832
FXUS61 KCLE 171950
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
350 PM EDT WED JUN 17 2026
WHAT HAS CHANGED
CONFIDENCE IN ORGANIZED THUNDERSTORMS WITH A SEVERE WEATHER AND
HEAVY RAIN THREAT HAS DECREASED FOR TONIGHT. A WIND ADVISORY
HAS BEEN ISSUED FOR PORTIONS OF NORTHEAST OHIO AND NORTHWEST
PENNSYLVANIA FROM 12 AM TO 6 PM THURSDAY.
KEY MESSAGES
1) AFTER MAINLY LIGHT RAIN SPREADS IN THIS EVENING, SHOWERS AND
STORMS ARE EXPECTED ALONG A COLD FRONT LATE THIS EVENING INTO
OVERNIGHT TONIGHT. SOME OF THESE STORMS MAY BE SEVERE WITH
DAMAGING WINDS THE GREATEST CONCERN, THOUGH THE OVERALL SEVERE
RISK HAS TRENDED DOWN A LITTLE BIT TODAY.
2) SOUTHERLY WINDS BECOME GUSTY TONIGHT. WINDS SHIFT WEST-
SOUTHWEST ON THURSDAY AND REMAIN GUSTY THROUGH THE AFTERNOON. A
WIND ADVISORY IS IN EFFECT FOR PORTIONS OF NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA FROM 12 AM TO 6 PM THURSDAY.
3) BELOW NORMAL TEMPERATURES AND PERIODIC SHOWERS ARE POSSIBLE
THURSDAY THROUGH EARLY NEXT WEEK. THE GREATEST CHANCE OF RAIN
WILL BE SUNDAY INTO MONDAY.
DISCUSSION
KEY MESSAGE 1...
MAIN FOCUS IS CONVECTIVE POTENTIAL LATER THIS EVENING INTO THE
OVERNIGHT HOURS TONIGHT ALONG AND AHEAD OF A COLD FRONT THAT
WILL CROSS THE AREA. A BATCH OF RAIN THIS EVENING AHEAD OF ANY
CONVECTION MOVING IN FROM THE WEST, ALONG WITH TIMING LATE
EVENING INTO THE OVERNIGHT, LEADS TO CONSIDERABLE UNCERTAINTY
REGARDING SEVERE WEATHER POTENTIAL ACROSS THE LOCAL AREA.
A DECAYING BATCH OF STRATIFORM RAIN FROM EARLIER CONVECTION WELL
TO OUR WEST WILL MOVE EAST ACROSS OUR AREA LATE THIS AFTERNOON
AND EVENING AS A WARM FRONT QUICKLY SURGES THROUGH FROM THE
SOUTHWEST. AM NOT EXPECTING ANY SEVERE WEATHER OR EVEN MUCH (IF
ANY) LIGHTNING FROM THIS FIRST BATCH THIS EVENING.
THE MAIN FOCUS FOR CONVECTION WILL BE LATE EVENING AND OVERNIGHT
AS A COLD FRONT APPROACHES AND CROSSES OUR AREA FROM NORTHWEST
TO SOUTHEAST. AS HAS BEEN WRITTEN IN THIS SPACE MANY TIMES IN
RECENT DAYS, A VERY IMPRESSIVE AND DYNAMIC SYSTEM FOR THE MIDDLE
OF JUNE LEADING TO UNUSUALLY STRONG WIND FIELDS AND SHEAR FOR
THE SUMMER MONTHS. A 60-70KT LOW-LEVEL JET WILL SWEEP ACROSS
THE AREA TONIGHT AHEAD OF THE COLD FRONT. THIS WILL BRING PLENTY
OF BOTH BULK SPEED SHEAR AND LOW-LEVEL TURNING/STORM RELATIVE
HELICITY FOR ORGANIZED CONVECTION WITH POTENTIAL FOR ROTATING
UPDRAFTS. HOWEVER, AS MENTIONED ABOVE THE THERMODYNAMIC
ENVIRONMENT IS MUCH MORE QUESTIONABLE. GUIDANCE GENERALLY
SUGGESTS WE'LL HAVE AROUND 500 J/KG OF UNCAPPED (OR VERY WEAKLY
CAPPED) MLCAPE TO WORK WITH OVERNIGHT TONIGHT WITH MODEST LOW-
LEVEL LAPSE RATES BUT NO STRONG INVERSION, ONCE WE FINALLY GET
THE WARM FRONT THROUGH. WHILE THIS IS A MEAGER AMOUNT OF
INSTABILITY, 0-3KM CAPE VALUES IN THE ~50 J/KG RANGE AS
SUGGESTED BY MOST GUIDANCE ARE (BARELY) SUFFICIENT FOR SURFACE
BASED CONVECTION WITH AT LEAST SOME SEVERE THREAT. ASSUMING WE
SEE AT LEAST A BRIEF BREAK BETWEEN THE EVENING RAIN AND
APPROACHING COLD FRONT, THE OVERALL ENVIRONMENT CAN SUPPORT A
HIGH-SHEAR/LOW-CAPE SEVERE THREAT WITH ANY ORGANIZED CONVECTION.
IF WE DON'T SEE MUCH OF A BREAK IN THE RAIN WE WILL STRUGGLE TO
ADVECT IN EVEN THAT MODEST AMOUNT INSTABILITY.
IN TERMS OF IF WE'LL SEE ORGANIZED CONVECTION, HI-RES MODELS ALL
GENERALLY AGREE THAT CONVECTION WILL LOSE A GOOD AMOUNT OF
ORGANIZATION WELL BEFORE REACHING OUR NORTHWEST OHIO COUNTIES
LATER THIS EVENING...HOWEVER, SOME MODELS SUGGEST THAT AT LEAST
SCATTERED AND MAINLY WEAK (BUT SURFACE-BASED) CONVECTION WILL
PROGRESS EAST ACROSS OUR AREA THROUGH THE NIGHT AS INSTABILITY
ATTEMPTS ADVECTING IN. WHILE THE OVERALL SEVERE THREAT HAS
TRENDED DOWN AT LEAST SOMEWHAT GIVEN THE BATCH OF LIGHTER RAIN
EXPECTED THIS EVENING, THE FACT THAT A NUMBER OF MODELS HAVE AT
LEAST SOME SEMBLANCE OF SURFACE-BASED CONVECTION AMID SUCH
IMPRESSIVE SHEAR PROFILES IS ENOUGH THAT THE SPC OUTLOOK
MAINTAINS A SLIGHT RISK (LEVEL 2/5) FROM THE I-77 CORRIDOR
POINTS WEST FOR TONIGHT WITH A MARGINAL RISK (LEVEL 1/5) TO THE
EAST. DAMAGING WIND GUSTS ARE THE MOST LIKELY HAZARD IF WE SEE
ANY SEVERE THUNDERSTORMS TONIGHT. THE VERY STRONG SHEAR
PROFILES, LOW LCL HEIGHTS, AND MARGINAL 0-3KM CAPE CAN STILL
SUPPORT SOME TORNADO POTENTIAL FROM ANY SUPERCELLS OR SURGING
LINES, BUT THE LIKELY LACK OF ORGANIZED CONVECTION SHOULD KEEP
THAT RISK RELATIVELY LOWER. THE ENVIRONMENT DOES BECOME
SUPPORTIVE OF VERY HEAVY RAIN-RATES OVERNIGHT, BUT THE MORE
DISORGANIZED DEPICTION ON MANY MODELS KEEPS FLOODING POTENTIAL
TOO UNCERTAIN TO ISSUE ANY FLOOD WATCHES WITH THIS UPDATE.
THE TL;DR IS THAT SOME SHOWERS AND THUNDER ARE LIKELY ALONG AND
AHEAD OF THE COLD FRONT TONIGHT...ARRIVING AFTER 9 PM IN THE
TOLEDO AREA AND PROGRESSING EAST-SOUTHEAST THROUGH 3-5 AM. AT
LEAST AN ISOLATED SEVERE THREAT, MAINLY IN THE FORM OF DAMAGING
WIND GUSTS, REMAINS EVIDENT BUT WIDESPREAD/ORGANIZED SEVERE
WEATHER IS NOT LIKELY. TORNADOES CAN'T BE COMPLETELY RULED OUT,
NOR CAN LOCALLY HEAVY RAIN AND FLASH FLOODING, BUT THESE APPEAR
TO BE SECONDARY AND OVERALL VERY ISOLATED RISKS.
KEY MESSAGE 2...
WINDS WILL TURN GUSTY OVERNIGHT TONIGHT AS A VERY STRONG,
60-70KT LOW-LEVEL JET, SWEEPS EAST ACROSS THE AREA JUST AHEAD OF
THE COLD FRONT TONIGHT. THESE TYPES OF NOCTURNAL JETS USUALLY
DON'T MIX DOWN WELL IN A WARM ADVECTION REGIME, WITH THE NORMAL
EXCEPTION OF OUR DOWNSLOPE AREAS ALONG THE EASTERN LAKESHORE.
DOWNSLOPE ENHANCEMENT WILL BE MOST PROMINENT IN NORTHERN ERIE
COUNTY PA, BUT CAN HAPPEN TO AT LEAST SOME EXTENT AS FAR WEST AS
CLEVELAND. SOME HI-RES/CONVECTIVE ALLOWING MODELS ALSO SUGGEST
THE POTENTIAL FOR CONVECTIVE ENHANCEMENT (MOST LIKELY IN THE
FORM OF A "WAKE LOW" AS OCCURRED TO OUR WEST THIS AFTERNOON, BUT
POSSIBLY JUST FROM ENHANCED VERTICAL MOTION IN AND AROUND ANY
CONVECTION) BENEATH THE LOW-LEVEL JET. ANY ORGANIZED STORMS
THAT MAY PRODUCE DAMAGING WINDS WOULD BE HANDLED BY CONVECTIVE
PRODUCTS, THOUGH DO NOTE THERE MAY BE GENERALLY GUSTY WINDS NEAR
ANY WEAKENING CONVECTION FOR A BRIEF TIME. GENERALLY EXPECTING
A PERIOD OF 30-40 MPH WIND GUSTS AREA-WIDE BENEATH THE LOW-LEVEL
JET TONIGHT, BUT 45-50 MPH ALONG THE NORTHEAST LAKESHORE AND
PERHAPS BRIEFLY STRONGER ANYWHERE ELSE IF WE SEE ANY
MESOSCALE/CONVECTIVE PROCESSES TO ENHANCE THE GUSTS.
WINDS TURN MORE WEST-SOUTHWEST VERY LATE TONIGHT AND THURSDAY
BEHIND THE COLD FRONT. WINDS ALOFT GRADUALLY WEAKEN BEHIND THE
COLD FRONT BUT REMAIN FAIRLY STRONG (30-40KT AT 925MB, 35-45KT
AT 850MB) UNTIL EARLY-MID AFTERNOON AS MIXING HEIGHTS QUICKLY
INCREASE WITH DAYTIME HEATING. THESE WINDS WILL MIX DOWN MUCH
MORE EFFICIENTLY BEFORE DROPPING OFF LATE THURSDAY AFTERNOON AND
EVENING. AM EXPECTING FAIRLY WIDESPREAD 35-45 MPH TYPE WIND
GUSTS ON THURSDAY, UP TO 50 MPH CLOSER TO THE EASTERN LAKESHORE.
HAVE GONE AHEAD WITH A WIND ADVISORY FOR A HANDFUL OF COUNTIES
IN FAR NORTHEAST OH AND NORTHWEST PA, AS THIS AREA WILL SEE SOME
DOWNSLOPE ENHANCEMENT TO THE WIND TONIGHT AND WILL LIKELY SEE
SOME OF THE STRONGER WIND GUSTS ON THURSDAY. TOYED WITH AN
ADVISORY ELSEWHERE FOR VARIOUS REASONS, THOUGH CONFIDENCE IN
WIDESPREAD/COHERENT ADVISORY-LEVEL GUSTS TONIGHT IS NOT THERE
OUTSIDE OF THE DOWNSLOPING AND GUSTS TOMORROW MAY ALSO END UP
HOLDING A BIT BELOW CRITERIA AWAY FROM THE EASTERN LAKESHORE.
STILL, WE CAN START SEEING MINOR TREE DAMAGE AND ISOLATED POWER
OUTAGES WITH ~40 MPH GUSTS WHEN TREES ARE FULLY LEAFED OUT, SO
PEOPLE SHOULD BE PREPARED FOR GUSTY WINDS AND SOME MINOR IMPACTS
EVEN OUTSIDE OF THE ADVISORY. IF FORECAST GUSTS TICK UP ANY
MORE WE MAY NEED TO EXPAND THE ADVISORY INTO MORE OF THE AREA
GIVEN POSSIBLE IMPACTS.
KEY MESSAGE 3...
COLD AIR ADVECTION AND A TRAILING LOW-LEVEL TROUGH AXIS ON THE
BACK SIDE OF THE LOW WILL RESULT IN ISOLATED TO SCATTERED RAIN
SHOWERS THURSDAY INTO THURSDAY EVENING, ESPECIALLY DOWNWIND OF
LAKE ERIE. FROM THERE, DRY WEATHER IS EXPECTED BEFORE RAIN
CHANCES RETURN SUNDAY AFTERNOON THROUGH MONDAY. TEMPERATURES
WILL GENERALLY REMAIN A LITTLE BIT BELOW NORMAL OVER THE NEXT
SEVERAL DAYS WITH HIGHS IN THE 70S EXPECTED. LOWS WILL DROP INTO
THE 50S THURSDAY NIGHT THROUGH SATURDAY NIGHT.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
VFR CONDITIONS PERSIST ACROSS TERMINALS THIS AFTERNOON BEFORE A
DEEPENING LOW PRESSURE SYSTEM GLIDES ACROSS THE GREAT LAKES
REGION TONIGHT. INITIALLY EXPECT RAIN SHOWERS TO ENTER THE I-75
CORRIDOR FROM THE WEST AROUND 20Z/WED BEFORE ISOLATED CONVECTION
APPROACHES AROUND 00Z/THU. ANTICIPATE A SIMILAR TREND FROM WEST
TO EAST, THOUGH CONVECTION WILL LIKELY BE WEAKENING AS IT PUSHES
TOWARDS CENTRAL AND EASTERN TERMINALS DURING THE OVERNIGHT
HOURS. STRONG TO SEVERE THUNDERSTORMS REMAIN POSSIBLE,
PARTICULARLY ACROSS THE WESTERN TWO-THIRDS OF TERMINALS TONIGHT
AND DURING THE OVERNIGHT HOURS. STRONG WINDS AND A TORNADO WILL
BE THE PRIMARY CONCERN, THOUGH LARGE HAIL IS POSSIBLE.
CONDITIONS ARE EXPECTED TO FALL TO MVFR, ISOLATED IFR POSSIBLE,
THROUGH EARLY THURSDAY MORNING.
SOUTHERLY TO SOUTHWESTERLY WINDS AND GUSTS IN SHOWERS AND
THUNDERSTORMS TONIGHT WILL REMAIN ELEVATED WITH SUSTAINED WINDS
15-20 KNOTS AND GUSTS 25-35 KNOTS, POSSIBLY HIGHER IN SEVERE
THUNDERSTORMS. A STRONG LLJ WILL MOVE OVERHEAD AND HAVE
INTRODUCED A BRIEF WINDOW OF LLWS BEFORE THE BEST GUSTS MIX
DOWN TO THE SURFACE LATER THIS EVENING. NON-THUNDERSTORM
SOUTHWESTERLY TO WESTERLY WINDS AND GUSTS WILL REMAIN ELEVATED
BEHIND THE PASSING OF THE SURFACE COLD FRONT THROUGH THE DAY ON
THURSDAY.
OUTLOOK...PERIODIC SHOWERS AND THUNDERSTORMS WITH NON-VFR WILL
CONTINUE THROUGH FRIDAY.
MARINE
HAZARDOUS MARINE CONDITIONS ARRIVE THIS EVENING AS DEEPENING LOW
PRESSURE MOVES ACROSS THE GREAT LAKES REGION. AHEAD OF THE SURFACE
COLD FRONT, SOUTHERLY WINDS INCREASE TO 20-25 KNOTS BEFORE BECOMING
SOUTHWESTERLY AT 30-35 KNOTS BEHIND THE COLD FRONT LATE TONIGHT.
HAVE ISSUED A GALE WARNING FOR THE CENTRAL AND EASTERN BASINS AS
CONFIDENCE IN 35 KNOT SOUTHWEST GALES HAS INCREASED. THE GALE
WARNING REMAINS IN EFFECT FROM 2 AM THURSDAY THROUGH 6 PM THURSDAY.
WAVE HEIGHTS IN THE NEARSHORE WATERS ARE EXPECTED TO BUILD TO 3 TO 5
FEET IN THE WESTERN BASIN AND UP TO 6 TO 8 FEET ACROSS THE CENTRAL
AND EASTERN BASINS. A BEACH HAZARDS STATEMENT FOR A HIGH RISK OF RIP
CURRENTS REMAINS IN EFFECT ACROSS ALL LAKESHORE COUNTIES.
ADDITIONALLY, THERE IS ALSO A LOW WATER ADVISORY FOR THE WESTERN
BASIN FROM 4 AM TO 4 PM THURSDAY AS WATER LEVELS ARE EXPECTED TO
FALL BELOW THE CRITICAL MARK OF 13 INCHES IN THE STRONG
SOUTHWESTERLY FLOW.
MARINE CONDITIONS ARE EXPECTED TO IMPROVE ACROSS LAKE ERIE ON FRIDAY
AS WINDS TURN NORTHWEST AT 10-20 KNOTS WITH WAVE HEIGHTS GENERALLY
OF 2-4 FEET. AN ADDITIONAL ISSUANCE OF A SMALL CRAFT ADVISORY MAY BE
NEEDED TO COVER THE ONSHORE FLOW LATE THURSDAY NIGHT INTO FRIDAY
MORNING FOR THE CENTRAL AND EASTERN BASINS.
CLE WATCHES/WARNINGS/ADVISORIES
OH...BEACH HAZARDS STATEMENT FROM 8 PM EDT THIS EVENING THROUGH
THURSDAY EVENING FOR OHZ003-007-009>012-089.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT THURSDAY FOR
OHZ011>014-089.
PA...BEACH HAZARDS STATEMENT FROM 8 PM EDT THIS EVENING THROUGH
THURSDAY EVENING FOR PAZ001.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT THURSDAY FOR
PAZ001-002.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT
THURSDAY FOR LEZ142>144.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR LEZ145>149.
GALE WARNING FROM 2 AM TO 6 PM EDT THURSDAY FOR LEZ145>149-
165>169.
LOW WATER ADVISORY FROM 4 AM TO 4 PM EDT THURSDAY FOR
LEZ142>144-162>164.
DISCUSSION...SULLIVAN
AVIATION...13
MARINE...13
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