Rochester Illinois Weather Forecast Discussion

641
FXUS63 KILX 092322
AFDILX
Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
622 PM CDT Thu Oct 9 2025
.KEY MESSAGES...
- There is a low probability (20-40% chance) of temperatures
  dropping below 38 degrees along/east of the I-57 corridor
  tonight. As a result, patchy frost is expected in this area.
- A weak cold front will trigger a few light showers on
  Friday...primarily along/west of I-55. Rainfall amounts will
  remain under 0.10.
&&
.SHORT TERM...(Tonight through Friday)
Issued at 225 PM CDT Thu Oct 9 2025
A sprawling ridge of high pressure extending from Quebec
southwestward to the lower Mississippi River Valley will
continue to control the weather...resulting in another chilly
night across central Illinois. Based on the position of the ridge
axis, winds will be lightest across the Wabash River Valley
tonight. 12z NBM/HREF both suggest a 20-40% chance of temperatures
dropping below 38 degrees along/east of I-57. Given the nearly
calm winds and resulting ideal radiational cooling conditions,
have undercut numeric guidance by several degrees and continued
the mention of patchy frost across the east-central counties.
Further west, S/SE return flow will gradually strengthen
overnight...with an increase in mid/high clouds noted ahead of an
approaching cold front. Overnight lows will range from the middle
30s near the Indiana border to the middle 40s in the Illinois
River Valley.
A cold front currently poised upstream across the Dakotas will
approach the Mississippi River by Friday morning. A ribbon of
moisture advecting northward ahead of the boundary will help boost
precipitable water values from less than 0.50 currently to
1.25-1.50. As a result, several CAMs are now suggesting showers
will form along the front late tonight across Iowa into northern
Missouri, then spill eastward into west-central Illinois Friday
morning. The general trend will be for any morning showers to
gradually dissipate and decrease in areal coverage as they push
further eastward across the parched soils of central Illinois.
Have therefore focused low chance PoPs (20-40%) along/west of I-55
during the morning...with a 20% chance or less further east during
the afternoon and evening. Any rain that occurs will be quite
light...perhaps up to 0.10 in the Illinois River Valley. Given the
increased cloud cover, highs will remain in the 60s across the
northern third of the KILX CWA...with lower 70s noted further
southeast.
Barnes
.LONG TERM...(Saturday through Next Thursday)
Issued at 225 PM CDT Thu Oct 9 2025
Once the weak front passes, a return to mild and dry weather is
anticipated this weekend. Highs will generally reach the lower to
middle 70s each day.
After that, upper ridging will build over the Midwest and the
boundary will get shunted back northward by early next week. Some
models are suggesting a few showers may develop on Monday/Tuesday:
however, the NBM remains dry at this point. The main weather story
will be the warming temps...as temps get back into the lower 80s
by Monday.
Barnes
&&
.AVIATION...  (For the 00z TAFs through 00z Friday Evening)
Issued at 622 PM CDT Thu Oct 9 2025
Primarily VFR conditions are expected for the upcoming 24 hours,
however a cold front will bring a line of scattered showers into
the area for a few hours late Friday morning into Friday
afternoon. Any MVFR conditions look to be sparse, but appear to
have the best chance at KBMI for which a PROB30 was included.
Winds E-SE up to 6 kts overnight, becoming SSW 7-11 kts by
13Z-17Z.
37
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS ILX Office Area Forecast Discussion