Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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956 FXUS63 KILX 192347 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 547 PM CST Wed Nov 19 2025 .KEY MESSAGES... - Low clouds and patchy fog will once again be a concern tonight into early Thursday morning. - Rain will lift into the region Thursday evening, with the highest rainfall totals expected to be south of a Quincy to Terre Haute line where there is currently a high (50-80%) chance of exceeding 0.50"; source 12z REFS. - A sharp cold front will push through by the middle of next week, likely sending overnight temperatures into the 20s (60-90% chance), and perhaps making you reconsider running that turkey trot; source 13z NBM. && .DISCUSSION... Issued at 144 PM CST Wed Nov 19 2025 Low stratus and patchy fog are the primary concerns for tonight, likely reducing visibility once again. This idea is supported by the synoptic pattern, which features low-level warm advection and mid-level shortwave energy interacting with a sharpening 925-850 mb baroclinic zone. Occasional sprinkles cannot be ruled out later tonight, either, especially as cloud ice nuclei return. QPF appears limited to a couple hundredths or less in any one spot, though. A brief period of subsidence then works into west central and southwest Illinois Thursday morning ahead of the next frontal system, which will pivot out of the southern Plains and into our area Thursday evening into Friday. While clouds are unlikely to scatter out, we should see ceilings lift quite a bit throughout Thursday morning. Rain is expected to move into our region later Thursday evening. However, uncertainty exists regarding the northern extent of this rain, mainly due to the influence of dry air pushing down from the Upper Midwest. And to that point, QPF also remains somewhat uncertain. The highest amounts appear to favor areas south of a Quincy-to-Terre Haute line, where convective chances are also highest. Leaning on the latest REFS LPMM QPF output, something in the realm of 0.25" - 1.5" seems reasonable, with amounts quickly tapering off to 0.10" or less north of such a line. Dry and mild weather shall return by the weekend as the frontal system departs and high pressure builds across the central US. Afternoon temperatures look on track to warm into the mid-to-upper 50s each Sunday and Monday as low-level warm advection occurs beneath an amplifying ridge axis. Attention then turns to the Tuesday-Wednesday timeframe as yet another frontal system ejects out of the southern Plains and lifts across our area. Convective chances and moisture return ahead of the system look limited, perhaps tamping down QPF in the 0.1"-0.5" range. The bigger story with this frontal system will be the whipsawing temperatures, with a sharp cold front expected to move through on Wednesday, ushering in blustery north winds and causing overnight lows to bottom-out in the 20s for your early morning turkey trot. MJA && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 547 PM CST Wed Nov 19 2025 Low clouds continue to blanket central Illinois late this afternoon: however, ceilings have improved to MVFR at KPIA/KSPI. Based on HRRR/RAP forecast soundings, think ceilings will gradually lower back to IFR across the board after 05z. Minor visby reductions are present nearly everywhere and with a moist boundary layer and nearly calm winds, it appears fog will become thicker/more widespread tonight. The most consistent lower visbys of 3-5 miles have generally been focused along/north of I-74 from KBMI to KCMI. Several models including the HRRR/RAP/GFSLAMP suggest visbys will lower across this area over the next few hours...with the fog persisting through mid-morning Thursday. As such, have lowered visby to 1 mile at KCMI after 03z and at KBMI after 04z. Elsewhere have gone with 2-3 mile visbys from late evening through 15z Thursday. While the fog will dissipate toward midday, low ceilings will persist through the entire day. Given a S/SE wind of 5-10kt, think there will be enough mixing to raise ceilings to MVFR across the board by afternoon. Other than patchy drizzle tonight, any significant precip will hold off at the TAF sites until Thursday night into Friday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$