804
FXUS63 KILX 301040
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
540 AM CDT SAT MAY 30 2026
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES ARE LIKELY TO PERSIST INTO MID-JUNE, WITH
HIGHS IN THE 80S OVER THE NEXT WEEK.
- THERE IS A 30-50% CHANCE FOR SHOWERS AND STORMS SUNDAY NIGHT
INTO MONDAY, WITH CHANCES HIGHEST WEST OF THE ILLINOIS RIVER.
OTHERWISE, MOSTLY DRY CONDITIONS ARE EXPECTED THROUGH MUCH OF
NEXT WEEK.
DISCUSSION
ISSUED AT 245 AM CDT SAT MAY 30 2026
THE UPPER PATTERN REMAINS AMPLIFIED, WITH AN OMEGA BLOCK IN
PLACE IN THE FORM OF UPPER LOWS OVER THE WESTERN US AND NEW
ENGLAND AND A RIDGE AXIS EXTENDING FROM THE MIDWEST WELL INTO
CENTRAL CANADA. SFC HIGH PRESSURE OVER ONTARIO WILL EXPAND
SOUTHWARD TODAY. BETWEEN THIS SFC HIGH AND LEE CYCLOGENESIS IN
RESPONSE TO THE WESTERN US TROUGH, WINDS WILL MAINTAIN AN
EASTERLY COMPONENT ACROSS CENTRAL IL AND LIMIT MOISTURE
ADVECTION. STILL, A FEW SHOWERS CAN'T BE RULED OUT THIS
AFTERNOON AS WELL AS OVERNIGHT ALONG A STALLED FRONTAL
BOUNDARY/MOISTURE GRADIENT OVER WESTERN IL. THE LATEST CAMS KEEP
MOST OF THIS ACTIVITY JUST WEST OF THE ILX CWA, BUT THERE'S
ENOUGH SIGNAL TO MAINTAIN LOW POPS (15-20%) WEST OF A GALESBURG-
TO- SPRINGFIELD LINE. PRECIP ACTIVITY WILL STRUGGLE TO MAKE IT
ANY FURTHER EAST DUE TO THE DIMINISHING MOISTURE CONTENT. THE
INSTABILITY AND WIND SHEAR VALUES ARE BOTH MARGINAL AT BEST,
WITH MUCAPE LESS THAN 800 J/KG AND DEEP LAYER SHEAR LESS THAN 25
KTS, THUS SEVERE STORMS ARE NOT EXPECTED.
THE NBM HAS BEEN TOO COOL WITH THE HIGH TEMP FORECAST OVER THE
LAST SEVERAL DAYS, AND DESPITE CLOUD COVER YESTERDAY WAS NO
EXCEPTION. EVEN WITH CLOUDS PRESENT AGAIN TODAY, OPTED TO NUDGE
HIGHS A FEW DEGREES WARMER THAN THE NBM AS THE EASTERLY FLOW
PROMOTES DRY LOW- LEVELS. TEMPS OFTEN OVERPERFORM GUIDANCE ON
THESE DRY DAYS, ESPECIALLY EARLY IN THE PLANTING SEASON WHEN
EVAPOTRANSPIRATION IS MINIMAL AND THE SUN'S ENERGY IS PRIMARILY
FOCUSED INTO SENSIBLE HEAT FLUX. OUR LATEST FORECAST HAS HIGHS
IN THE MID 80S, BUT I WOULDN'T BE SURPRISED IF SAW READINGS
CREEP INTO THE UPPER 80S ONCE AGAIN.
THE INFLUENCE OF THE SFC HIGH PRESSURE TO OUR NORTHEAST WEAKENS
INTO SUN NIGHT, OPENING THE DOOR FOR PRECIP TO NUDGE EAST INTO
OUR AREA AS ADDITIONAL WEAK DISTURBANCES EMANATE AROUND THE
WESTERN US TROUGH. EXACTLY HOW FAR EAST ANY RAIN MANAGES TO MAKE
IT REMAINS LOW CONFIDENCE, BUT FOR NOW THE LATEST MODEL BLEND
DELIVERED 20-50% POPS EAST OF I-57 SUNDAY NIGHT, HIGHEST WITH
WESTWARD EXTENT, WHICH SEEMED REASONABLE. SCATTERED STORMS COULD
LINGER INTO MONDAY. A MODEST UPTICK IN THE WIND SHEAR AND AN
EASTWARD PIVOT IN THE INSTABILITY AXIS COULD PROMOTE A FEW
STRONG STORMS, MAINLY SOUTHWEST OF A MACOMB-TO-SPRINGFIELD LINE.
HAIL AND WIND WOULD BE THE MAIN CONCERNS WITH ANY SUCH STORMS.
INTO EARLY NEXT WEEK, THE UPPER RIDGE STRENGTHS AND YET ANOTHER
RENEWED PUSH OF SFC HIGH PRESSURE OCCURS OVER THE GREAT LAKES.
THE ASSOCIATED HEIGHT RISES/SUBSIDENCE SHOULD KEEP THE REGION
DRY TUES- WED (AND LIKELY INTO THURS AS WELL). TEMPS REMAIN
ABOVE NORMAL, WITH THE LATEST NBM DEPICTING HIGHS IN THE LOW TO
MID 80S. GIVEN THE RECENT COOL BIAS AND AMPLE SUNSHINE EXPECTED
MID- WEEK, SUSPECT THAT WE WILL CONTINUE TO OUTPERFORM THE NBM
FORECAST. THE NBM 90TH PERCENTILE (10% CHANCE OF HIGHER VALUES)
HAS HIGH TEMPS IN THE MID TO UPPER 80S (OR PERHAPS LOW 90S BY
THURS), AND THESE VALUES MAY WIND UP BEING CLOSER TO REALITY
THAN THE CURRENT FORECAST.
DEWPOINTS REMAIN LOW DURING THE MID-WEEK PERIOD, ESPECIALLY IN
THE SCENARIOS WHERE WE OVERPERFORM ON TEMPS. THE LATEST BLEND
HAS AFTERNOON DEWPOINTS AROUND 50F ON TUES-WED. HOWEVER, THAT
MAY CHANGE BY LATE NEXT WEEK, AS MODELS DEPICT AN EXPANSIVE SFC
HIGH FINALLY SHIFTING EAST OF OUR AREA, RATHER THAN BEING
POSITIONED TO THE NORTH, WHICH WOULD INTRODUCE SOUTHERLY FLOW
AND INCREASING HUMIDITY. ABOVE NORMAL TEMPS APPEAR LIKELY TO
CONTINUE INTO THE EXTENDED FORECAST, WITH THE CPC HIGHLIGHTING
THE ENTIRE STATE OF IL AS HAVING A SLIGHT RISK OF EXTREME HEAT,
VALID FROM NEXT SATURDAY (JUNE 6) INTO THE SECOND WEEK OF JUNE.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 537 AM CDT SAT MAY 30 2026
NO MEANINGFUL CHANGES WERE NECESSARY WITH THIS TAF UPDATE. VFR
CONDITIONS ARE SET TO PREVAIL THROUGH THE PERIOD, WITH BROKEN
HIGH LEVEL CLOUD COVER. EASTERLY WINDS WILL INCREASE TO AROUND
10-15 KTS BY MID-MORNING, WITH SOME WEAKENING POSSIBLE TOWARDS
THE VERY END OF THE PERIOD.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...ERWIN
DISCUSSION...ERWIN
AVIATION...ERWIN
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