187
FXUS61 KCLE 100720
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
320 AM EDT MON AUG 10 2026
WHAT HAS CHANGED
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE
ACROSS THE REGION THROUGH WEDNESDAY. CONFIDENCE IS INCREASING IN
MOST OF THESE ROUNDS AT LEAST IMPACTING THE SOUTHWEST HALF OF THE
FORECAST AREA (ROUGHLY ALONG AND SOUTHWEST OF A BOWLING GREEN TO
CANTON LINE) WITH THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
REPEATED ROUNDS OF HEAVY RAIN, WHICH MAY LEAD TO FLASH FLOODING.
THERE IS STILL SOME UNCERTAINTY ON HOW MUCH SEVERE WEATHER AND
FLOODING POTENTIAL THERE WILL BE IN THE NORTHEAST HALF OF THE AREA,
AS THIS WILL BE DICTATED BY THE FRONT LOCATION WITH EACH BATCH OF
STORMS THAT MOVES THROUGH THE REGION.
KEY MESSAGES
1) SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE
ACROSS THE REGION THROUGH WEDNESDAY. EACH ROUND WILL HAVE THE
POTENTIAL TO BRING HEAVY RAINFALL, WHICH COULD LEAD TO LOCALIZED
FLOODING, AND SCATTERED SEVERE THUNDERSTORMS WITH DAMAGING WIND
GUSTS AS THE PRIMARY THREAT.
2) DRY WEATHER IS EXPECTED ON THURSDAY AND FRIDAY, GIVING A BREAK IN
THE ACTIVE PATTERN. TEMPERATURES AND HUMIDITY WILL TAPER OFF WITH
HIGH PRESSURE ENTERING THE REGION.
3) UNSETTLED WEATHER MAY RETURN FOR THE WEEKEND WITH MORE SCATTERED
SHOWER AND STORM CHANCES ACROSS THE GREAT LAKES REGION ON SATURDAY
AND SUNDAY.
DISCUSSION
KEY MESSAGE 1...
WITH ONE ROUND OF SHOWERS AND STORMS EXITING STAGE RIGHT INTO
PA, ALL ATTENTION TURNS BACK TO THE WEST AS A NEW COMPLEX HAS
DEVELOPED ACROSS NORTHERN ILLINOIS INTO SOUTHWESTERN LOWER
MICHIGAN. THIS AREA OF SHOWER AND STORM ACTIVITY IS BEING FUELED
BY THE WARM AIR ADVECTION ENTERING THE REGION WITH THE FRONT
LIFTING BACK NORTH AFTER THE FIRST ROUND OF ACTIVITY. IN
ADDITION, A POTENT LOW LEVEL JET WITH 30 TO 35 KT OF 925 MB FLOW
WILL PROVIDE EXTRA SUPPORT FOR STORM ACTIVITY. THE MAIN
QUESTION WITH THIS COMPLEX IS: WHERE IS IT GOING? THE ACTIVITY
SOUTH OF CHICAGO IS TRYING TO FOLLOW THE INSTABILITY GRADIENT
AND SHOULD ALLOW FOR THIS ACTIVITY TO DIVE MORE SOUTHEAST INTO
INDIANA AND POTENTIALLY SOUTHWEST OHIO. THIS CLUSTER SHOULD
REMAIN OUT OF THE FORECAST AREA. THE MORE CONCERNING PORTION OF
THE COMPLEX ARE THE STORMS OVER SOUTHWESTERN LOWER MICHIGAN.
STORMS ARE PRESENTLY MOVING IN A NORTHEASTERLY DIRECTION.
MEANWHILE, STORMS CLOSER TO GRAND RAPIDS ARE MORE TIED TO A
BOUNDARY THAT ARCS SOUTHEAST INTO NORTHERN OHIO. OVER THE NEXT
COUPLE OF HOURS, EXPECT THESE STORMS TO CONGEAL OVER SOUTHERN
MICHIGAN. IF THEY CAN ORGANIZE A TOUCH AND FORM A COLD POOL,
THESE STORMS DO HAVE THE POTENTIAL TO MOVE SOUTHEAST AND PUSH
TOWARD THE FORECAST AREA LATER THIS MORNING. IF THESE STORMS
JUST REMAIN FORCED BY THE LOW LEVEL JET AND END UP STAYING TIED
TO THE SURFACE BOUNDARY, THEN IT IS POSSIBLE THAT THIS BATCH
COULD MISS MUCH OF THE AREA TO THE NORTH OR AT LEAST MOVE
OVER/ALONG LAKE ERIE. THERE IS SOME ELEVATED INSTABILITY TO
WORK WITH AHEAD OF THIS COMPLEX AND PRECIPITABLE WATER VALUES
AROUND 1.75" DEPICT THAT RAIN COULD HAVE SOME EFFICIENCY. STORMS
SHOULD ALSO QUICKLY PERK UP WITH DAYTIME HEATING AS THESE WILL
MOVE THROUGH THE REGION AS THE SUN RISES AND ACTIVITY COULD
BECOME CONCERNING QUICKLY AFTER DAYBREAK ONCE THE LOW LEVEL
INVERSION MIXES OUT.
THIS MORNING ROUND OF SHOWERS AND THUNDERSTORMS WILL THEN DICTATE
HOW THE REST OF THE DAY WILL EVOLVE. IF THE ACTIVITY GOES THROUGH
MOST OF THE FORECAST AREA, THEN THE FRONT WILL BE SOUTH OF THE AREA
AND NEW ACTIVITY WOULD NOT BE FAVORED DURING THE DAYTIME HOURS. IF
THE MORNING ACTIVITY STAYS NORTH OR JUST STAYS NEAR LAKE ERIE, THEN
MOST OF THE FORECAST AREA WILL REMAIN SOUTH OF THE FRONT IN A
CONDITIONALLY UNSTABLE AIRMASS WITH WARM ADVECTION ACROSS THE AREA.
THIS WOULD THEN ALLOW FOR SCATTERED SHOWER AND STORM ACTIVITY TO
DEVELOP OVER THE AREA DURING THE AFTERNOON AND EVENING HOURS. STORMS
WOULD THEN HAVE THE POTENTIAL FOR STRONG TO DAMAGING WIND GUSTS AND
HEAVY RAIN THAT COULD BRING LOCALIZED FLOODING. THESE STORMS COULD
PERSIST INTO TONIGHT.
FOR TONIGHT, ALL ATTENTION RETURNS BACK TO WISCONSIN AND ILLINOIS
FOR THE DEVELOPMENT OF A NEW COMPLEX OF SHOWERS AND THUNDERSTORMS
THAT WILL MOVE SOUTHEAST ALONG THE FRONT. AGAIN, THE LOCATION OF THE
FRONT WILL BE VERY IMPORTANT ON WHERE THIS COMPLEX WILL GO - EITHER
INTO OUR AREA OR TO THE SOUTHWEST. IF THERE IS ALREADY ACTIVITY IN
OUR AREA THIS AFTERNOON AND EVENING, THEN THIS COMPLEX WILL STAY
SOUTHWEST BUT THERE WILL ALREADY BE ACTIVITY OVERHEAD TO CONTEND
WITH. IF THE AREA IS DRY, THEN THERE IS A GREATER CHANCE OF THIS
COMPLEX REACHING THE FORECAST AREA. THE AVERAGE SOLUTION SUGGESTS
THAT AT LEAST THE SOUTHWEST HALF OF THE FORECAST AREA (ROUGHLY ALONG
AND SOUTHWEST OF A LINE FROM BOWLING GREEN TO CANTON) SHOULD GET
SOME ACTIVITY TONIGHT.
FOR TUESDAY, ANOTHER SOUTHEASTWARD DIVING MCS IS EXPECTED TO DEVELOP
WEST OF THE FORECAST AREA DURING THE MORNING HOURS. THIS COMPLEX
SHOULD REACH THE AREA DURING THE AFTERNOON HOURS, FAVORING THE
SOUTHWEST PORTION OF THE FORECAST AREA, ROUGHLY ALONG AND SOUTHWEST
OF A FINDLAY TO MILLERSBURG LINE. GIVEN THAT THIS COMPLEX WILL MOVE
THROUGH PEAK HEATING HOURS WITH MAXIMUM INSTABILITY, THERE SHOULD BE
A SEVERE WIND THREAT THAT WILL MATERIALIZE WITH THIS COMPLEX.
MEANWHILE, FORECAST SOUNDINGS AHEAD OF THIS COMPLEX SHOW
PRECIPITABLE WATER VALUES CREEPING BACK UP TO 1.80" SHOWING THAT
THIS COMPLEX WILL BRING MORE HEAVY RAIN TO THE AREA. WITH THIS
POTENTIALLY BEING THE THIRD OR FOURTH ROUND OF RAIN IN 48 HOURS,
THE RISK FOR FLASH FLOODING WILL INCREASE.
FOR TUESDAY NIGHT INTO WEDNESDAY, THE FRONTAL BOUNDARY THAT HAS
SUSTAINED THESE MULTIPLE ROUNDS OF STORMS SHOULD BE SOUTH OF THE
FORECAST AREA, ALLOWING FOR ANY NEW DEVELOPMENT TO FAVOR AREAS TO
THE SOUTHWEST. THERE IS SOME POTENTIAL FOR THE BOUNDARY TO BE CLOSE
TO OUR SOUTHWEST COUNTIES AND SOME SCATTERED RAIN ACTIVITY WILL BE
POSSIBLE THROUGH WEDNESDAY BUT THE MAIN SEVERE AND HEAVY RAIN
THREATS SHOULD BE OUT OF THE AREA. IF THE FRONT DOES HAVE TROUBLE
CLEARING THE AREA WITH ALL OF THE UNCERTAINTY WITH THE PREVIOUS
ROUNDS OF STORMS, THEN THERE COULD BE MORE SEVERE WEATHER
POTENTIAL OR HEAVY RAIN/FLASH FLOODING POTENTIAL ON WEDNESDAY,
WHICH EXPLAINS WHY SOME PORTIONS OF NORTHERN OHIO REMAIN IN DAY
3 SPC SEVERE AND WPC EXCESSIVE RAINFALL MARGINAL RISKS.
KEY MESSAGE 2...
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION ON THURSDAY
FROM THE NORTHWEST. THIS WILL BRING DRY WEATHER AND LESS
HUMIDITY INTO THE REGION, GIVING SOME RELIEF FROM THE MORE MUGGY
WEATHER FROM EARLIER IN THE WEEK. THIS SYSTEM WILL MAINTAIN
OVER THE GREAT LAKES THROUGH FRIDAY, ALLOWING FOR TEMPERATURES
TO DROP BACK INTO THE 70S.
KEY MESSAGE 3...
A SUBTLE SHORTWAVE WILL MOVE THROUGH THE GREAT LAKES REGION
THIS WEEKEND AND ALLOW FOR THE UPPER LEVEL PATTERN TO RETURN TO
NORTHWEST FLOW. LIKE EARLIER IN THE WEEK, THIS NORTHWEST FLOW
PATTERN WILL BRING A FEW WEAK DISTURBANCES THROUGH THE AREA ON
SATURDAY AND SUNDAY, EACH WITH SOME SCATTERED SHOWER AND STORM
CHANCES. IT IS TOO EARLY TO TELL IF THERE WILL BE ANY SEVERE
WEATHER OR FLOODING HAZARDS AT THIS TIME. IF TEMPERATURES REMAIN
MUTED IN THE UPPER 70S, THEN CONVECTIVE ACTIVITY MAY BE
REDUCED.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE FIRST OF MANY COMPLEXES OF SHOWERS AND THUNDERSTORMS THAT
WILL IMPACT THE AREA IN THE COMING DAYS IS NOW EAST OF THE AREA,
SO EXPECT MAINLY DRY AND VFR CONDITIONS AT ALL TERMINALS THROUGH
10Z THIS MORNING OTHER THAN A FEW LINGERING SPOTTY SHOWERS. THE
NEXT COMPLEX CURRENTLY ORGANIZING OVER LAKE MICHIGAN SHOULD
MAINTAIN STRENGTH AND TRACK ACROSS THE REGION LATER THIS
MORNING. TIMING IS A ROUGH ESTIMATE AND COULD END UP BEING AN
HOUR FASTER IF A COLD POOL DEVELOPS AND ACCELERATES THE SYSTEM,
BUT ESTIMATE IT TO REACH KTOL AND KFDY AROUND 10Z, KMFD AND KCLE
AROUND 12Z, KCAK AND KYNG AROUND 13Z, AND KERI AROUND 15Z.
BROUGHT ALL SITES DOWN TO MVFR AS A STARTING POINT IN SHOWERS
AND THUNDERSTORMS, BUT IFR IS POSSIBLE IN THE BRIEFLY HEAVIER
RAIN AND GUSTY WINDS. A LULL IS EXPECTED BEHIND THIS COMPLEX FOR
LATE MORNING THROUGH THE AFTERNOON WITH VFR CONDITIONS, BUT THEN
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL START TO DEVELOP THIS
EVENING INTO TONIGHT. CONFIDENCE ON THE LOCATION OF THE ACTIVITY
THIS EVENING AND TONIGHT IS VERY LOW, BUT TRIED TO SHOW THE
WESTERN HALF OF OUR AREA AROUND KTOL, KFDY, AND KMFD HAVING
BETTER CHANCES FOR THUNDER THAN SITES FARTHER EAST.
LIGHT S TO SW WINDS EARLY THIS MORNING WILL INCREASE BY MID TO
LATE MORNING AND BECOME GUSTY THROUGH THE AFTERNOON. EXPECT SW
WINDS OF 10-15 KNOTS BY THIS AFTERNOON, GUSTING TO 20-25 KNOTS
AT TIMES. SW WINDS WILL DECREASE THIS EVENING.
OUTLOOK...PERIODS OF NON-VFR CONDITIONS ARE EXPECTED THROUGH
THURSDAY AS SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS MOVE
ACROSS THE AIRSPACE. SOME STORMS COULD BE STRONG TO SEVERE
DURING THIS TIMEFRAME.
MARINE
SW WINDS WILL INCREASE TO 15-20 KNOTS LATER THIS MORNING THROUGH
THE AFTERNOON BEHIND A WARM FRONT. THIS WILL BUILD WAVE HEIGHTS
TO OVER 4 FEET IN THE OPEN WATERS OF THE CENTRAL AND EASTERN
BASINS. AT THIS POINT, EXPECT THE BIGGEST WAVES AND STRONGEST
WINDS TO BE IN THE OPEN WATERS, SO DID NOT ISSUE A SMALL CRAFT
ADVISORY, BUT IT WILL BE VERY CLOSE. BOATERS SHOULD NONETHELESS
EXPECT CHOPPY CONDITIONS.
WINDS WILL BECOME LIGHT AND VARIABLE TONIGHT, AND EXPECT THAT TO
LARGELY BE THE CASE THROUGH WEDNESDAY AS A FRONTAL BOUNDARY
OSCILLATES JUST SOUTH OF THE LAKE. STRONGER WINDS AVERAGING A N
DIRECTION WILL THEN BEGIN LATE WEDNESDAY AND CONTINUE THROUGH
FRIDAY AS THE FRONT FINALLY PUSHES SOUTH AND CANADIAN HIGH
PRESSURE ATTEMPTS TO BUILD ACROSS THE GREAT LAKES.
OTHERWISE, MULTIPLE ROUNDS OF THUNDERSTORMS WILL IMPACT THE LAKE
TODAY THROUGH WEDNESDAY. ANY ORGANIZED STORMS THAT CROSS THE
LAKE COULD PRODUCE LOCALLY STRONG WINDS OVER 50 KNOTS AND HIGH
WAVES.
CLE WATCHES/WARNINGS/ADVISORIES
OH...NONE.
PA...NONE.
MARINE...NONE.
DISCUSSION...SEFCOVIC
AVIATION...GARUCKAS
MARINE...GARUCKAS
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