420
FXUS63 KILX 170111
AFDILX

Area Forecast Discussion...Updated
National Weather Service Lincoln IL
811 PM CDT Tue Jul 16 2024

.KEY MESSAGES...

- Potential for widespread rain continues into this evening south
  of I-70, but otherwise showers with a few thunderstorms should
  be spotty, mainly south of I-72 this evening.

- A stretch of below normal temperatures and mostly dry conditions
  arrives Wednesday and continues through the weekend.

&&

.UPDATE...
Issued at 810 PM CDT Tue Jul 16 2024

This evening, a diffuse trough is in place over central Illinois
stretching from near Chicago southwest towards the lower Illinois
River Valley. This would be the main area to keep an eye on for some
isolated showers or storms through late this evening, but with
diminishing instability, increasing convective inhibition, and
overall weak forcing, coverage is expected to be isolated at best.
Have lowered PoPs mainly into the slight chance / isolated
category ahead of the aforementioned trough axis (along and
southeast of I-55). Otherwise, outside of this low chance for
precip, it appears we will be kicking off a needed stretch of dry
weather across central Illinois for the next several days.

Deubelbeiss

&&

.DISCUSSION...
Issued at 333 PM CDT Tue Jul 16 2024

A poorly defined cold front is currently stalled out near the
Illinois River and will finally sweep southeastward across the
remainder of central and southeast IL tonight, with a few clusters
of thunderstorms still possible ahead of the front possible south
of I-70, providing potential for additional widespread rain,
possibly locally heavy. Precipitable water analyzed by SPC
mesoanalysis still indicates a corridor of 2 to 2.3 inches of
precipitable water from central MO into southeast IL, which
supports the heavy rain potential as shortwave disturbances
propagate through the base of a trough over the Midwest. The main
concern will be for a few corridors of repeated
thunderstorms/training where flow parallels ongoing thunderstorms,
while heavy rainfall from the past 24 hours, generally 1 to 3
inches near and south of I-70, has saturated soils in the area. A
flash flood watch continues until 1 AM in this area.

Conditions Wednesday should be dry aside from a slight chance of
showers near the departing cold front south of I-70. High pressure
will then settle into the region Wednesday night into the weekend,
providing dry conditions. High pressure will weaken early next
week, with a weak trough over the central U.S. that should allow
moisture to return to the area along with chances for showers and
thunderstorms.

Temperatures will also drop off considerably the next several days
as a cooler air mass follows tonight`s front, with highs
expected in the upper 70s to lower 80s and lows dipping into the
upper 50s to lower 60s for the next several days. First, though,
tonight`s lows should range from mid 60s to around 70 south of
I-70 as moisture has yet to scour out from the humidity of the
last few days.

37

&&

.AVIATION...  (For the 00z TAFs through 00z Wednesday Evening)
Issued at 631 PM CDT Tue Jul 16 2024

Precip chances will settle south of the terminals late this
evening and overnight. Winds should generally stay out of the
northwest this evening and tonight, but may be variable at times.
Will have to monitor for some fog or low stratus development late
tonight into Wednesday morning particularly at DEC/CMI, but
confidence is low at this time to include in the forecast. A
modest north breeze of 10-12kt with some gusts approaching 20kt
is expected Wednesday.

Deubelbeiss

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$