992
FXUS63 KILX 241815
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
115 PM CDT THU SEP 24 2026
KEY MESSAGES
- MOSTLY CLOUDY AND COOL WEATHER WILL PREVAIL THE NEXT SEVERAL
DAYS BEFORE A PATTERN CHANGE BRINGS UNSETTLED CONDITIONS,
INCLUDING THE POTENTIAL FOR THUNDERSTORMS, BY THE MIDDLE OF
NEXT WEEK.
DISCUSSION
ISSUED AT 115 PM CDT THU SEP 24 2026
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS AN EXPANSIVE AREA OF
HIGH PRESSURE CENTERED OVER QUEBEC, STRETCHING WEST THROUGH THE
MIDDLE MISSISSIPPI VALLEY. THE SURFACE HIGH WILL REMAIN STEADILY
ANCHORED IN PLACE THROUGH THE WEEKEND AS A DEVELOPING
NOR'EASTER IMPACTS THE MID-ATLANTIC AND NORTHEAST US. HERE
LOCALLY, EAST- NORTHEAST WINDS HAVE KEPT A CONTINUOUS FEED OF
LOW STRATUS TRAPPED BENEATH A SUBSIDENCE INVERSION, HOLDING
TEMPERATURES SEVERAL DEGREES BELOW NORMAL. ASIDE FROM OCCASIONAL
BREAKS IN THE CLOUDS, MOSTLY CLOUDY CONDITIONS WILL CONTINUE
THE NEXT FEW DAYS WITH LITTLE CHANGE IN THE SURFACE FLOW.
BECAUSE OF THIS, TEMPERATURES WILL REMAIN COOLER THROUGH THE
WEEKEND WITH HIGHS PEAKING IN THE UPPER 60S TO MIDDLE 70S.
FURTHER WEST, AN UPPER TROUGH OVER THE SOUTHWEST US WILL LIFT
NORTHEAST, WEAKENING AS IT APPROACHES CENTRAL US RIDGING. AN
ASSOCIATED PLUME OF TROPICAL MOISTURE AHEAD OF THIS FEATURE
CURRENTLY EXTENDS ACROSS THE PLAINS STATES AND WILL GRADUALLY SHIFT
EAST THROUGH THE WEEKEND, ENTERING WEST-CENTRAL IL BY FRIDAY
MORNING. DESPITE THE LACK OF LARGE SCALE FORCING, OCCASIONAL
SHORTWAVES IN THE UPPER FLOW WILL PROMOTE ISOLATED TO SCATTERED
LIGHT RAIN SHOWERS WEST OF I-55 THROUGH EARLY SUNDAY. LITTLE TO NO
ACCUMULATION WILL RESULT FROM THESE.
BY EARLY NEXT WEEK, BROAD RIDGING WILL TAKE SHAPE OVER THE CENTRAL
US AS THE NOR'EASTER/SURFACE LOW EVENTUALLY MOVES INTO NEWFOUNDLAND.
A PACIFIC LOW WILL MOVE ONSHORE THE COAST OF CALIFORNIA SUNDAY
NIGHT/MONDAY AND WORK INTO THE CENTRAL US BY MIDWEEK. FORECAST
GUIDANCE DIFFERS ON THE STRENGTH AND TRACK OF THIS SYSTEM WITH THE
ECMWF FAVORING A SLOWER CLOSED WAVE VS. THE GFS'S FASTER OPEN
WAVE. DESPITE THE DIFFERENCES, A WETTER AND MORE ACTIVE WEATHER
PATTERN IS FAVORED BY THE MIDDLE TO LATE PARTS OF NEXT WEEK.
ALTHOUGH THE SEVERE WEATHER THREAT APPEARS LOW AT THIS TIME, THE
POTENTIAL FOR HEAVY RAIN DOES EXIST.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1210 PM CDT THU SEP 24 2026
LOW MVFR STRATUS SHOULD LIFT TO VFR LATER THIS AFTERNOON AND
REMAIN ABOVE 3K FT THROUGH THE OVERNIGHT HOURS. ISOLATED TO
SCATTERED SHOWERS SPILL INTO WEST-CENTRAL ILLINOIS FRIDAY
MORNING, BRINGING ANOTHER PERIOD OF MVFR CEILINGS TO KPIA AND
POSSIBLY KSPI AFTER 12Z. WINDS WILL REMAIN STEADY OUT OF THE THE
EAST-NORTHEAST THROUGH THE PERIOD WITH SPEEDS BELOW 12 KTS.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...NMA
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