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891
FXUS63 KILX 281032
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
532 AM CDT Tue May 28 2024

.KEY MESSAGES...

- Scattered storms (20-30% chance) will develop this
  afternoon/evening and be capable of producing gusty winds.

- High pressure takes control for the latter half of the week,
  with mild and dry weather Wednesday and Thursday.

- Rain chances return Fri PM (west of I-55) into Saturday (area-
  wide). Severe storms are not expected. There is a 25-40% chance
  of exceeding 0.25" of rain through Sunday morning.

&&

.SHORT TERM...  (Through Late Tonight)
Issued at 155 AM CDT Tue May 28 2024

Early Tues AM, upper level troughing remains in place over the
upper Midwest/Great Lakes region, while a 991-mb sfc low was over
eastern Canada. Today`s forecast is practically a repeat of
Memorial Day. Another shortwave, currently evident in satellite
imagery over ND/MN, will dig towards the local area by this
afternoon, leading to scattered t-storm development.

Forecast soundings once again show steep low/mid level lapse
rates, with an inverted-V profile below the cloud base that will
support gusty winds. In a similar environment on Monday, storms in
our area did produce a few instances of at least 45 mph wind
gusts (measured at KBMI and KCMI). The 28.00z HREF probs, smoothed
to account for spatial and temporal differences among individual
CAMs, show a 20- 40% chance for gusts over 40 mph with the storms
today. Some small hail is also possible with these storms, but
instability values are relatively weak (less than 500 J/kg). The
timing of these storms will also be quite similar to Monday,
moving in from the NW around 4 PM and winding down by late
evening.

Erwin

.LONG TERM...  (Tuesday through Sunday)
Issued at 155 AM CDT Tue May 28 2024

No significant forecast changes to Wed-Thur, which should feature
great weather as broad sfc high pressure takes control across the
Midwest. High temps will generally be in the mid 70s, while
dewpoints will be near 50F on Wed, then into the 40s on Thurs.
Forecast soundings and the Cu-rule suggest scattered to broken
diurnal Cu on Wed, so sky cover was increased to 40% (as opposed
to the 25% provided by the model blend), but as drier air advects
in from the northeast on Thurs skies will be mostly clear.

Guidance is coming into better agreement regarding the timing of
the pattern shift, with the latest models showing the upper ridge
being shunted east by Fri PM as a weak shortwave approaches from
the west. This will result in the return of precip to the area Fri
PM, with the better chances being west of I-55. Instability looks
weak, so this precip is more likely to be rain than
thunderstorms, but it`s hard to completely rule out a few rumbles
at this time of year. That wave, and the associated precip
chances, shift east on Saturday, and while the exact timing may
shift some over the coming days the expectation is that all of the
area will see a rain chance in the Fri PM-Sat time frame. The
probability of exceeding 0.25" of rain through Sun AM is 25-40%.

Into the weekend and beyond, a zonal upper pattern will allow for
more disturbances to progress across the central CONUS, resulting
in additional precip chances into next week. At least through
next Monday, the prospects of severe storms appears low.
Temperatures gradually warm through the long term forecast period,
with highs reaching the mid 80s by Sun-Mon.

Erwin

&&

.AVIATION...  
-- Changed Discussion --
(For the 12z TAFs through 12z Wednesday Morning)
Issued at 615 AM CDT Tue May 28 2024

VFR conditions will be predominant through the period. Diurnal Cu
will develop around 4-5kft today. Scattered thunderstorms (20-30%
coverage) are expected during the late afternoon/evening. Brief MVFR
ceilings and isolated strong wind gusts (around 35 knots) are
possible with the storms. Northwest winds will prevail through the
period, with gusts around 18-20 knots during the day.

Erwin
-- End Changed Discussion --

&&

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

$$