Area Forecast Discussion
Issued by NWS Central Illinois

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037
FXUS63 KILX 150432
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1132 PM CDT Fri Jun 14 2024

.KEY MESSAGES...

- Seasonably hot and humid weather is on tap for next week. Heat
  index values will peak at or above 100 degrees from Sunday
  afternoon through Monday afternoon before readings settle back
  into the middle to upper 90s for the remainder of the week.

&&

.UPDATE...
Issued at 818 PM CDT Fri Jun 14 2024

A few mid-level clouds, tied to shortwave energy lifting atop the
ridge axis, shouldn`t be enough to interrupt an otherwise stellar
diurnal cooling setup. Our 00z sounding is impressively dry, and
there`s no reason to think overnight temperatures won`t crash into
the upper 50s in many areas. In a similar manner, the diurnal
bounce Saturday afternoon could be equally impressive as
temperatures surge back into the upper 80s beneath a thin layer of
high clouds.

MJA

&&

.SHORT TERM...(Tonight through Saturday)
Issued at 309 PM CDT Fri Jun 14 2024

Weak cold front has settled southward into the Ohio River Valley
this afternoon, allowing a slightly cooler and less humid airmass
to filter into central Illinois. 19z/2pm dewpoints have dropped
into the 50s everywhere along/north of I-70...making things feel
quite a bit more comfortable than yesterday. As high pressure
builds into the region tonight, radiational cooling of the drier
air will allow low temperatures to fall into the upper 50s and
lower 60s. The high will shift off to the east on Saturday:
however, boundary layer flow will maintain an easterly component
and dewpoints will stay in the 50s. High temperatures will reach
the middle to upper 80s.

Barnes

.LONG TERM...(Sunday through Next Friday)
Issued at 309 PM CDT Fri Jun 14 2024

A short-wave trough will track from Colorado/New Mexico
northeastward into the western Great Lakes on Sunday. This feature
will remain just W/NW of central Illinois, with scattered
showers/storms perhaps getting as close as the Mississippi River
Saturday night into Sunday. Have maintained a dry forecast at this
time, but may need to add slight chance PoPs across the Illinois
River Valley if the trailing trough axis gets closer than
currently expected. As the wave lifts into the Great Lakes, a warm
front will get pulled northward through central Illinois, causing
winds to veer to the SW by Sunday afternoon. This will push air
temperatures into the lower to middle 90s and dewpoints well into
the 60s. Resulting heat index values will reach the upper 90s to
around 100 degrees. Even higher heat index readings of 100-105 are
expected on Monday as upper heights rise and air temperatures
reach the middle 90s.

As deep-layer southwesterly flow develops, a swath of moisture
will flow northward from the western Gulf of Mexico. Both the GFS
and ECMWF suggest widely scattered diurnal convection both Monday
and Tuesday afternoons. As diurnal cloud cover increases, air
temperatures will likely be a couple degrees cooler by Tuesday,
resulting in heat index values generally below 100. After that, a
hot and humid week is ahead with temperatures in the 90s through
next Friday.

Barnes

&&

.AVIATION...  (For the 06z TAFs through 06z Saturday Night)
Issued at 1115 PM CDT Fri Jun 14 2024

VFR conditions to prevail the next 24 hours with mainly scattered
high clouds, though a few diurnal clouds around 5,000 feet may
form toward midday Saturday. Winds will shift to the south-
southeast Saturday morning and increase to around 8-10 knots.
Evening model guidance is hinting at some potential LLWS
developing over the northwest half of Illinois Saturday evening,
which may be an issue for KPIA by the end of the forecast period.

Geelhart

&&

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

$$