861
FXUS63 KILX 121816
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
116 PM CDT Tue May 12 2026

.KEY MESSAGES...

- Gusty winds exceeding 30 mph today and Wednesday may cause
  localized blowing dust, significantly reducing visibility.
  These impacts are most likely north of Interstate 70 and east
  of the Illinois River, but can occur anywhere agricultural
  fieldwork is active.

- A notable warming trend is expected this weekend, coinciding
  with daily thunderstorm chances. Severe weather potential is
  trending upward for the period spanning Friday through Monday.

&&

.DISCUSSION...(through next Tuesday)
Issued at 114 PM CDT Tue May 12 2026

Midday Water Vapor (WV) imagery reveals a potent mid-level
shortwave trough currently digging across the Upper-Mississippi
Valley region. This synoptic feature and its associated surface
low are forecast to continue tracking southeastward into the
Great Lakes region this evening, driving a trailing cold front
southward across the Central Illinois forecast area. Recent
observational trends indicate a relatively narrow band of clouds
and precipitation accompanying this front. However, our 12Z
RAOB data highlighted a notably dry lower troposphere,
suggesting that the limited showery activity may struggle with
sub-cloud evaporation and could fail to reach the surface in
numerous locations.

Central Illinois remains under a low-end severe weather risk
this evening, primarily for isolated strong wind gusts. The
environment is characterized by very steep low-level lapse
rates, measured at greater than 9C/km. This thermodynamic
profile, coupled with strong boundary layer mixing, supports the
potential for efficient downward momentum transfer. As such,
any convection that manages to develop ahead of the front could
mix down isolated wind gusts reaching 50 mph. Instability is
marginal, with low CAPE, moderate shear, and weak overall
forcing. Model soundings indicate a high-based, shallow nature,
with the equilibrium level barely extending above the 0C
isotherm. While the low freezing level (less than 10 kft AGL)
offers marginal support for small hail, the limited CAPE in the
hail growth zone (-10C to -30C) mitigates this risk
significantly. Overall, the lingering residual capping layer and
weak forcing will limit widespread development. Quantitative
Precipitation Forecast (QPF) trends from the latest 12Z HREF
LPMM remain low, predicting a highly variable field of trace
amounts to a localized maximum of one-quarter inch of rain
through tonight.

The most impactful hazard this afternoon remains the potential
for blowing dust, active ahead of and along the cold front. The
aforementioned steep low-level lapse rates will support frequent
wind gusts exceeding 30 mph through the late afternoon,
coinciding with peak agricultural field work. Compounding this,
data from the Illinois State Water Survey`s WARM program shows
relatively dry 2-inch soil moisture levels (generally 30%). This
combination necessitates the continuation of a Blowing Dust
Advisory through 7 PM this evening, as localized areas of
significantly reduced visibility are highly probable where field
work is in progress.

The main band of precipitation will sweep south of the region
overnight, ushering in dry conditions Wednesday and Thursday. A
prominent upper-level ridge and associated surface high pressure
system will build across the Midwest, reinforcing a period of
cold-air advection and noticeably cooler temperatures for
Wednesday. Winds will once again be breezy as steep low-level
lapse rates extend higher into the column (up to 700 mb).
Efficient boundary layer mixing will likely support occasional
wind gusts exceeding 30 mph. Given the generally light rainfall
amounts expected tonight, the environment for blowing dust will
likely persist, making a follow-up Blowing Dust Advisory
possible for Wednesday.

Medium-range guidance indicates a significant and sustained
surge of Gulf of Mexico moisture initiating Friday and
continuing into early next week. This synoptic shift will advect
a warmer and markedly more humid airmass into the Midwest,
increasing the potential for more frequent organized convection.
Through Monday, the resulting thermodynamic and kinematic
profiles appear increasingly favorable for daily severe weather
potential, particularly across the Lower Ohio and Mid-
Mississippi River Valleys. Furthermore, the concern for blowing
dust may resurface across Central Illinois over the upcoming
weekend as strengthening southerly winds accompany the warming
trend. However, the ultimate impact on visibility will be
governed by the timing and total accumulated rainfall that
manages to occur during the latter portion of the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1202 PM CDT Tue May 12 2026

VFR conditions will persist through this TAF period. This
despite a cold front and an attendant line of scattered showers
pushing across the regional terminals this evening. The rain is
being handled by a PROB30 group, largely between 00z-06z.
Confidence and coverage of isolated thunderstorms remains too
low to mention in the TAFs, but there is a non-zero chance of
thunder this evening as the front pushes through.

Otherwise, breezy conditions likely serve as the main aviation
impact, with sustained winds from the south this afternoon
around 15 kts and occasional gusts near 30 kts. Winds will
diminish and veer northwest overnight behind the front. Breezy
northwest gusts may then return late Wednesday morning.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Blowing Dust Advisory until 7 PM CDT this evening for
ILZ027>031-036>038-040>057-061.

&&

$$

KEY MESSAGES...MJA
DISCUSSION...MJA
AVIATION...MJA