Area Forecast Discussion
Issued by NWS Central Illinois

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562
FXUS63 KILX 311941
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
241 PM CDT Sun May 31 2026

.KEY MESSAGES...

- Above normal temperatures are likely to persist into mid June,
  with highs generally in the 80s. Humidity values are expected
  to increase late this week into early next week.

- Widely scattered showers and storms are possible through
  Monday, with the best chance (30-40%) being south of a
  Galesburg to Decatur to Lawrenceville line late tonight into
  Monday morning. Dry conditions are expected Tuesday through
  Thursday.

&&

.DISCUSSION...
Issued at 230 PM CDT Sun May 31 2026

Scattered showers affected areas from I-55 nw today, with
isolated showers lingering north of I-74 and lifting northward
as they continue to diminish. A small MCS was over east central
MO south of St Louis and drifting ESE toward southern tip IL
and this convection should pass south of CWA into this evening
as it weakens too. Another disturbance/MCS to develop over
southern Iowa/northern MO tonight and track se over southern
half of IL late tonight into Mon morning. The highest chances of
convection appears to be over southern IL, while 30-40% pops in
our southern/sw counties and slight pops northern/ne CWA. SPC
Day1 and Day2 outlook though Monday night keeps marginal risk
sw of CWA where more unstable air mass in sw IL into MO and
closer to frontal boundary south and sw of IL. Lows tonight in
the lower 60s. The CAMs show much of convection passing se of
CWA during midday and afternoon hours on Monday as skies become
partly to mostly sunny Monday afternoon. Highs Monday in the
lower 80s, with mid 80s over west central IL.

The Omega Block will reposition itself a bit during mid week
with large mid/upper level low over New England and mid Atlantic
States and northern Rockies into southern CA while narrow upper
level ridge from Texas into the upper MS river valley and
Ontario Province Tue with upper level ridge shifting over IL on
Wed. Large Canadian high pressure to settle southward from
Hudson Bay into the Great Lakes on Tue, into the Ohio river
valley Wed and mid/southern Atlantic States on Thu. Dry/fair wx
expected over central/se IL Mon night through Thu night with a
fair amount of sunshine Tue/Wed and partly to mostly sunny Thu.
Highs Tue in the lower 80s, warm back into the mid/upper 80s Thu
as SSW flow starts and also will increase humidity late this
week. A summerlike pattern takes shape over IL late this week
into early next week with warm and more humid conditions
prevailing along with daily chances of showers and
thunderstorms Friday through Monday/June 8th, starting in
central IL Fri and in southeast IL too on Saturday.

Climate Prediction Center (CPC) Day 8-14 Outlook for June 8-14
has 55-60% chance of above normal temperatures over central/se
IL and 33-40% chance of above normal precipitation. CPC Risk of
Hazardous Temperatures shows Slight Risk (20-40%) of Extreme
Heat over IL from June 8-11th.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1250 PM CDT Sun May 31 2026

An area of scattered showers had impacted PIA and BMI airports
at midday and should lift ne of these terminals next hour or so.
VFR conditions still prevailed with these showers and generally
expected VFR conditions to continue next 24 hours thru 18Z/1 pm
Monday. Isolated showers may linger over central IL into tonight
but coverage appears limited. Another cluster of showers and
isolated thunderstorms tracking southeast out of MO and southern
Iowa could impact central IL airports from 11-16Z Monday
especially along I-72 and have prob30 groups for SHRA. If
isolated thunderstorms occur may see possible brief MVFR
conditions. ESE to SE winds 5-9 kts this afternoon to be around
5 kts tonight and ENE winds 5-10 kts Monday.

&&

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

&&

$$

KEY MESSAGES...07
DISCUSSION...07
AVIATION...07