862
FXUS63 KILX 011722
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1222 PM CDT SAT AUG 1 2026
KEY MESSAGES
- WPC HAS A SLIGHT RISK EXCESSIVE RAINFALL OUTLOOK TODAY FOR
AREAS EAST OF I-55 AND NORTH OF I-70. FLASH FLOODING COULD
OCCUR WHERE GROUNDS ARE ALREADY SATURATED OR AFTER MULTIPLE
ROUNDS OF HEAVY RAIN OVER THE SAME LOCATIONS. EXPECT RAINFALL
TOTALS OF 1.5 TO 3.0 INCHES IN THESE PERSISTENT BANDS, WITH
SIGNIFICANTLY LOWER AMOUNTS ELSEWHERE.
- OUTSIDE OF THUNDERSTORMS, WINDS WILL BE QUITE GUSTY FROM THE
TIGHTENING PRESSURE GRADIENT TODAY. THE HREF SHOWS A 60-80%
CHANCE OF WIND GUSTS GREATER THAN 35 MPH WEST OF I-55 DURING
THE AFTERNOON AND EVENING HOURS.
- PLEASANT, DRY, AND WARM WEATHER FOLLOWS FOR MONDAY AND
TUESDAY, BEFORE RAIN CHANCES RETURN MID-TO-LATE NEXT WEEK.
CONFIDENCE IN THE LATE-WEEK TIMING REMAINS LOW, SO PLEASE
CHECK BACK FOR LATER FORECASTS.
UPDATE
ISSUED AT 920 AM CDT SAT AUG 1 2026
VERTICALLY STACKED LOW PRESSURE SYSTEM WAS CENTERED OVER WEST-
CENTRAL IL THIS MORNING. REGIONAL RADAR MOSAIC INDICATED
SCATTERED SHOWERS PINWHEELING AROUND THE LOW, WITH THE HIGHEST
COVERAGE OVER CENTRAL AND NORTHERN IL. THERMODYNAMIC PROFILES
REFLECT WEAK MID-LEVEL LAPSE RATES BUT SUBSTANTIAL LOW- LEVEL
MOISTURE. PRECIPITABLE WATER (PWAT) VALUES NEAR 1.6 INCHES WILL
NOURISH SLOW- MOVING CONVECTIVE SHOWERS AND A FEW ISOLATED
THUNDERSTORMS TODAY. THE HIGHEST CONVECTIVE INTENSITY FOCUSES
OVER EAST- CENTRAL ILLINOIS, WHERE HRRR AND HREF GUIDANCE
INDICATES HOURLY RAINFALL RATES UP TO 2-3 INCHES. GIVEN THESE
RAIN RATES, PONDING ON ROADWAYS AND LOCALIZED FLASH FLOODING IN
LOW- LYING OR URBAN AREAS REMAIN A RISK THROUGH EARLY THIS
EVENING. NAM/RAP SURFACE VORTICITY AND NON- SUPERCELL TORNADO
(NST) PARAMETER FIELDS DEPICT VALUES BETWEEN 1 AND 2 COINCIDENT
WITH THE CORE OF THE LOW PRESSURE SYSTEM, PARTICULARLY NEAR AND
SOUTH OF I-72 THIS AFTERNOON. SURFACE BASED INSTABILITY WILL
DEPEND HEAVILY ON SOLAR INSOLATION; IF CLOUD BREAKS DEVELOP THIS
AFTERNOON, LOCALIZED STRETCHING WILL ELEVATE THE RISK FOR
SHEAR-ZONE FUNNEL CLOUDS.
DISCUSSION
ISSUED AT 201 AM CDT SAT AUG 1 2026
A LOW PRESSURE SYSTEM IS SLOWLY TRAVELING THROUGH THE CENTRAL
PART OF THE UNITED STATES. SHOWERS AND THUNDERSTORMS WILL PUSH
THROUGH CENTRAL AND SOUTHEASTERN IL AGAIN TODAY, BUT WON'T BE A
COMPLETE WASHOUT AS THERE WILL BE BREAKS IN THE RAINFALL. THE
NEXT ROUND OF SHOWERS AND STORMS WILL DEVELOP LATER THIS MORNING
AS THE LOW PIVOTS INTO THE AREA. COVERAGE WILL BE SCATTERED.
OUTSIDE OF ANY STORMS, SKIES WILL BE CLOUDY. THE GREATEST
RAINFALL AMOUNTS WON'T BE WIDESPREAD AND WILL BE FAIRLY
LOCALIZED. AS OF THIS MORNING, MRMS IS ESTIMATING SOME LOCALIZED
POCKETS OF 1-2 INCHES ACROSS CENTRAL AND SOUTHEASTERN IL IN THE
LAST 24 HOURS. IN CONTRAST, SOME LOCATIONS HAVE SEEN LESS THAN
A QUARTER INCH IN THAT SAME TIME PERIOD. WPC HAS US IN A SLIGHT
RISK ERO FOR TODAY FOR AREAS EAST OF I-55 AND NORTH OF I-70.
FLASH FLOODING COULD OCCUR WHERE GROUNDS ARE ALREADY SATURATED
OR AFTER MULTIPLE ROUNDS OF HEAVY RAIN OVER THE SAME LOCATIONS.
AS THE LOW PRESSURE CENTER MOVES DIRECTLY OVERHEAD THROUGHOUT THE
DAY, THE NON-SUPERCELL TORNADO PARAMETER WILL INCREASE AS LOCALIZED
MAXIMUMS OF LOW-LEVEL SRH PIVOT OVER THE CENTRAL PART OF THE STATE.
SOMEONE MAY SEE A FUNNEL CLOUD (OR MULTIPLE) ACROSS CENTRAL IL.
OUTSIDE OF THUNDERSTORMS, WINDS WILL BE QUITE GUSTY FROM THE
TIGHTENING PRESSURE GRADIENT. THE HREF SHOWS A 60-80% CHANCE OF WIND
GUSTS GREATER THAN 35 MPH WEST OF I-55 DURING THE AFTERNOON AND
EVENING HOURS.
TEMPERATURES WILL BE UNSEASONABLY COOL WITH HIGHS IN THE 70S TODAY.
TEMPERATURES GRADUALLY INCREASE SOLIDLY BACK INTO THE 80S BY MIDWEEK
NEXT WEEK. LOWS WILL BE IN THE 60S FOR THE NEXT WEEK BEFORE WARMING
INTO THE 70S BY FRIDAY NIGHT. WEATHER WILL DRY OUT FOR MONDAY AND
TUESDAY, BUT ADDITIONAL RAIN CHANCES MUDDLE THE NEW WEEK STARTING
WEDNESDAY. THERE ARE LOW (~20%) CHANCE FOR SHOWERS AND THUNDERSTORMS
OFF AND ON THROUGHOUT NEXT WEEK FROM THE TIMING UNCERTAINTY OF WHEN
AN UPPER LEVEL SHORTWAVE WILL PUSH INTO ILLINOIS, DRAGGING A COLD
FRONT ALONG WITH IT.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1222 PM CDT SAT AUG 1 2026
LOW PRESSURE WAS CENTERED NEAR KDEC AT 17Z. NORTH OF THE LOW,
WIDESPREAD SHOWERS AND IFR CEILINGS WERE PREVALENT AT KPIA-KBMI.
SOUTH/EAST OF THE LOW, SPOTTY SHOWERS AND SCT-BKN IFR STRATUS
WAS PREVALENT AT THE OTHER CENTRAL IL TERMINALS. AS THE LOW
TRACKS EAST THIS AFTERNOON, IFR CONDITIONS ARE EXPECTED TO
EXPAND OVER THE REMAINDER OF THE TERMINALS. SHRA WILL DIMINISH
FROM THE WEST LATE AFTERNOON TO EARLY EVENING, COINCIDENT WITH A
TIGHTENING PRESSURE GRADIENT ON THE BACK SIDE OF THE LOW. THIS
WILL RESULT IN N/NE GUSTS INCREASING TO 20-25 KT. THE GUSTS MAY
SUBSIDE FOR A TIME LATER TONIGHT, THEN RETURN AFTER SUNRISE. IFR
CEILINGS WILL BE PREVALENT INTO SUNDAY MORNING, WITH HIGHER
PROBABILITIES OF MVFR CEILINGS WEST OF I-55 BY LATE MORNING.
ILX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH LATE TONIGHT FOR ILZ045-046-055-057.
KEY MESSAGES...COPPLE
UPDATE...25
DISCUSSION...COPPLE
AVIATION...25
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