922
FXUS63 KILX 130520
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1220 AM CDT TUE OCT 13 2026
KEY MESSAGES
- RECORD-BREAKING HEAT CONTINUES THROUGH TUESDAY AFTERNOON, WITH
HIGH TEMPERATURES REACHING THE UPPER 80S TO LOWER 90S.
- A MARGINAL RISK (LEVEL 1 OF 5) FOR SEVERE THUNDERSTORMS EXISTS
TUESDAY NIGHT. SOME STORMS WILL BE CAPABLE OF PRODUCING
LOCALIZED DAMAGING WIND GUSTS AND HAIL.
- UNSETTLED WEATHER TUESDAY NIGHT THROUGH THURSDAY BRINGS
PERIODS OF WET WEATHER, WITH A 60 TO 80 PERCENT CHANCE OF 1
TO 2 INCHES OF EVENT TOTAL RAINFALL.
- A SHARP COLD FRONT TRANSITIONS THE REGION TO MUCH COOLER
CONDITIONS LATE WEEK INTO THE WEEKEND, BRINGING A POTENTIAL
FOR EARLY MORNING FROST BOTH SATURDAY AND SUNDAY.
DISCUSSION
ISSUED AT 1222 PM CDT MON OCT 12 2026
STRONG LOW-LEVEL WARM AIR ADVECTION REMAINS ESTABLISHED ACROSS
THE MIDWEST UNDER A BUILDING UPPER-LEVEL RIDGE. MID-LEVEL HEIGHT
RISES AND PERSISTENT SOUTH-SOUTHWESTERLY SURFACE WINDS GUSTING
UP TO 25 MPH WILL PUSH HIGH TEMPERATURES INTO THE UPPER 80S AND
LOWER 90S THIS AFTERNOON, LIKELY BREAKING DAILY HIGH
TEMPERATURE RECORDS. UNSEASONABLY WARM CONDITIONS PERSIST
THROUGH TUESDAY AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH.
HIGHS ON TUESDAY AGAIN TOP OUT IN THE UPPER 80S TO LOWER 90S,
ROUGHLY 20 DEGREES ABOVE SEASONAL NORMS. RECORD HIGHS REMAIN
SUSCEPTIBLE TO BEING BROKEN ACROSS CENTRAL AND SOUTHEAST
ILLINOIS. HIGH RESOLUTION GUIDANCE SHOWS THE FRONT WORKING INTO
THE CENTRAL CWA THROUGH TUESDAY AFTERNOON, AND CAMS DEPICT A FEW
POST-FRONTAL SHOWERS/SPRINKLES OVER THE NORTHWEST CWA. TO
ACCOUNT FOR THIS, ADDED SOME 20 POPS FOR THE GALESBURG AND
PEORIA AREAS.
CONVECTIVE INITIATION OCCURS TUESDAY EVENING INTO TUESDAY NIGHT
AS A LEAD SHORTWAVE TRACKS NORTHEAST TOWARD THE REGION. HREF
GUIDANCE SHOWS MUCAPE VALUES BUILDING TO 1000-1500 J/KG PAIRED
WITH 0-6KM BULK SHEAR OF 30-40 KNOTS. ML/AI SEVERE GUIDANCE,
ALONG WITH THE SPC DAY 2 OUTLOOK, MAINTAIN A MARGINAL RISK
(LEVEL 1 OF 5) FOR CENTRAL AND WESTERN PORTIONS OF THE FORECAST
AREA. PRIMARY CONVECTIVE HAZARDS FEATURE ISOLATED SEVERE WIND
GUSTS UP TO 60 MPH AND LARGE HAIL UP TO QUARTER SIZE.
THE FRONTAL BOUNDARY STALLS IN THE AREA WEDNESDAY INTO THURSDAY,
BECOMING ORIENTED PARALLEL TO UPPER-LEVEL SOUTHWEST FLOW AS
MORE SHORTWAVE ENERGY EJECTS FROM THE TROUGH TO OUR WEST. DEEP-
LAYER MOISTURE SURGES ALONG THE BOUNDARY, WITH PRECIPITABLE
WATER (PWAT) VALUES REACHING 1.75-2.00 INCHES, EXCEEDING THE
95TH PERCENTILE FOR MID-OCTOBER. HIGH-RESOLUTION ENSEMBLE
FORECASTS (HREF) AND MEDIUM-RANGE GUIDANCE (ECMWF, GEFS, AND
ECMWF-AI) SUPPORT A FEW ROUNDS OF RAIN AND EMBEDDED
THUNDERSTORMS, WITH SIZABLE BREAKS, WEDNESDAY AND THURSDAY. WPC
EXCESSIVE RAINFALL OUTLOOKS HIGHLIGHT A MARGINAL RISK FOR HEAVY
RAIN ACROSS CENTRAL AND SOUTHEAST ILLINOIS BOTH DAYS. ENSEMBLE
GUIDANCE (LREF) YIELDS HIGH CONFIDENCE (60-80% CHANCE) FOR EVENT
TOTAL RAINFALL EXCEEDING 1 INCH, WITH LOCALIZED TOTALS UP TO 2
INCHES. SOME SPREAD IS NOTED IN THE FOOTPRINT OF HEAVIER
RAINFALL DURING THIS PERIOD, WITH RECENT GUIDANCE TRENDING THE
HIGHER VALUES TO THE NORTHWEST SECTIONS OF THE CWA.
A SHARP AIRMASS CHANGE ARRIVES FRIDAY AS AN EXPANSIVE CANADIAN
SURFACE HIGH PRESSURE SYSTEM BUILDS INTO THE PLAINS AND MIDWEST.
THE GFS/GEFS CONTINUES TO BE A COLD OUTLIER AMONG THE GUIDANCE
SUITE, SHOWING TEMPERATURES SEVERAL DEGREES COLDER THAN THE
PREFERRED NBM. NONETHELESS, STRONG COLD AIR ADVECTION ON FRIDAY
WILL KEEP HIGHS BELOW NORMAL IN THE LOWER 60S, ALONG WITH GUSTY
NORTHWEST WINDS. THE FIRST FROST OF THE SEASON WILL BE IN PLAY
THIS WEEKEND, THOUGH THIS WILL LIKELY HINGE ON THE EXACT
POSITION OF THE RIDGE AXIS. CONFIDENCE IN THE RIDGE AXIS BEING
OVERHEAD DURING THE EARLY MORNING HOURS FOR CALM WINDS AND
WIDESPREAD FROST FORMATION IS LOW, BUT WITH THE COLD AIRMASS IN
PLACE, LOWS IN THE 30S ARE LIKELY BOTH SATURDAY AND SUNDAY
MORNING.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1220 AM CDT TUE OCT 13 2026
REGIONAL DOPPLER WIND PROFILES CURRENTLY SHOW A 40-45 KNOT LOW
LEVEL JET AT 2,000 FEET ACROSS CENTRAL ILLINOIS. THIS WILL
SHIFT SOUTHEAST AHEAD OF AN INCOMING COLD FRONT, AND IS
EXPECTED TO WEAKEN BETWEEN 09-12Z. SURFACE WINDS WILL AVERAGE
AROUND 10 KNOTS OR SO THROUGH THE MORNING, DIMINISHING SOME NEAR
KPIA AS THE FRONT GETS CLOSER AND SLOWS DOWN.
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD, WITH MAINLY HIGH
BASED CLOUDS. GETTING INTO TUESDAY EVENING, A GENERAL LOWERING
OF CEILINGS WILL TAKE PLACE AS SHOWERS AND THUNDERSTORMS BEGIN
TO MOVE IN FROM THE WEST. BEST CHANCE OF THUNDER APPEARS TO BE
AT KPIA/KSPI TOWARD MID TO LATE EVENING, AND WILL INCLUDE A
PROB30 GROUP AT THESE SITES FOR TSRA AND POTENTIAL MVFR
VISIBILITIES WITH THEM.
CLIMATE
ISSUED AT 1220 AM CDT TUE OCT 13 2026
RECORD HIGH TEMPERATURES:
LOCATION TUESDAY LATEST 90 DEG. HIGH
======== ======= ===================
BLOOMINGTON 91/1899 OCTOBER 15, 1899
CHAMPAIGN 86/1989 OCTOBER 14, 1899
CHARLESTON 87/2017 OCTOBER 15, 1897
DECATUR 90/1899 OCTOBER 15, 1938
JACKSONVILLE 91/1899 OCTOBER 30, 1950
OLNEY 93/1928 OCTOBER 22, 1953
PEORIA 88/1899 OCTOBER 15, 1897
SPRINGFIELD 88/1975 OCTOBER 12, 2026
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...25
DISCUSSION...25
AVIATION...GEELHART
CLIMATE...GEELHART
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