333
FXUS63 KILX 200159
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
859 PM CDT TUE MAY 19 2026
KEY MESSAGES
- DRIER AND COOLER WEATHER RETURNS BRIEFLY FOR MIDWEEK. THE
PATTERN TURNS UNSETTLED ONCE AGAIN LATE THIS WEEK INTO THE
WEEKEND WITH SEVERAL OPPORTUNITIES FOR SHOWERS AND SCATTERED
STORMS.
UPDATE
ISSUED AT 859 PM CDT TUE MAY 19 2026
UPDATED THE FORECAST TO SIGNIFICANTLY REDUCE POPS THIS EVENING
AND LIMIT NORTHWARD EXPANSION OF POPS OVERNIGHT. 0130Z/830PM
REGIONAL RADAR MOSAIC SHOWS PRE-FRONTAL CONVECTION E/SE OF THE
KILX CWA FROM SOUTHERN INDIANA SOUTHWESTWARD TO THE OZARKS.
WHILE AN ISOLATED SHOWER/STORM CANNOT BE RULED OUT SOUTH OF
I-70, IT APPEARS CLOUDY AND DRY CONDITIONS WILL PREVAIL ACROSS
THE BOARD THROUGH MIDNIGHT. AS A SHORT-WAVE TROUGH OVER THE
LOWER MISSISSIPPI RIVER VALLEY PIVOTS NORTHEASTWARD AND
INTERACTS WITH THE SLOWLY DEPARTING BOUNDARY, SHOWERS WILL
DEVELOP ACROSS SOUTHERN ILLINOIS AND SPREAD NORTHWARD LATE
TONIGHT INTO WEDNESDAY MORNING. HRRR/RRFS INDICATE THE BULK OF
THE SHOWERS FOCUSING ALONG/SOUTH OF I-70 AND THINK THIS SEEMS
REASONABLE GIVEN THE INFLUX OF DRIER BOUNDARY LAYER AIR FROM
THE NORTH. HAVE THEREFORE OPTED TO KEEP RAIN CHANCES CONFINED TO
THE SE CWA LATE TONIGHT...EVENTUALLY REACHING AS FAR NORTH AS A
DANVILLE TO SHELBYVILLE LINE WEDNESDAY MORNING BEFORE SHIFTING
INTO INDIANA DURING THE AFTERNOON.
DISCUSSION
ISSUED AT 109 PM CDT TUE MAY 19 2026
MIDDAY SURFACE ANALYSIS SHOWS A ~1004 MB LOW NORTH OF THE GREAT
LAKES REGION IN SOUTHEAST ONTARIO WITH A TRAILING COLD FRONT
STRETCHED FROM NORTHERN MICHIGAN THROUGH THE MIDDLE MISSISSIPPI
VALLEY. AHEAD OF THE FRONT, A FEW REMNANT OUTFLOW BOUNDARIES FROM
OVERNIGHT CONVECTION ARE NOTED WITH THE MOST PREDOMINANT ONE
STRETCHED FROM ROUGHLY ROBINSON TO LAWRENCEVILLE AS OF 1 PM. THIS
BOUNDARY IS MOVING STEADILY TO THE EAST AND WILL LIKELY BE THE MAIN
FOCUS FOR SCATTERED THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON
INTO EVENING. DEWPOINTS IN THE UPPER 60S TO LOW 70S OUT AHEAD OF THE
FRONT/OUTFLOW BOUNDARY HAVE ALLOWED SBCAPE TO BECOME MODERATELY
STRONG. MORE FAVORABLE DEEP LAYER SHEAR WILL BE DISPLACED CLOSER TO
THE COLD FRONT, THOUGH HIGH PWATS AND STEEP LOW-LEVEL LAPSE RATES
MAY BE ENOUGH TO SUPPORT A FEW DAMAGING WIND GUSTS. THE 12Z CAMS
HAVE SHOWN A SHIFT EASTWARD WITH STORM ACTIVITY, WITH THE FOCUS
BEING SOUTHEAST OF A TERRE HAUTE TO FLORA LINE THROUGH EARLY
EVENING. THE 19.12Z HREF 24 HOUR LPMM SHOWS LOCALIZED POCKETS OF 1-
2"+ OF RAIN OCCURING WITH STORMS, WHICH LOOKS TO BE SOUTH AND EAST
OF THE HARDEST HIT RAIN AREAS FROM YESTERDAY.
THE COLD FRONT WILL WORK THROUGH THE AREA THIS EVENING, REACHING THE
OHIO VALLEY AROUND MIDNIGHT. MUCH OF THE PRECIPITATION SHOULD COME
TO AN END AS THE FRONT MOVES THROUGH LATER THIS EVENING. HOWEVER, A
SHORTWAVE TROUGH LIFTING FROM THE SOUTHERN PLAINS INTO THE TENNESSEE
VALLEY WILL NUDGE THE FRONT BACK NORTHWARD OVERNIGHT AND SPREAD
LIGHT SHOWER AND ISOLATED THUNDER CHANCES BACK INTO SOUTHEAST PARTS
OF THE STATE THROUGH WEDNESDAY MORNING. HIGH PRESSURE RIDGING WILL
INCREASE LARGE-SCALE SUBSIDENCE AND ULTIMATELY PUSH THE FRONT BACK
SOUTH OF HERE, PUTTING AN END TO THE PRECIPITATION BY WEDNESDAY
AFTERNOON.
HIGH PRESSURE WILL SHIELD US BRIEFLY FROM PRECIPITATION, WITH COOLER
AND DRIER CONDITIONS EXPECTED THROUGH MUCH OF THURSDAY. A WESTERN
TROUGH WILL WORK INTO THE CENTRAL US AND SPAWN SEVERAL SHORTWAVES
INTO THE MIDWEST STATES LATE THIS WEEK THROUGH THE WEEKEND, BRINGING
THE RETURN OF SCATTERED PRECIPITATION CHANCES. TEMPERATURES AND
MOISTURE WILL STEADILY INCREASE THROUGH THE WEEKEND AND MAY SUPPORT
THE DEVELOPMENT OF THUNDERSTORMS AT TIMES. HOWEVER, OVERALL WEAK
FORCING SHOULD LARGELY MITIGATE ANY CHANCES FOR SEVERE WEATHER
THROUGH EARLY NEXT WEEK. MACHINE LEARNING PROBABILITIES SUPPORT THIS
BY KEEPING ANY CHANCES FOR SEVERE WEATHER SOUTH OF HERE.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 656 PM CDT TUE MAY 19 2026
MVFR CEILINGS HAVE SPREAD ACROSS THE CENTRAL ILLINOIS TERMINALS
EARLY THIS EVENING IN THE WAKE OF A DEPARTING COLD FRONT.
HRRR/RAP FORECASTS SUGGEST THE CEILINGS WILL GRADUALLY RISE TO
LOW VFR BY MID TO LATE EVENING: HOWEVER, A WAVE OF LOW PRESSURE
RIDING ALONG THE FRONTAL BOUNDARY WILL SPREAD LOW CLOUDS AND
PERHAPS A FEW LIGHT SHOWERS AS FAR NORTH AS THE I-72 CORRIDOR
OVERNIGHT INTO EARLY WEDNESDAY MORNING. HAVE THEREFORE
RE-INTRODUCED MVFR AT KDEC/KCMI BETWEEN 08Z/09Z AND 17Z/18Z.
AFTER THAT, CEILINGS WILL GRADUALLY SCATTER FROM WEST TO EAST
DURING THE AFTERNOON. WINDS WILL INITIALLY BE NW AT 10-15KT, BUT
WILL VEER TO N TOWARD MIDNIGHT, THEN TO NE DURING THE DAY
WEDNESDAY.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...
UPDATE...BARNES
DISCUSSION...NMA
AVIATION...BARNES
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