Area Forecast Discussion
Issued by NWS Central Illinois

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000
FXUS63 KILX 190822
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
322 AM CDT Tue Mar 19 2024

.KEY MESSAGES...

- Elevated fire danger across central Illinois today due to wind
  gusts of 35-45mph and low relative humidity values.

- Another hard freeze expected Wednesday night when overnight lows
  once again dip into the middle 20s.

- Significant storm system slated to bring widespread precipitation
  to the region early next week.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 321 AM CDT Tue Mar 19 2024

07z/2am surface analysis shows a 1026mb high centered over the
Deep South while a cold front drops southward through the Upper
Midwest. The pressure gradient between these two features will
tighten sufficiently to produce strong/gusty W/SW winds across
central Illinois this morning. In addition, NAM/GFS both depict a
45-50kt 925mb jet streak developing ahead of the front from
Missouri into the southern Great Lakes. While a strong nocturnal
temperature inversion will initially be in place, once the depth
of the mixed layer increases, some of this higher momentum air
will be transported to the surface from late morning through
mid-afternoon. 00z Mar 19 HREF shows a 100% chance of gusts over
30mph across the entire KILX CWA and a high probability (50-70
percent chance) of gusts exceeding 40mph everywhere north of the
I-70 corridor. Thanks to the strong winds and relative humidity
values dropping into the 30s, an elevated fire risk will develop
today. Burning should be avoided as fires may quickly spread out
of control. The winds will gradually decrease by late afternoon,
then will drop to 10mph or less by evening after the cold front
passes. High temperatures will top out in the upper 50s and lower
60s, then will drop into the lower to middle 30s tonight as a
cooler airmass returns. Plenty of sunshine is expected on
Wednesday: however, below normal temperatures in the 40s are
expected across much of the area...with lower 50s south of I-70.
As winds diminish, another cold night is on tap Wednesday night
when low temperatures bottom out in the middle 20s. Precautions
will once again need to be taken in order to protect any sensitive
outdoor vegetation from the freezing temperatures.

Barnes

.LONG TERM...(Thursday through Monday)
Issued at 321 AM CDT Tue Mar 19 2024

Two weather systems will impact central Illinois in the extended.
The first will spread light precipitation into the area Thursday
night into Friday...while the second more significant system will
bring widespread heavier precip early next week.

A northern stream short-wave trough will drop southeastward out of
Canada and skirt into the Great Lakes on Friday. WAA ahead of the
wave will help light precip develop late Thursday night into
Friday morning...with the highest probabilities (50-70%) focused
along/northwest of a Rushville to Bloomington line in closer
proximity to the strongest lift/deepest moisture. With overnight
lows dropping into the lower to middle 30s, atmospheric profiles
support a rain/snow mix north of the I-74 corridor. No snow
accumulation is expected.

High pressure will bring cool/dry weather to the region Friday
night through Saturday before the second system begins to approach
from the southwest by late in the weekend. Model solutions still
vary on timing, but all solutions track low pressure through the
Midwest during the Monday/Tuesday time frame. While some previous
solutions had spread light precip into at least the western half
of central Illinois by late Saturday night into Sunday morning,
the latest trends seem to be slowing precip onset and thus reducing
the chance of a period of wet snow as it begins. Current forecast
features high chance PoPs for a rain/snow mix along/west of I-55
Sunday morning, but these may need to be reduced or removed
entirely if trends continue. Strongest forcing is focusing from
Sunday night through Monday night when widespread showers and
perhaps a few thunderstorms will develop. It is still too early to
pinpoint exact amounts, but early indications suggest rainfall
over 1 inch across the entire area.

Barnes

&&

.AVIATION...  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1223 AM CDT Tue Mar 19 2024

Main aviation forecast challenge will be the strong wind gusts
later this morning into the afternoon. Models depict a 40-50kt
925mb jet streak developing in advance of a cold front from
Missouri across central Illinois by mid-morning. A strong nocturnal
inversion will initially be in place: however, as the mixed layer
deepens...some of this higher momentum air will be transferred to
the surface. Most numeric guidance suggests W/SW gusts in the
30-35kt range from around 15z through 20z before winds veer to
W/NW and the gusts slowly begin to decrease by late afternoon.
Winds will then decrease to 10kt or less after sunset.

Barnes

&&

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

$$


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