436
FXUS63 KILX 150738
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
238 AM CDT FRI MAY 15 2026
KEY MESSAGES
- PERIODIC STRONG TO SEVERE STORM CHANCES WILL PERSIST THROUGH
EARLY NEXT WEEK...WITH THE GREATEST PROBABILITY FOR CONVECTION
FOCUSING ON SATURDAY...THEN AGAIN LATE MONDAY INTO TUESDAY.
- AFTER A COUPLE MORE MILD DAYS, A PREVIEW OF SUMMER WILL ARRIVE
BY EARLY NEXT WEEK AS HIGHS SOAR INTO THE 80S BY SATURDAY INTO
TUESDAY.
DISCUSSION
ISSUED AT 238 AM CDT FRI MAY 15 2026
AN ACTIVE PERIOD OF WEATHER IS IN PLACE THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. TONIGHT, A SHORTWAVE WILL PASS OVERHEAD, BRINGING A
MCS INTO IL. AS OF NOW (2AM), STORMS HAVE BEGUN TO MULTIPLY AND GROW
ALONG AND WEST OF THE MISSISSIPPI RIVER THEN WILL CONTINUE TO MOVE
EAST THROUGH IL. THE SYSTEM AS A WHOLE WILL BE MOVING INTO A LESS
SUPPORTIVE ENVIRONMENT, SO IT IS EXPECTED TO BE ELEVATED AND SUB
SEVERE. RAINFALL AMOUNTS ARE FORECAST TO BE GENERALLY LESS THAN HALF
AN INCH THROUGH 18Z.
THIS EVENING INTO TONIGHT MAY HAVE ADDITIONAL SHOWERS AND
THUNDERSTORMS, OF WHICH COULD BE STRONG TO SEVERE. MOST OF THE DAY
AFTER NOON SHOULD BE PRETTY DRY FOR MUCH OF CENTRAL AND SOUTHEASTERN
IL. HEFTY CAPPING (500-800 CIN) WILL BE IN PLACE DURING THIS TIME,
WHICH MAY STUNT THE DEVELOPMENT OF ANY STORMS. BULK SHEAR OF 30-40
KNOTS. MUCAPE VALUES OF 1000-2000 J/KG. SPC HAS A MARGINAL RISK
(LEVEL 1 OF 5) FOR DAMAGING WINDS AND LARGE HAIL DURING THIS TIME
FOR WEST OF I-57. THE CAMS SHOW THE SYSTEM MOVING IN FROM IOWA TO BE
DECAYING AS IT APPROACHES THE FORECAST AREA AROUND MIDNIGHT.
SATURDAY, ANOTHER MARGINAL RISK FOR SEVERE WEATHER IS IN PLACE FOR
ALL OF CENTRAL IL AND MOST OF SOUTHEASTERN IL. SUFFICIENT DEEP-
LAYER SHEAR AND 1000-2000 J/KG OF MUCAPE AS ANOTHER WEAK SHORTWAVE
PASSES OVERHEAD SHOULD SUPPORT AN ISOLATED SEVERE THREAT WITH
DAMAGING WIND GUSTS. THE STORMS MAY STRUGGLE TO DEVELOP SINCE THE
LIFT SOURCE WON'T BE VERY STRONG. HOWEVER, ANY THAT DO DEVELOP HAVE
A VERY SUPPORTIVE ENVIRONMENT TO BECOME SEVERE.
BEYOND SATURDAY, THERE LOOKS TO BE THE POTENTIAL FOR MORE WAVES OF
SEVERE WEATHER INTO THE NEW WEEK, INCLUDING KNOX, FULTON, AND STARK
COUNTIES HAVING A MARGINAL RISK SUNDAY. THERE IS A 15% CHANCE (EQUAL
TO A SLIGHT RISK) FOR SEVERE WEATHER FROM SPC FOR MONDAY ALONG AND
WEST OF I-55 AND TUESDAY FOR MOST OF THE FORECAST AREA. WE WILL
CONTINUE TO MONITOR BUT WILL NEED TO MAKE IT THROUGH THE NEXT 3 DAYS
OF SEVERE WEATHER BEFORE PINNING ANYTHING DOWN FOR SUNDAY-TUESDAY.
TODAY IS THE COOLEST DAY FOR A FEW DAYS WITH HIGHS ONLY IN THE MID
TO UPPER 70S. OTHERWISE, TEMPERATURES ARE GOING TO BE WARM THROUGH
EARLY NEXT WEEK WITH HIGHS IN THE 80S AND LOWS IN THE 60S, NEAR
70.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1227 AM CDT FRI MAY 15 2026
VFR CONDITIONS ARE ANTICIPATED TO BE THE PRIMARY FLIGHT CATEGORY
ACROSS THE CENTRAL ILLINOIS TERMINALS, EXCLUDING TEMPORARY
REDUCTIONS DURING PRECIPITATION.
AS HIGH PRESSURE SHIFTS EASTWARD OVERNIGHT, SOUTHERLY FLOW WILL
ESTABLISH ITSELF OVER THE REGION. CONVECTION IS FORECAST TO
INITIATE OVER IOWA AND MISSOURI TONIGHT, TRACKING EASTWARD INTO
CENTRAL ILLINOIS BETWEEN 09Z AND 15Z. WHILE THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE TERMINALS, THE COVERAGE IS
EXPECTED TO BECOME MORE ISOLATED AS THE MORNING PROGRESSES.
BREEZY SOUTHERLY WINDS WILL CHARACTERIZE FRIDAY'S WEATHER, WITH
SURFACE GUSTS REACHING SPEEDS OF 20-25 KTS, DIMINISHING AFTER
00Z.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...COPPLE
DISCUSSION...COPPLE
AVIATION...MJA
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