041
FXUS61 KILN 182330
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
730 PM EDT SAT JUL 18 2026
WHAT HAS CHANGED
THE SEVERE THREAT IS LOWER.
KEY MESSAGES
KEY MESSAGE 1) A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE REGION
THIS AFTERNOON INTO TONIGHT. THIS WILL BRING PERIODIC THUNDERSTORMS,
AND A FEW OF THE STORMS MAY BECOME SEVERE WITH DAMAGING WIND THE
MAIN THREAT.
KEY MESSAGE 2) ANOTHER COLD FRONT WILL MOVE THROUGH THE REGION ON
TUESDAY. THIS WILL BRING THE NEXT CHANCE FOR THUNDERSTORMS AND USHER
IN A SOMEWHAT COOLER AIRMASS FOR MID TO LATE NEXT WEEK.
DISCUSSION
KEY MESSAGE 1)
PREFRONTAL ATMOSPHERE THUNDERSTORMS SUPPORTED BY MLCAPE VALUES OF
2000 J/KG, THOUGH DCAPE VALUES CURRENTLY IN THE 500-700 J/KG RANGE.
ENOUGH FOR SOME STORMS TO GUST TO NEAR 40-45MPH, SO AN AFTERNOON
SEVERE STORM CERTAINLY IS POSSIBLE. CLOUDS ARE ON THE INCREASE WITH
THE AFTERNOON CONVECTION, BUT WHERE SIGNIFICANT BREAKS IN THE CLOUDS
AND AMPLE LOW LEVEL MOISTURE/HIGH DEWPOINTS, HEAT INDEX VALUES ARE
FROM 95 TO EVEN 100 IN SOME AREAS. WITH INCREASED CONVECTION/CLOUDS,
THIS SHOULD BE SLIGHTLY TEMPERED AS THE AFTERNOON PROGRESSES.
MAIN SHOW WILL BE WITH THE SOUTHERN GREAT LAKES SHORT WAVE AND
ASSOCIATED COLD FRONT PUSHING TOWARD THE REGION LATE THIS AFTERNOON.
SHEAR WILL INCREASE WITH THE APPROACHING FRONTAL BOUNDARY, WITH 0-3KM
VALUES BUMPING UP TO 25-30KTS, AND 0-1KM SHEAR NEARING 20KTS IN
NORTHERN REACHES OF CENTRAL OHIO. WHILE CURRENT CONVECTION COULD
DIMINISH AVAILABLE INSTABILITY ONCE THE ORGANIZED LINE APPROACHES THE
REGION, THERE WILL STILL BE INCREASED LOW LEVEL SHEAR. STILL LOOKING
AT THE MAIN THREAT BEING DAMAGING WINDS, BUT WHERE LL SHEAR IS
ENHANCED IN CENTRAL OHIO A TORNADO IS POSSIBLE.
PW VALUES OF 1.9-2.1 ARE NEAR THE CLIMATOLOGICAL MAX FOR THE AREA, SO
RAPID ACCUMULATIONS OF 1" IN LESS THAN 1 HOUR COULD CREATE ISOLATED
FLOODING. THE STORMS SHOULD BE PROGRESSIVE IN NATURE, THOUGH, SO
FLOODING WILL BE A SECONDARY THREAT.
KEY MESSAGE 2)
WITH UPPER LEVEL NW FLOW DOMINATING THE REGION FOR SUNDAY AND MONDAY,
A QUIET START TO THE WORK WEEK. FOR MONDAY NIGHT INTO TUESDAY,
ANOTHER STRONGER GREAT LAKES SHORT WAVE WILL PUSH INTO THE REGION,
BRINGING A RENEWED CHANCE OF THUNDERSTORMS. INCREASING ML CAPE AND
0-6KM BULK SHEAR WOULD BRING A POTENTIAL FOR SEVERE STORMS ON
TUESDAY. ONCE THIS SHORTWAVE PUSHES THROUGH, A SLIGHTLY COOLER AND
MORE STABLE AIRMASS SETTLES INTO THE AREA FOR MID/LATE WEEK.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
CLUSTERS OF THUNDERSTORMS HAVE DEVELOPED ALONG A PRE-FRONTAL TROF
MOVING INTO ILN/S NORTHERN COUNTIES. AN AXIS OF DCAPE VALUES OF
1000-1200 J/KG IS SUPPORTIVE OF GUSTY TO DAMAGING WINDS MAINLY OVER
AREAS ALONG AND NORTH OF I-70 - WITH THE BEST OVERLAP OF SHEAR AND
INSTABILITY OVER CENTRAL OHIO. THE STORMS ARE MOVING SOUTHEAST INTO
AN AIR MASS THAT HAS BEEN OVERTURNED FROM EARLIER CONVECTION WHICH
SUPPORTS A GENERAL WEAKENING OF STORM STRENGTH. THIS EXPECTED GRADUAL
DECREASE IN STORM STRENGTH WILL LIMIT THE SEVERE THREAT.
HAVE TEMPO GROUPS FOR THUNDER FOR THE CENTRAL OHIO TAF/S WITH A PROB30
AT ALL OTHER SITES FOR THE NEXT FEW HOURS. THE POTENTIAL FOR BRIEF
MVFR CIGS AND VSBYS EXISTS THIS EVENING, ALONG WITH SOME NORTHWEST
GUSTY WINDS. AS THE FRONT SAGS SOUTH OF THE AREA AFTER 04Z, WINDS
VEER TO THE NORTHWEST AND NORTH AND DROP OFF A BIT. SOME VISIBILITY
RESTRICTIONS ARE POSSIBLE AT THE MORE FOG PRONE LOCATIONS OF KLUK AND
KILN.
ANY FOG THAT DEVELOPS WILL IMPROVE EARLY SUNDAY MORNING WITH A GOOD
SIGNAL FOR VFR CUMULUS CLOUDS. THERE ARE SOME INDICATIONS THAT SMOKE
MAKE RESULT IN HAZY CONDITIONS. HAVE NOT RESTRICTED VSBYS AT THIS
TIME DUE TO UNCERTAINTY REGARDING IMPACTS.
OUTLOOK...THUNDERSTORMS POSSIBLE TUESDAY.
ILN WATCHES/WARNINGS/ADVISORIES
OH...AIR QUALITY ALERT FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT MONDAY
NIGHT FOR OHZ042-043-051-060>062.
KY...NONE.
IN...AIR QUALITY ALERT FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT MONDAY
NIGHT FOR INZ050-058-059-066.
DISCUSSION...JDR
AVIATION...AR
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