the IA/NE and MO/KS border by this evening. Brunt of convection has been over nw MO, southeast Iowa into far west central and nw IL (including far western Schuyler county) at late morning. The CAMs shower isolated convection from Galesburg to Rushville west/nw this afternoon and getting a bit further east over the IL river valley by overnight.
07
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.DISCUSSION... Issued at 217 AM CDT Thu Sep 18 2025
Another day, another round of hot and dry weather, but there`s a small bit of good news: light winds should help keep fire danger in check with the drought in place. This pattern is expected to change as a slow weather system moves into the region this afternoon, bringing a daily chance of showers and thunderstorms that will last into next week. A drought-busting rain is not expected, though. There is a 30-50% chance of getting more than an inch of rain by next Wednesday morning from the LREF. Sunday into Monday looks to be the best probability of showers and thunderstorms, with with POPs of 50-70%.
A more progressive, potentially wetter, pattern looks to be setting up, as there is a signal for another low pressure system to move through the forecast area by mid week. This will bring additional rain chances, maybe even a strong storm or two (??). This system looks to be more potent than this weekend`s system.
Highs will be in the upper 80s to low 90s through Saturday, before a welcome cool down into the low to upper 80s arrives for the start of the new week. Overnight lows will stay in the 60s through Monday night. Then, overnight lows in the mid to upper 50s take over through the extended. It looks like the temperatures will drop closer to normal (mid 70s-ish), but staying slightly above normal, late in the week.
Copple
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.AVIATION... (For the 18z TAFs through 18z Friday Afternoon) Issued at 1245 PM CDT Thu Sep 18 2025
VFR conditions should continue across the central IL terminals through 18Z/1 pm Friday. Nearby weak high pressure ridge will continue to influence central IL through Friday morning with light and variable winds next 24 hours. A cold front over central WI pushes into northeast IL overnight and lifts slowly back north on Friday. Meanwhile a weak 1012 mb low pressure in east central SD with a frontal boundary into eastern NE/KS to weaken as it pushes eastward into far west central IL Fri morning. Its convection should stay west of PIA and SPI through midday Friday, though will likely see broken mid/high clouds affect those airports especially overnight into Fri morning.
07
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.ILX WATCHES/WARNINGS/ADVISORIES... None. &&
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NWS ILX Office Area Forecast Discussion