602  
FXUS61 KCLE 191011  
AFDCLE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CLEVELAND OH  
611 AM EDT FRI AUG 19 2022  
   
..12Z TAF AVIATION AND NEAR FORECAST UPDATE
 
 
   
SYNOPSIS
 
 
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE EAST OF THE REGION  
TONIGHT. LOW PRESSURE WILL IMPACT THE AREA THIS WEEKEND INTO  
EARLY NEXT WEEK. MOST OF THE AREA WILL SEE DRY WEATHER THROUGH  
TONIGHT, BUT EXPECT PERIODIC SHOWERS AND THUNDERSTORMS THIS  
WEEKEND INTO EARLY NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH SATURDAY/
 
 
600 AM UPDATE...  
NO CHANGES WERE NEEDED WITH THIS EARLY MORNING UPDATE.  
 
PREVIOUS DISCUSSION...  
THE CENTER OF HIGH PRESSURE IS CURRENTLY LOCATED NEAR WESTERN  
PENNSYLVANIA THIS MORNING. MOST OF THE WEATHER OBSERVATIONS ARE  
INDICATING A LIGHT SOUTHERLY WINDS AROUND 5 MPH OR SO HAS  
RETURNED TO THE AREA. WE WILL ALSO BEGIN TO SEE OUR SURFACE  
MOISTURE AND DEWPOINTS CLIMB TODAY WITH THOSE LIGHT SOUTHERLY  
WINDS. UPPER LEVEL HEIGHTS WILL RISE SLIGHTLY TODAY GIVING WAY  
TO A MOSTLY SUNNY AND NEARLY SEASONABLE LATE AUGUST DAY. HIGH  
TEMPERATURES WILL CLIMB INTO THE LOWER AND MIDDLE 80S AREAWIDE.  
A FEW OF THE FORECAST MODELS SHOW AN OUTSIDE CHANCE FOR A COUPLE  
ISOLATED SHOWERS OR THUNDERSTORMS POPPING UP ACROSS WESTERN  
OHIO THIS AFTERNOON. AT THIS TIME, WE HAVE LEFT OUT ANY POPS FOR  
TODAY AND WE SHOULD REMAIN MOSTLY DRY TODAY INTO TONIGHT.  
 
THE NEXT WEATHER SYSTEM TO IMPACT OUR REGION WITH SCATTERED  
SHOWERS AND THUNDERSTORMS WILL BE AN UPPER LEVEL LOW MOVING  
DOWN FROM THE UPPER MIDWEST REGION ACROSS THE LOWER GREAT LAKES  
REGION ON SATURDAY. WE WILL CARRY A SLIGHT CHANCE OF POP THROUGH  
THE MORNING HOURS OF SATURDAY. AS THE LOW PRESSURE SYSTEM MOVE  
CLOSER TOWARDS CHICAGO BY 00Z SUNDAY, WE WILL SEE OUR RAIN  
CHANCES AND POPS INCREASE LATE SATURDAY AFTERNOON INTO SATURDAY  
EVENING. THE THERMODYNAMICS FOR STRONG TO SEVERE CONVECTION WILL  
BE VERY LIMITED. WEST-SOUTHWESTERLY SHEAR VALUES WILL BE IN THE  
MARGINAL RANGE OF 25-35 KNOTS BY LATE SATURDAY. MIXED LAYER  
CAPE VALUES WILL BE MODEST AT 1000-2000 J/KG. THE OVERALL  
EXPECTATIONS WILL BE FOR MULTICELLS CAPABLE OF PRODUCING  
ISOLATED DAMAGING WIND GUSTS AS THE MAIN THREAT WITH THE  
STRONGEST ORGANIZED CONVECTION. MID LEVEL LAPSE RATES ARE LACK  
LUSTER. SMALL TO ISOLATED MARGINALLY SEVERE HAIL COULD BE  
POSSIBLE BUT NOT LIKELY. OTHERWISE, JUST GENERAL SCATTERED  
THUNDERSTORMS ARE EXPECTED WITH LIGHTNING, GUSTY WINDS, AND  
BRIEF HEAVY DOWNPOURS. SPC HAS MOST OF NORTHERN OHIO IN A DAY 2  
MARGINAL OUTLOOK FOR SEVERE THUNDERSTORMS LATE ON SATURDAY.  
 

 
   
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/
 
 
UNSETTLED WEATHER WILL BE THE STORY FOR THE LATTER HALF OF THE  
WEEKEND THROUGH EARLY NEXT WEEK AS A CLOSED MID/UPPER LOW OVER  
THE WESTERN GREAT LAKES SATURDAY NIGHT OPENS UP INTO A TROUGH BY  
SUNDAY WHILE SLOWLY PROGRESSING EASTWARD THROUGH THE LOWER  
GREAT LAKES AND OHIO VALLEY SUNDAY NIGHT AND MONDAY. THE AXIS OF  
THE TROUGH SHOULD REACH THE EASTERN GREAT LAKES BY MONDAY  
NIGHT. AS THIS ALL HAPPENS, A WEAK SURFACE LOW ASSOCIATED WITH  
THE MID/UPPER TROUGH WILL SLOWLY TRANSLATE FROM NEAR CHICAGO  
SATURDAY NIGHT INTO THE VICINITY OF UPSTATE NEW YORK BY MONDAY  
AND MONDAY NIGHT DRAGGING AN ATTENDANT COLD FRONT EAST/SOUTHEAST  
THROUGH THE LOWER GREAT LAKES AND OHIO VALLEY. GUIDANCE IS IN  
PRETTY GOOD AGREEMENT THAT THIS FRONT WILL GRADUALLY CROSS  
NORTHERN OHIO AND NW PA FROM MONDAY THROUGH EARLY TUESDAY.  
 
AS THE CLOSED LOW/TROUGH APPROACHES FROM THE WESTERN GREAT LAKES  
SATURDAY NIGHT AND SUNDAY, CONTINUED WARM/MOIST ADVECTION BEHIND A  
WARM FRONT THAT LIFTS OVER OR JUST NORTH OF LAKE ERIE WILL PUMP  
WARMER, MORE HUMID AIR INTO THE REGION, BUT ONLY SEASONABLY HIGH  
VALUES WITH DEW POINTS IN THE MID/UPPER 60S. THIS COMBINED WITH WEAK  
ASCENT FROM THE LEFT EXIT OF A 60-70 KNOT H3 JET STREAK AND UPPER  
DIFFLUENCE WILL KEEP FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS  
GOING SATURDAY NIGHT, WITH COVERAGE THEN BECOMING MAXIMIZED WITH  
DAYTIME HEATING BY SUNDAY AFTERNOON. A FEW STRONG THUNDERSTORMS ARE  
POSSIBLE EARLY SATURDAY NIGHT GIVEN MODERATE INSTABILITY (MLCAPE  
1000-2000 J/KG) AND MODEST DEEP LAYER WEST-SOUTHWESTERLY SHEAR OF 25-  
35 KNOTS, BUT THE OVERALL WEAK FORCING AND MARGINAL THERMODYNAMICS  
AND KINEMATICS WILL KEEP ANY SEVERE THREAT LOCALIZED WITH WET  
MICROBURSTS BEING THE MAIN IMPACT FROM LOOSELY ORGANIZED CLUSTERS.  
ABUNDANT CLOUD COVER COULD FURTHER LOWER INSTABILITY WHICH WOULD  
MAKE THE THREAT EVEN LESS, SO THIS IS DEFINITELY A LOW CONFIDENCE,  
MARGINAL SET UP. FOR SUNDAY, I SUSPECT THAT COVERAGE OF  
SHOWERS/STORMS WILL BE SO WIDESPREAD THAT THERE WILL NOT BE MUCH  
INSTABILITY GIVEN THE LOW/TROUGH PASSING ALMOST DIRECTLY OVERHEAD.  
ISOLATED WET MICROBURSTS ARE POSSIBLE, BUT THE MAIN IMPACT WILL  
PROBABLY BE LOCALLY HEAVY RAINFALL GIVEN THE FACT THAT STORM MOTION  
WILL BE SLOW DUE TO WEAK MID-LEVEL FLOW OF 20-30 KNOTS AND PWATS UP  
TO 1.50 INCHES (SEASONABLE VALUES, BUT STILL SUPPORTS GOOD  
DOWNPOURS). AREAS THAT SEE HEAVY RAIN SATURDAY AND SATURDAY NIGHT  
WILL HAVE THE GREATEST RISK OF LOCALIZED FLOODING SUNDAY. AS THE  
SURFACE AND UPPER SYSTEM GRADUALLY MOVE FARTHER EAST SUNDAY NIGHT,  
CONVECTIVE COVERAGE WILL DECREASE AIDED BY THE LOSS OF DAYTIME  
HEATING, BUT EXPECT LIKELY POPS TO RETURN MONDAY AFTERNOON AS THE  
ATTENDANT COLD FRONT STARTS TO WRAP IN FROM THE WEST, WITH ITS  
INCREASED LOW-LEVEL CONVERGENCE WORKING WITH THE MOIST AIRMASS AND  
AT LEAST WEAK INSTABILITY. THIS WILL LEAD TO FAIRLY WIDESPREAD  
SHOWERS/STORMS AGAIN MONDAY, AGAIN WITH THE THREAT OF LOCALIZED  
FLOODING BEFORE COVERAGE DECREASES MONDAY NIGHT.  
 
HIGHS SUNDAY AND MONDAY WILL BE NEAR TO SLIGHTLY BELOW NORMAL IN THE  
UPPER 70S/LOW 80S BUT MUGGY. LOWS SATURDAY NIGHT WILL BE IN THE  
MID/UPPER 60S COOLING SLIGHTLY INTO THE LOW/MID 60S SUNDAY NIGHT AND  
MONDAY NIGHT.  
 

 
   
LONG TERM /TUESDAY THROUGH THURSDAY/
 
 
LONGWAVE MID/UPPER TROUGHING WILL LINGER ACROSS THE EASTERN CONUS IN  
THE WAKE OF THE SYSTEM THROUGH MIDWEEK KEEPING TEMPS NEAR TO  
SLIGHTLY BELOW NORMAL. WEAK SURFACE HIGH PRESSURE TRIES TO BUILD  
EAST FROM THE UPPER MIDWEST TUESDAY AND WEDNESDAY, BUT CONTINUED MID  
LEVEL CYCLONIC FLOW AND SOME LINGERING LOW-LEVEL MOISTURE COMBINED  
WITH PERIODIC WEAK SHORTWAVES DROPPING THROUGH THE TROUGH WILL  
CONTINUE TO DEVELOP ISOLATED SHOWERS/STORMS EACH AFTERNOON. GUIDANCE  
DIFFERS ON TIMING OF THE SHORTWAVES, SO KEPT POPS CONFINED TO THE  
DIURNAL MAXIMUMS IN THE AFTERNOONS WITH DRY CONDITIONS THE REST OF  
THE TIME. THERE IS SOME CONSENSUS THAT A STRONGER SHORTWAVE AND  
ASSOCIATED COLD FRONT MAY APPROACH THURSDAY.  
 
HIGHS GENERALLY IN THE UPPER 70S/LOW 80S TUESDAY WILL MODIFY TO MORE  
SOLID LOW 80S WEDNESDAY AND THURSDAY.  
 

 
   
AVIATION /12Z FRIDAY THROUGH TUESDAY/
 
 
VFR CONDITIONS WILL PREVAIL THROUGH THIS TAF PERIOD FOR ALL OF  
NORTHERN OHIO AND NORTHWEST PA. SKIES WILL BE MOSTLY CLEAR TO  
FAIR WEATHER SKIES DURING THE TIME PERIOD. WINDS WILL BE LIGHT  
AND VARIABLE BECOMING SOUTHERLY AROUND 5 KNOTS LATER THIS  
MORNING THROUGH THE END OF THE TIME FRAME.  
 
OUTLOOK...NON-VFR POSSIBLE WITH SCATTERED RAIN SHOWERS AND  
THUNDERSTORMS SATURDAY THROUGH TUESDAY, WITH THE BEST CHANCE  
SATURDAY AFTERNOON THROUGH MONDAY.  
 

 
   
MARINE
 
 
QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE PERIOD EXCEPT FOR  
PERIODIC THUNDERSTORMS SATURDAY THROUGH MONDAY THAT WILL CREATE  
LOCALLY HIGHER WINDS AND WAVES, ALONG WITH LIGHTNING. THE GREATEST  
POTENTIAL FOR THUNDERSTORMS WILL BE IN THE AFTERNOONS AND EVENINGS.  
 
LIGHT SSW WINDS OF 5-10 KNOTS TODAY WILL BECOME SSE TONIGHT THROUGH  
SATURDAY NIGHT, THEN MAINLY S ON SUNDAY. WINDS BEGIN TO VEER W  
SUNDAY NIGHT AND NW MONDAY WITH SPEEDS STAYING 5-10 KNOTS AS A COLD  
FRONT SLOWLY CROSSES TIED TO LOW PRESSURE PASSING OVERHEAD. N TO NW  
WINDS INCREASE A BIT TO 10-15 KNOTS TUESDAY ALLOWING WAVES TO BUILD  
TO 1 TO 3 FEET, AND THOSE WILL BE THE BIGGEST WAVES OF THE  
PERIOD.  
 

 
   
CLE WATCHES/WARNINGS/ADVISORIES
 
 
OH...NONE.  
PA...NONE.  
MARINE...NONE.  
 

 
 

 
SYNOPSIS...GRIFFIN  
NEAR TERM...GRIFFIN  
SHORT TERM...GARUCKAS  
LONG TERM...GARUCKAS  
AVIATION...GRIFFIN  
MARINE...GARUCKAS  
 
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