767
FXUS61 KCLE 151130
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
730 AM EDT SAT AUG 15 2026
WHAT HAS CHANGED
THE RISK FOR SEVERE THUNDERSTORMS HAVE DECREASED FOR TONIGHT,
WHILE INCREASES FOR SUNDAY. THERE IS A MARGINAL RISK FOR SEVERE
THUNDERSTORMS ON SUNDAY ACROSS MOST OF THE AREA.
KEY MESSAGES
1) SHOWERS AND THUNDERSTORMS ARE EXPECTED AT TIMES THROUGH
SUNDAY NIGHT. HEAVY RAIN MAY CAUSE LOCALIZED FLOODING TONIGHT
THROUGH SUNDAY EVENING. STRONGER STORMS SUNDAY AFTERNOON MAY
PRODUCE DAMAGING WINDS THOUGH AN ISOLATED TORNADO CANNOT BE
RULED OUT.
2) RAIN-FREE CONDITIONS WITH HIGH PRESSURE ARE LIKELY MONDAY
AFTERNOON THROUGH TUESDAY NIGHT BEFORE SHOWERS AND THUNDERSTORMS
RETURN WEDNESDAY.
DISCUSSION
KEY MESSAGE 1...
A STATIONARY FRONT LOCATED WELL TO OUR SOUTH IN THE LOWER OHIO
VALLEY WILL LIFT NORTH ACROSS THE AREA TONIGHT IN RESPONSE TO
LOW PRESSURE MOVING EASTWARD ACROSS THE GREAT LAKES REGION.
SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED
AREAWIDE THROUGH AT LEAST SUNDAY EVENING, WHEN THE COLD FRONT
SWEEPS SOUTHEASTWARD ACROSS THE AREA.
A COMPLEX OF THUNDERSTORMS CURRENTLY LOCATED IN CENTRAL
ILLINOIS WILL GRADUALLY SHIFT EASTWARD THROUGH THE DAY, WITH
MOST MODEL GUIDANCE INITIALLY PRESENTING THIS AS LIGHT ISOLATED
TO SCATTERED RAIN SHOWERS SPREADING EASTWARD THROUGH THE DAY
SATURDAY, WELL AHEAD OF THE WARM FRONT ALOFT. AT SOME POINT LATE
THIS EVENING INTO TONIGHT, SHOULD BE CONVECTIVE REDEVELOPMENT
AS THE 850MB THETA-E GRADIENT SHIFTS EASTWARD, AND THE LLJ
STRENGTHENS BEHIND IT. CONVECTION IS LIKELY TO FOCUS ALONG OUR
SOUTHWEST COUNTIES TONIGHT. ANY CONVECTION THAT DEVELOPS TONIGHT
WOULD POSE A FLASH FLOODING RISK DUE TO PWAT VALUES IN THE
2-2.5" (NEAR A CLIMATOLOGICAL MAX), WHICH WOULD SUPPORT
EFFICIENT, HEAVY RAINFALL. THERE IS SIGNIFICANT UNCERTAINTY WITH
PLACEMENT AND COVERAGE OF CONVECTION TONIGHT, AIDED BY RUN- TO-
RUN VARIABILITY. COMPARED TO THE 12Z GUIDANCE, MOST OF THE
LATEST 00Z MODELS HAVE BACKED OFF ON LLJ STRENGTH, AND QPF
AMOUNTS BY QUITE A BIT TONIGHT. THIS TREND (AND GENERAL MODEL
GUIDANCE VOLATILITY) PRECLUDES THE ISSUANCE OF A FLOOD WATCH
FOR THE TIME BEING, THOUGH WE WILL CONTINUE TO MONITOR LATEST
FORECAST TRENDS TO SEE IF ONE MAY BE NEEDED. IF ONE WERE NEEDED,
IT IS MOSTLY NEEDED FOR OUR SOUTHWEST COUNTIES (E.G. HANCOCK TO
KNOX COUNTIES), WHERE THE FLOODING RISK IS GREATEST.
WHILE HEAVY RAIN AND FLOODING RISK ARE THE PRIMARY WEATHER
HAZARDS, STRONG WIND GUSTS AND A WEAK TORNADO CANNOT BE RULED
OUT THIS EVENING INTO TONIGHT, PARTICULARLY FOR OUR SOUTHWEST
COUNTIES (E.G. HANCOCK TO KNOX COUNTIES).
ADDITIONAL CONVECTION IS EXPECTED THROUGHOUT THE DAY SUNDAY
BEFORE THE COLD FRONT SWEEPS THROUGH SUNDAY EVENING, THOUGH THE
EVOLUTION IS EVEN MORE UNCERTAIN. IN GENERAL THOUGH, EXPECT
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS AFFECTING THE ENTIRE
FORECAST AREA. HIGH PWAT EXCEEDING 2" WILL PROVIDE A FAVORABLE
ENVIRONMENT FOR HEAVY RAIN, LEADING TO LOCALIZED FLOODING.
MUCAPE > 1500 J/KG AND DEEP LAYER SHEAR AROUND 30 KNOTS WOULD
SUPPORT SEVERE WEATHER (PRIMARY HAZARDS ARE DAMAGING WINDS AND
PERHAPS A WEAK TORNADO), THOUGH THIS IS A SECONDARY HAZARD TO
THE HEAVY RAIN AND FLOODING THREAT.
ISOLATED TO SCATTERED RAIN SHOWERS MAY LINGER SUNDAY NIGHT INTO
MONDAY MORNING ACROSS NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA.
KEY MESSAGE 2...
HIGH PRESSURE WILL BRING RAIN-FREE CONDITIONS TO THE REGION
MONDAY AFTERNOON THROUGH TUESDAY NIGHT. A WEAK LOW PRESSURE
SYSTEM WILL MOVE ACROSS THE GREAT LAKES REGION, BRINGING
SCATTERED SHOWERS AND THUNDERSTORM TO THE REGION ON WEDNESDAY.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
ANY REMAINING PATCHY FOG WILL DISSIPATE WITHIN THE FIRST HOUR OR
TWO OF THE TAF PERIOD AND VFR IS EXPECTED THROUGH THIS
AFTERNOON AND POSSIBLY INTO THIS EVENING. ISOLATED LIGHT SHOWERS
CAN'T BE RULED OUT ACROSS THE AREA BETWEEN ROUGHLY 12Z AND 18Z
TODAY, BUT CONFIDENCE IN PLACEMENT/COVERAGE IS TOO LOW TO
INCLUDE IN THE TAFS AT THIS POINT. EVEN IF IT DOES RAIN,
SIGNIFICANT IMPACTS TO FLIGHT CONDITIONS ARE NOT ANTICIPATED.
CONFIDENCE IN THE EVENING AND OVERNIGHT CONVECTION IS STILL
PRETTY LOW AT THIS POINT SO HAVE BROAD SHOWERS WITH PROB30
GROUPS FOR THUNDERSTORMS. RAIN WILL LIKELY LINGER THROUGH EARLY
SUNDAY MORNING, ESPECIALLY AT SOUTHERN TERMINALS. WILL NEED TO
MAKE AMENDMENTS AND UPDATES AS CONFIDENCE INCREASES THROUGHOUT
THE DAY. EITHER WAY, ANY EVENING AND OVERNIGHT SHOWERS/STORMS
COULD PRODUCE NON-VFR CONDITIONS IN MODERATE TO HEAVY RAIN AND
LOWER CEILINGS. WINDS WILL BE LIGHT AND VARIABLE TODAY WITH
WINDS BECOMING MORE SOUTHWESTERLY AND INCREASING TO 5 TO 10
KNOTS AFTER 06Z SUNDAY.
OUTLOOK...NON-VFR POSSIBLE WITH PERIODIC SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY NIGHT. ADDITIONAL NON-VFR POSSIBLE
IN SHOWERS AND THUNDERSTORMS WEDNESDAY.
MARINE
EAST/SOUTHEAST WINDS 10 KNOTS OR LESS ARE EXPECTED THROUGH EARLY
THIS AFTERNOON BEFORE EAST WINDS INCREASE TO 10 TO 15 KNOTS THIS
EVENING THROUGH TONIGHT. WINDS WILL SHIFT TO THE SOUTHWEST ON
SUNDAY WITH FLOW BECOMING NORTHWESTERLY SUNDAY NIGHT THROUGH
MONDAY. MAY NEED TO CONSIDER SMALL CRAFT ADVISORIES/BEACH
HAZARDS STATEMENTS IF ONSHORE WINDS TREND HIGHER, BUT AS OF NOW
WINDS/WAVES SHOULD REMAIN BELOW CRITERIA. WINDS WILL BE OUT OF
THE SOUTHWEST ON TUESDAY AND WEDNESDAY WITH OFFSHORE WINDS
POSSIBLY REACHING 15 TO 20 KNOTS IN THE WESTERN BASIN AS A COLD
FRONT APPROACHES LAKE ERIE.
CLE WATCHES/WARNINGS/ADVISORIES
OH...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR OHZ036>038-
047.
PA...NONE.
MARINE...NONE.
DISCUSSION...SAUNDERS
AVIATION...15
MARINE...15
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