403
FXUS63 KILX 070844
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
ISSUED BY NATIONAL WEATHER SERVICE PADUCAH KY
344 AM CDT TUE JUL 7 2026
KEY MESSAGES
- PLEASANT WEATHER THROUGH WEDNESDAY: DRY AND PLEASANT
CONDITIONS DOMINATE EARLY THIS WEEK WITH HIGHS IN THE MID-TO-
UPPER 80S. ONLY AN ISOLATED AFTERNOON STORM IS POSSIBLE
(20-30% CHANCE), MAINLY SOUTH OF INTERSTATE 72.
- FLASH FLOODING RISK THURSDAY AND FRIDAY: A STALLED FRONT
BRINGS A HIGH CHANCE (60-70%) FOR WIDESPREAD SHOWERS AND
STORMS. TORRENTIAL RAINFALL FROM REPEATING STORMS INTRODUCES A
RISK OF LOCALIZED FLASH FLOODING AND ISOLATED DAMAGING WINDS.
- UNCERTAIN HEAT POTENTIAL NEXT WEEK: HIGH UNCERTAINTY EXISTS
FOR MID-JULY. CENTRAL ILLINOIS WILL EITHER EXPERIENCE PERIODIC
THUNDERSTORM COMPLEXES OR A PERIOD OF DANGEROUS, EXCESSIVE
HEAT, DEPENDING ON HOW FAR EAST A BUILDING WEATHER RIDGE
TRACKS.
DISCUSSION
ISSUED AT 335 AM CDT TUE JUL 7 2026
TODAY THROUGH WEDNESDAY (SHORT-TERM QUIETER PERIOD)...
A BENIGN AND RELATIVELY COMFORTABLE WEATHER PATTERN HAS
ESTABLISHED ITSELF ACROSS CENTRAL ILLINOIS. THE REGION
CURRENTLY SITS IN A TRANSITION ZONE BETWEEN A COMPACT, CUT-OFF
UPPER-LEVEL LOW SPINNING OVER SOUTHEAST MISSOURI AND A BUILDING
MID-LEVEL RIDGE SHIFTING EASTWARD THROUGH THE CORN BELT.
ALTHOUGH THE PROXIMITY OF THE UPPER LOW WARRANTS LOW-END
AFTERNOON PULSE STORM CHANCES (20-30% POPS), THE EXPANDING
INFLUENCE OF THE ADVANCING RIDGE WILL LIKELY KEEP MOST OF THE
FORECAST AREA COMPLETELY DRY TODAY. EXPECT SEASONABLY PLEASANT
CONDITIONS FOR EARLY JULY, WITH AFTERNOON HIGHS TOPPING OUT IN
THE MID-80S. COMBINED WITH DEWPOINTS HOVERING IN THE UPPER 60S
TO AROUND 70F, MAXIMUM HEAT INDEX VALUES SHOULD REMAIN CAPPED IN
THE UPPER 80S. THIS STAGNANT, BLOCKY CONFIGURATION WILL REMAIN
LARGELY IN PLACE THROUGH WEDNESDAY AS THE UPPER LOW SLOWLY
MIGRATES EASTWARD INTO THE OHIO RIVER VALLEY. HIGH TEMPERATURES
WILL NUDGE UPWARD INTO THE UPPER 80S TO NEAR 90F AS 850 MB
TEMPERATURES WARM SLIGHTLY UNDER THE EASTWARD-SHIFTING RIDGE
AXIS. ISOLATED AFTERNOON THUNDERSTORMS (20-30% COVERAGE) REMAIN
POSSIBLE, PRIMARILY CONCENTRATED SOUTH OF THE INTERSTATE 72
CORRIDOR CLOSER TO THE DEPARTING LOW.
THURSDAY THROUGH FRIDAY NIGHT (UNSETTLED & HYDRO CONCERNS)...
THE SYNOPTIC PATTERN SHIFTS DECISIVELY ON THURSDAY AS POTENT
SHORTWAVE ENERGY DIVES INTO THE UPPER MIDWEST, BREAKING DOWN THE
RIDGE AND PUSHING A WEAK COLD FRONT INTO THE REGION BY THURSDAY
NIGHT. BECAUSE THE PRIMARY UPPER-LEVEL DYNAMICS WILL QUICKLY
OUTRUN THE SURFACE BOUNDARY, THE FRONT IS PROJECTED TO BECOME
INCREASINGLY PARALLEL TO THE MID-LEVEL FLOW. THIS WILL CAUSE THE
BOUNDARY TO SHEAR OUT AND STALL DIRECTLY ACROSS CENTRAL ILLINOIS
ON FRIDAY. THIS STALLED BOUNDARY WILL SERVE AS THE FOCAL POINT
FOR ACTIVE, UNSETTLED WEATHER DURING THE LATTER HALF OF THE
WEEK, YIELDING HIGH PROBABILITIES (60-70%) FOR WIDESPREAD
RAINFALL. THE ENVIRONMENT WILL TURN MODERATELY TO STRONGLY
UNSTABLE AHEAD OF THE FRONT, WITH MUCAPE VALUES CLIMBING INTO
THE 2000-3000 J/KG RANGE. DEEP- LAYER VERTICAL WIND SHEAR IS
PROGGED TO PEAK AROUND 30 KNOTS ON THURSDAY AFTERNOON BEFORE
WEAKENING INTO FRIDAY. WHILE THE IMPROVED SHEAR PROFILES ON
THURSDAY COULD SUPPORT A FEW ORGANIZED UPDRAFTS CAPABLE OF
ISOLATED SEVERE WEATHER, THE PRIMARY CONCERN IS SHIFTING HEAVILY
TOWARD LOCALIZED FLASH FLOODING DRIVEN BY HIGHLY EFFICIENT
WARM-RAIN PROCESSES. PRECIPITABLE WATER (PWAT) VALUES ARE
FORECAST TO SURGE ABOVE 2.0 INCHES, WHICH EXCEEDS THE 90TH
PERCENTILE FOR JULY CLIMATOLOGY. CONSEQUENTLY, TRAINING
CONVECTIVE CELLS PRODUCING TORRENTIAL RAINFALL RATES WILL BE THE
MAIN HAZARD TO MONITOR, ALONG WITH LOCALIZED WET DOWNBURSTS
CAPABLE OF ISOLATED DAMAGING WIND GUSTS.
SATURDAY THROUGH NEXT WEEK (EXTENDED HEAT & MCS POTENTIAL)...
ONCE THE STALLED FRONT FINALLY DISSIPATES LATE IN THE WEEK, LONG-
RANGE GUIDANCE EXHIBITS EXCELLENT AGREEMENT REGARDING THE EXPANSION
OF A HIGH-AMPLITUDE SUBTROPICAL RIDGE OVER THE CENTRAL UNITED STATES.
MEDIUM-RANGE ENSEMBLES (GEFS/EPS/GEPS) CONSISTENTLY PROJECT AN
ANOMALOUS UPPER-LEVEL HIGH CENTERING NEAR THE ROCKIES DURING THE
JULY 14-17 TIMEFRAME. SENSIBLE WEATHER ACROSS CENTRAL ILLINOIS
DURING THE EXTENDED PERIOD WILL DEPEND HEAVILY ON THE EXACT
LONGITUDINAL POSITION OF THIS RIDGE CORE. A MORE WESTERN RIDGE
ORIENTATION WOULD PLACE THE LOCAL AREA UNDER ACTIVE NORTHWEST
FLOW ALOFT. THIS WOULD OPEN THE DOOR FOR PERIODIC, RIDGE-RIDING
MESOSCALE CONVECTIVE SYSTEMS (MCSS) THAT WOULD TEMPER AFTERNOON
TEMPERATURES VIA PERSISTENT CLOUD COVER AND CONVECTIVE DEBRIS.
CONVERSELY, IF THE RIDGE CORE MIGRATES FURTHER EASTWARD DIRECTLY
INTO THE CORN BELT, A SPELL OF DANGEROUS, EXCESSIVE HEAT COULD
RAPIDLY DEVELOP BY MID-JULY. GIVEN THE TYPICAL MODEL VARIANCE AT
THIS TIME RANGE, TRENDS WILL BE MONITORED CLOSELY OVER THE
COMING FORECAST CYCLES.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1150 PM CDT MON JUL 6 2026
HIGH PRESSURE WILL REMAIN OVER THE MIDWEST OVERNIGHT INTO
TUESDAY WITH A LIGHT NORTHEAST WIND UNDER 10 KT THROUGH THE
PERIOD ACROSS CENTRAL ILLINOIS. SOME PATCHY FOG IS POSSIBLE
OVERNIGHT INTO TUESDAY MORNING, ESPECIALLY AT THE EASTERN MOST
TERMINALS (BMI/DEC/CMI).
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...MJA
DISCUSSION...MJA
AVIATION...DEUBELBEISS
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