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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