019
FXUS61 KILN 240657
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
257 AM EDT WED JUN 24 2026
WHAT HAS CHANGED
CONFIDENCE INCREASING IN CHANCES FOR EXCESSIVE RAINFALL LATE THIS
WEEK.
KEY MESSAGES
1) SHOWERS AND THUNDERSTORMS EXPECTED AT TIMES FROM THURSDAY THROUGH
SATURDAY, SOME POTENTIAL FOR HEAVY RAINFALL AND FLOODING, AND
POSSIBLY SOME SEVERE WEATHER.
2) TEMPERATURES INCREASING GOING INTO EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1) SHOWERS AND THUNDERSTORMS EXPECTED AT TIMES FROM
THURSDAY THROUGH SATURDAY, SOME POTENTIAL FOR HEAVY RAINFALL AND
FLOODING, AND POSSIBLY SOME SEVERE WEATHER.
SURFACE HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER OVER THE ILN
CWA FOR WEDNESDAY. THIS IS A RELATIVELY COOL AND DRY AIR MASS,
SUPPORTING MAX TEMPS AROUND 80 (SLIGHTLY BELOW NORMAL) AND DEWPOINTS
IN THE MID 50S. BY LATE TONIGHT, THE HIGH WILL BE MOVING OFF TO THE
EAST, AND THE OVERALL WEATHER PATTERN WILL BE SWITCHING TO ONE WITH
MORE SOUTHERLY FLOW -- AND THETA-E ADVECTION INTO THE OHIO VALLEY.
SOME SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE GREAT LAKES MAY
DRIFT INTO THE NORTHERN SECTIONS OF THE ILN FORECAST AREA EARLY
THURSDAY BEFORE DISSIPATING.
THE WESTERLY FLOW PATTERN WILL BECOME ACTIVE FROM THURSDAY THROUGH
SATURDAY, WITH OCCASIONAL SHOWERS AND THUNDERSTORMS EXPECTED. ALTHOUGH
TEMPERATURES WILL REMAIN BELOW NORMAL DURING THIS PERIOD, MOISTURE
WILL BE ON THE INCREASE, WITH DEWPOINTS GETTING INTO THE 60S TO NEAR
70. IT IS EXPECTED THAT THERE WILL BE A SURFACE FRONTAL ZONE
SOMEWHERE OVER THE ILN CWA DURING THIS TIME FRAME, PROVIDING SOME
CONVERGENCE AND A GRADIENT IN TEMPERATURES, WHICH MAY ACT AS A FOCUS
FOR THUNDERSTORM DEVELOPMENT. BROADER FORCING WILL OCCUR AS
SHORTWAVES IN THE WESTERLY FLOW MOVE ACROSS THE REGION. SOME OF THE
BIGGER SOURCES OF UNCERTAINTY IN THE FORECAST ARE INSTABILITY (LAPSE
RATES ARE NOT IMPRESSIVE, AND SBCAPE/MLCAPE NORTH OF THE BOUNDARY
WILL BE LOW) AND TIMING OF THE SHORTWAVES, ESPECIALLY FRIDAY AND
SATURDAY.
FOR THURSDAY, CONFIDENCE IS FAIRLY STRONG ON A WAVE SPARKING
THUNDERSTORM DEVELOPMENT OVER THE ILN CWA DURING THE AFTERNOON,
PERHAPS BECOMING MORE FOCUSED AS THE ACTIVITY MOVES EAST INTO PA/WV.
WITH SOME DECENT DEEP-LAYER SHEAR, COULD NOT RULE OUT A STRONGER
STORM, BUT INSTABILITY APPEARS MARGINAL (AROUND 1000 J/KG MLCAPE).
A GREATER POTENTIAL FOR STORMS WILL OCCUR AT SOME POINT FRIDAY AND
POSSIBLY INTO SATURDAY. MOST MODELS DEPICT SOME DEGREE OF WIDESPREAD
PRECIPITATION MOVING INTO THE AREA FRIDAY, THOUGH WITH VARYING
TIMING. SOME MODELS ALSO DEPICT A WEAK SURFACE LOW ASSOCIATED WITH
THE SHORTWAVE, WHICH COULD INCREASE BOTH FORCING AND LOW-LEVEL SHEAR
IF ONE WERE TO DEVELOP. NEITHER INSTABILITY OR SHEAR APPEAR TO BE ON
THE HIGHER END OF THE SCALE FOR FRIDAY, BUT A FEW STRONG TO SEVERE
STORMS APPEAR POSSIBLE. IF AN ORGANIZED MCS WERE TO DEVELOP AND RIDE
ALONG THE TEMPERATURE / CAPE GRADIENT, A SLIGHTLY GREATER DAMAGING
WIND POTENTIAL COULD OCCUR. FOR NOW, CONFIDENCE IN ANY EXACT SEVERE
SCENARIO IS LOW. CONFIDENCE IS A BIT HIGHER IN THE HEAVY RAINFALL
POTENTIAL, ESPECIALLY IF MULTIPLE ROUNDS OF STORMS PROGRESS IN THE
WESTERLY FLOW OVER THE WEST-TO-EAST SURFACE BOUNDARY. PRECIPITABLE
WATER VALUES MAY BE APPROACHING 2" BY FRIDAY, SO NOT ONLY WILL STORMS
HAVE THE POTENTIAL TO TRAIN, BUT RAIN RATES MAY ALSO BE QUITE HIGH.
CONVECTION SHOULD GENERALLY TREND SOUTHWARD FROM FRIDAY TO SATURDAY,
AND CONFIDENCE IS VERY LOW IN ANY SPECIFICS, BUT SOME ADDITIONAL
STRONG STORMS AND HEAVY RAIN COULD OCCUR SATURDAY AS WELL. THIS WOULD
BE MORE LIKELY FOR THE SOUTHERN SECTIONS OF THE ILN CWA.
KEY MESSAGE 2) TEMPERATURES INCREASING GOING INTO EARLY NEXT WEEK.
PRECIPITATION CHANCES WILL BE DIMINISHING BY THE SECOND HALF OF THE
WEEKEND, WITH A BIG PATTERN CHANGE FORECAST TO TAKE PLACE. RIDGING IS
FORECAST TO BUILD THROUGH THE EASTERN CONUS, PUTTING THE OHIO VALLEY
IN AN AIR MASS THAT WILL BE INCREASINGLY HOT AND HUMID. THUS, THE
MAIN CONCERN FOR NEXT WEEK WILL BE THE POTENTIAL FOR HEAT TO REACH
HAZARDOUS LEVELS. THERE IS HIGH CONFIDENCE THAT SURFACE TEMPERATURES
WILL AT LEAST REACH THE UPPER 80S ACROSS THE AREA BY MONDAY AND
TUESDAY, AND MEDIUM CONFIDENCE THAT TEMPERATURES WILL GET INTO THE
90S. WITH DEWPOINTS IN THE LOWER 70S, HEAT INDEX VALUES NEAR OR ABOVE
100 WILL BE POSSIBLE.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE TAF PERIOD. THE
EXCEPTION WILL BE SOME FOG AT KCVG/KLUK/KILN EARLY THIS MORNING. ANY
FOG THAT DEVELOPS WILL IMPROVE QUICKLY AFTER 12Z.
SCATTERED CUMULUS CLOUDS, AND A FEW HIGH CLOUDS, ARE EXPECTED TODAY.
SOME MID LEVEL CLOUDS WILL MOVE INTO THE AREA TONIGHT. WINDS,
INITIALLY LIGHT, WILL BE OUT OF THE SOUTHWEST THIS AFTERNOON AT UNDER
10 KNOTS.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE AT TIMES FROM THURSDAY THROUGH
SATURDAY. MVFR CONDITIONS ARE POSSIBLE FRIDAY.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...NONE.
IN...NONE.
DISCUSSION...HATZOS
AVIATION...HATZOS
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