776
FXUS63 KILX 220537
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1237 AM CDT WED JUL 22 2026
KEY MESSAGES
- PLEASANT MID-WEEK WEATHER: EXPECT CALM WEATHER WITH BELOW-
NORMAL TEMPERATURES WEDNESDAY AND THURSDAY, WITH AFTERNOON
HIGHS REMAINING IN THE MID-TO-UPPER 70S.
- HEAT RETURNS THIS WEEKEND: HIGH TEMPERATURES REBOUND INTO THE 90S
BY SUNDAY AND MONDAY. THERE IS A 20% CHANCE OF PERIODIC
THUNDERSTORMS RETURNING LATE FRIDAY INTO EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 1219 PM CDT TUE JUL 21 2026
NEAR TERM FORECAST...
THE CURRENT SURFACE ANALYSIS PLACES A COLD FRONT ALONG THE I-70
CORRIDOR, WITH EXPECTED PROGRESSION SOUTHEASTWARD AND OUT OF
OUR CWA BY MID-AFTERNOON. RAP ANALYSIS CONTINUES TO HIGHLIGHT AN
UNSTABLE AIRMASS AHEAD OF THE BOUNDARY, CHARACTERIZED BY MLCAPE
VALUES NEAR 3000 J/KG AND DEEP-LAYER SHEAR PROFILES OF 30-40
KT. GIVEN THIS OVERLAP, A BRIEF WINDOW OF OPPORTUNITY FOR SEVERE
THUNDERSTORM DEVELOPMENT EXISTS THROUGH MID AFTERNOON BEFORE
THE FRONT EXITS THE REGION. BEHIND THE BOUNDARY, A COOLER AND
DRIER AIR MASS IS FILTERING INTO THE REGION ON GUSTY NORTHWEST
WINDS. DEW POINTS HAVE ALREADY BEGUN A DOWNWARD TREND,
EVENTUALLY BOTTOMING OUT IN THE 50S ACROSS THE NORTHERN TIER OF
THE FORECAST AREA TONIGHT, WITH AMBIENT TEMPERATURES SETTLING
INTO THE 60S UNDER MOSTLY CLEAR SKIES.
WEDNESDAY THROUGH FRIDAY...
THE MIDDLE OF THE WEEK WILL FEATURE A TRANSITION TO A MORE
TRANQUIL REGIME AS A ROBUST CANADIAN HIGH-PRESSURE SYSTEM
BUILDS SOUTHEAST ACROSS THE MIDWEST. THIS WILL FACILITATE A
TREND TOWARD BELOW-NORMAL TEMPERATURES, WITH AFTERNOON HIGHS
CONFINED TO THE MID TO UPPER 70S. DRY CONDITIONS ARE ANTICIPATED
TO PREVAIL THROUGH THURSDAY NIGHT. BY FRIDAY, GUIDANCE SUGGESTS
THE POTENTIAL FOR WARM AIR ADVECTION-DRIVEN CONVECTION
ORIGINATING TO OUR WEST. WHILE CONFIDENCE REMAINS LOW, THERE IS
A NON-ZERO POTENTIAL FOR THESE SHOWERS AND THUNDERSTORMS TO
ENCROACH UPON PORTIONS OF CENTRAL ILLINOIS; HOWEVER, THE LACK OF
SIGNIFICANT MOISTURE RETURN CURRENTLY LIMITS MORE ROBUST POP
INCLUSION.
THIS WEEKEND INTO NEXT WEEK...
AS THE SURFACE RIDGE TRANSLATES TOWARD THE ATLANTIC COAST OVER
THE WEEKEND, THE RETURN OF LOW-LEVEL SOUTHERLY FLOW WILL
INITIATE A NOTICEABLE WARMING TREND. TEMPERATURES ARE PROGGED TO
REBOUND SIGNIFICANTLY, WITH WIDESPREAD 90S RETURNING TO THE
FORECAST BY SUNDAY AND MONDAY. THE SYNOPTIC PATTERN REMAINS
ANCHORED BY NORTHWEST FLOW ALOFT, WITH PERIODIC, LOWER-AMPLITUDE
SHORTWAVES EXPECTED TO TRAVERSE THE REGION. THESE DISTURBANCES
MAY SERVE AS CATALYSTS FOR CONVECTIVE INITIATION, THOUGH TIMING
AND PLACEMENT REMAIN DIFFICULT TO RESOLVE THIS FAR OUT. HAVE
CAPPED PRECIPITATION CHANCES AT APPROXIMATELY 20% DURING THIS
TIMEFRAME UNTIL BETTER AGREEMENT IS REACHED AMONG SHORT-RANGE
GUIDANCE.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1237 AM CDT WED JUL 22 2026
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. LOWER
CLOUDS ARE ADVECTING OFF LAKE MICHIGAN AND MOVING SOUTHWEST
TOWARD THE TAF SITES. CLOUD LEVEL LOOKS TO BE AROUND 4KFT FOR
NOW AND WILL HAVE SCATTERED CLOUDS OVERNIGHT AT THE TAF SITES.
EXPECTING ADDITIONAL DIURNAL CU TO DEVELOP DURING THE DAY WITH
SOME CIRRUS, BUT THEN THE CU WILL DISSIPATE IN THE EARLY EVENING
HOURS WITH JUST SOME HIGH CIRRUS LEFT OVER IN THE NIGHT. WINDS
WILL BE OUT OF THE NORTHWEST TO NORTH TO START BUT THEN BECOME
NORTHEASTERLY THE REMAINDER OF THE FORECAST PERIOD. WIND SPEEDS
WILL BE AROUND 10KTS AT BMI, BUT THE OTHER SITES WILL SEE
LIGHTER WINDS AND VARIABLE. WINDS INCREASE IN SPEED DURING THE
DAY BUT THEN LIGHTEN AGAIN IN THE EVENING
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...DEUBELBEISS
DISCUSSION...DEUBELBEISS
AVIATION...AUTEN
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