444
FXUS63 KILX 041815
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
115 PM CDT TUE AUG 4 2026
KEY MESSAGES
- THERE IS A LOW RISK FOR SEVERE STORMS WEDNESDAY EVENING, WITH
DAMAGING WINDS AS THE MAIN THREAT. SPC HAS A MARGINAL RISK
(LEVEL 1 OF 5) FOR SEVERE WEATHER WEST AND NORTHWEST OF A ST
LOUIS TO WATSEKA LINE WEDNESDAY.
- HOT AND HUMID WEATHER RETURNS EARLY NEXT WEEK WITH HEAT INDEX
VALUES APPROACHING 100 DEGREES, THOUGH PASSING STORM COMPLEXES
COULD OCCASIONALLY TEMPER THE HEAT.
DISCUSSION
ISSUED AT 235 AM CDT TUE AUG 4 2026
DRY WEATHER IS EXPECTED THROUGH TONIGHT AS A HIGH PRESSURE LINGERS
OVER THE REGION. HIGHS IN THE 80S AND LOW IN THE 60S WILL BE IN
PLACE FOR THE WEEK. TEMPERATURES LOOK TO NEAR OR RISE ABOVE 90
DEGREES FOR HIGHS BY SUNDAY INTO THE NEW WEEK, WITH INCREASING
HUMIDITY. THE LREF SHOWS A 50-80% CHANCE OF APPARENT TEMPERATURES
BEING GREATER THAN 95 DEGREES ON MONDAY AFTERNOON AND 50-70% CHANCE
ON TUESDAY AFTERNOON ACROSS THE ENTIRE FORECAST AREA. THE CPC HAS
BOTH THE 6-10 AND 8-14 DAY OUTLOOKS WITH 60-80% CHANCE OF ABOVE
NORMAL TEMPERATURES, SO THE SWELTERING WEATHER ISN'T OVER QUITE YET
FOR THIS SUMMER. THIS IS SAID WITH THE CAVEAT OF IF WE GET SOME
WIDESPREAD THUNDERSTORM ACTIVITY NEXT WEEK, THE HEAT INDICES
MAY NOT BE ABLE TO ACHIEVE 95-100+ DEGREES.
A MORE ACTIVE PATTERN WILL RETURN LATE TONIGHT AS A COLD FRONT
PUSHES INTO THE STATE BY TOMORROW. THERE IS SOME DISCREPANCIES IN
THE CAMS WITH THE TIMING OF THE EARLIER ROUND OF SHOWERS AND
THUNDERSTORMS. THE HRRR HAS THE ACTIVITY ENTERING THE WESTERN CWA BY
10Z, WHEREAS THE NAMNEST HAS IT ENTERING BY 15Z. IT LOOKS TO BE THAT
THERE WILL BE MULTIPLE ROUNDS OF SHOWERS AND STORMS FROM WEDNESDAY
MORNING TO THURSDAY AFTERNOON. MUCAPE VALUES (AND SIMILARLY SBCAPE
VALUES) ARE STILL LOOKING TO BE AROUND 1500-2500 J/KG AND BULK SHEAR
VALUES OF 30-40 KNOTS. SRH VALUES LOOK TO BE AROUND 200-300 IN THE
VICINITY OF THE ACTIVITY. THE SPC HAS A MARGINAL RISK (LEVEL 1 OF 5)
IN PLACE FOR WEDNESDAY WEST AND NORTHWEST OF A ST LOUIS TO WATSEKA
LINE. IF ANY SEVERE WEATHER OCCURS, IT LOOKS LIKE CONDITIONS ARE
BEST FROM MID AFTERNOON INTO THE EARLY EVENING WEDNESDAY. ALL
HAZARDS ARE IN PLAY, WITH THE MAIN CONCERN BEING DAMAGING WIND
GUSTS. OVERNIGHT, THE SEVERE THREAT SHOULD WANE WITHOUT THE DAYTIME
HEATING EFFECT. WPC DOES HAVE A SLIGHT RISK ERO IN PLACE FOR NEARLY
THE SAME AREA AS THE SPC OUTLOOK. THE CAMS ARE HINTING AT SOME
TRAINING OVER THE SAME AREAS ON WEDNESDAY INTO THURSDAY. WE WILL
NEED TO MONITOR FOR A FLASH FLOODING THREAT.
THE FRONT IS APPEARING MORE LIKELY TO LINGER OVER THE AREA BEYOND
WEDNESDAY, KEEPING US IN A MORE ACTIVE PATTERN THROUGH LATE WEEK.
THURSDAY HAS A VERY SIMILAR ENVIRONMENTAL LOOK IN PLACE, ESPECIALLY
OVER WEST/SOUTHWESTERN IL, IN THE AFTERNOON. EACH DAY, FROM THURSDAY
TO MONDAY, COULD SEE SOME LOW RISKS FOR SEVERE WEATHER BASED OFF A
COARSE LOOK AT THERMODYNAMICS IN PLACE AND A LOOK AT THE MACHINE
LEARNING MODELS. WE WILL CONTINUE TO MONITOR THE SHOWERY AND SEVERE
THUNDERSTORM POSSIBILITIES BEYOND THURSDAY MORNING AS WE MOVE
FORWARD IN THE WEEK.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1259 PM CDT TUE AUG 4 2026
AFTERNOON CUMULUS WILL DISSIPATE THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. THEN, CLEAR SKIES WILL GIVE WAY TO INCREASING
AND LOWERING CLOUDS INTO WEDNESDAY MORNING AS A COLD FRONT AND
ITS PREFRONTAL PRECIPITATION PUSH INTO WEST CENTRAL ILLINOIS.
WHILE VFR CONDITIONS ARE FORECAST TO PERSIST THROUGHOUT THIS TAF
CYCLE, WE WILL NEED TO MONITOR TRENDS CENTERED AROUND THE 12Z
PERIOD, AS SOME MODEL GUIDANCE DEPICTS A BROKEN LINE OF SHOWERS
AND THUNDERSTORMS CROSSING INTO THE ILLINOIS RIVER BEFORE
DETERIORATING. FOR THIS REASON, WE HAVE ADDED A PROB30 GROUP FOR
-TSRA AT KPIA BETWEEN 12Z-15Z.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...COPPLE
DISCUSSION...COPPLE
AVIATION...MJA
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