549
FXUS61 KCLE 091339
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
939 AM EDT SUN AUG 9 2020
SYNOPSIS
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL CONTINUE MOVING
SOUTHEAST TODAY. A WARM FRONT WILL LIFT NORTHEASTWARD ACROSS THE
REGION ON MONDAY. A COLD FRONT WILL CROSS THE AREA ON TUESDAY.
HIGH PRESSURE WILL RETURN TO THE REGION ON WEDNESDAY.
NEAR TERM /THROUGH MONDAY/
CURRENT FORECAST IS ON TRACK. ONLY MADE MINOR CHANGERS TO CLOUD
COVER AND HOURLY TEMPERATURES TO REFLECT CURRENT TRENDS.
PREVIOUS DISCUSSION...
SUNDAY WILL FEATURE THE LAST QUIET WEATHER DAY OF THIS STRETCH
WITH HIGH PRESSURE SLIDING SOUTHEAST OF THE AREA. SOUTHWEST FLOW
WILL RETURN TO THE REGION ON THE WEST SIDE OF THIS SYSTEM,
ALLOWING FOR TEMPERATURES AND MOISTURE TO INCREASE ACROSS THE
REGION. UPPER RIDGING OVER THE AREA WILL ALLOW FOR DRY
CONDITIONS, BUT THE INFLUX OF MOISTURE WILL ALLOW FOR SOME
DIURNAL CUMULUS TO BE THE MAIN PROBLEM OF THE DAY. HIGH
TEMPERATURES WILL BE SEVERAL DEGREES WARMER THAN SATURDAY AND
SOME LOCATIONS MAY SEE 90 DEGREES FOR THE FIRST TIME IN SEVERAL
WEEKS. OVERNIGHT LOWS WILL REMAIN WARM IN THE 60S WITH SOME
CLOUDS ENTERING THE REGION AND WARMER DAYTIME HIGHS.
A WARM FRONT WILL APPROACH THE AREA ON MONDAY AND WILL PROMOTE
WARM TEMPERATURES ONCE AGAIN WITH PERHAPS MORE WIDESPREAD LOWER
90S ACROSS THE REGION. THE MAIN QUESTION WITH THIS FRONT IS
PRECIPITATION POTENTIAL. THE SUPPORTING SHORTWAVE TROUGH APPEARS
TO HAVE SLOWED THROUGH THE GREAT LAKES REGION AND THEREFORE, THE
BEST TIMING OF RAIN HAS SHIFTED SLIGHTLY LATER IN THE DAY. HAVE
POPS INCREASING THROUGH THE AFTERNOON HOURS ON MONDAY, BUT THE
BEST RAIN CHANCES APPEAR TO BE BEYOND THE NEAR TERM FORECAST
PERIOD FOR MUCH OF THE FORECAST AREA. SOME INSTABILITY OVER THE
REGION WILL ALLOW FOR SOME THUNDER POTENTIAL AND HAVE THUNDER
MENTIONED FOR MONDAY AFTERNOON.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
BY THE BEGINNING OF THE SHORT TERM FORECAST PERIOD, AN UPPER LEVEL
RIDGE THAT PERSISTED OVER THE AREA DURING THE WEEKEND WILL BEGIN TO
BE REPLACED BY AN UPPER LEVEL LONGWAVE TROUGH, RESULTING IN UPPER
WESTERLY FLOW ACROSS THE AREA. MULTIPLE SHORTWAVE DISTURBANCES ARE
EXPECTED TO MOVE ALONG THE PERIPHERY OF THIS LONGWAVE TROUGH AND
IMPACT THE CWA THROUGHOUT THE WEEK. BEGINNING ON MONDAY NIGHT, A
FRONTAL SYSTEM APPROACHES THE AREA FROM THE WEST AS THE RIDGE EXITS
THE AREA TO THE EAST. AHEAD OF THE COOL FRONT MOVING ACROSS THE AREA
ON TUESDAY, WINDS WILL BE FROM THE SOUTHWEST DUE TO THE BACK EDGE OF
THE HIGH PRESSURE SYSTEM. THIS WILL ALLOW FOR AMPLE MOISTURE
ADVECTION INTO THE REGION FROM THE GULF OF MEXICO, RESULTING IN THE
RETURN OF HUMID CONDITIONS. THE COOL FRONT SHOULD MOVE THROUGH THE
AREA BY TUESDAY AFTERNOON/EVENING. SCATTERED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE MONDAY EVENING THROUGH TUESDAY EVENING
WITH THE APPROACH AND PASSAGE OF THE FRONT. CURRENT MODELS HAVE
LIMITED VERTICAL WINDS SHEAR ASSOCIATED WITH THIS SYSTEM, HOWEVER
MODERATE FORECAST INSTABILITY VALUES, A VERY MOIST ATMOSPHERE, AND
SOME MODELS SUGGESTING UPPER LEVEL SUPPORT WITH A SHORT WAVE TROUGH
MAY ALLOW FOR A FEW PULSE THUNDERSTORMS TO BECOME STRONG, WITH
STRONG WINDS BEING THE PRIMARY THREAT.
ANOTHER WEAK HIGH PRESSURE IS EXPECTED TO BUILD INTO THE AREA
TUESDAY NIGHT INTO WEDNESDAY. OPTED TO KEEP CHANCE OF SCATTER
SHOWERS AND THUNDERSTORMS IN THE FORECAST ON WEDNESDAY AS LINGERING
MOISTURE AND DIURNAL INSTABILITY CANNOT COMPLETELY RULE THEM OUT.
HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE IN THE LOW TO MID
80S, WITH HUMIDITY RETURNING ACROSS THE AREA. LOW TEMPERATURES
OVERNIGHT WILL DIP DOWN INTO THE MID 60S.
LONG TERM /THURSDAY THROUGH SATURDAY/
DURING THE LONG TERM PERIOD, THE LONG WAVE TROUGH WILL CONTINUE TO
SLOWLY PROGRESS EASTWARD AS EMBEDDED SHORTWAVE TROUGHS ALSO CONTINUE
TO PROPOGATE EASTWARD THROUGHOUT THE PERIOD. BEHIND THIS TROUGH, A
RIDGE OF HIGH PRESSURE BEGINS TO BUILD ACROSS THE EASTERN US,
HOWEVER A LOW PRESSURE BUILDING IN THE MISSISSIPPI VALLEY IS
EXPECTED TO UNDERCUT THIS RIDGE DURING THE LONG TERM FORECAST
PERIOD. OVER OUR AREA, IT IS FORECAST THAT A WEAK HIGH PRESSURE
REMAINS OVER THE AREA, HOWEVER MODELS BEGIN TO DIVERGE TOWARDS THE
END OF THE PERIOD WITH HANDLING THIS NEXT SYSTEM. KEPT CHANCE OF
POPS IN FOR THE MAJORITY OF THE FORECAST PERIOD DUE TO THE DIURNAL
CYCLE INTERACTING WITH THE LINGERING MOISTURE OVER THE AREA. HIGH
TEMPERATURES DURING THIS PERIOD WILL BE IN THE MID 80S WITH
OVERNIGHT LOWS NEAR THE MID TO UPPER 60S.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
HIGH PRESSURE CENTERED SOUTHEAST OF THE AIRSPACE WILL ALLOW FOR
VFR CONDITIONS TO CONTINUE THROUGH TAF PERIOD. SOME SPOTTY
CIRRUS HAS BEEN OVERHEAD THIS MORNING AND AS HIGH PRESSURE
CONTINUES MOVING SOUTHEAST, BETTER MOISTURE WILL ENTER THE
REGION AND DIURNAL CUMULUS SHOULD FORM OVER THE REGION THIS
AFTERNOON. ANY OF THESE LOWER CLOUDS SHOULD DISSIPATE LATE THIS
EVENING. SHOWERS AND THUNDERSTORMS TO THE WEST OF THE REGION
MAY ALLOW FOR SOME CIRRUS CLOUDS TO MOVE IN TONIGHT. WINDS WILL
BE GENERALLY SOUTHWESTERLY THROUGH THE PERIOD AS HIGH PRESSURE
MOVES TO THE SOUTHEAST.
OUTLOOK...NON-VFR POSSIBLE WITH AFTERNOON SHOWERS AND THUNDERSTORMS
MONDAY THROUGH WEDNESDAY.
MARINE
HIGH PRESSURE WILL CONTINUE TO PERSIST OVER LAKE ERIE FOR SUNDAY AND
PART OF MONDAY. WINDS TODAY WILL BE FROM THE SOUTHWEST AT 5 TO 10
KNOTS IN THE WESTERN BASIN AND 10 TO 15 KNOTS IN THE EASTERN BASIN.
BY SUNDAY NIGHT, WINDS WILL BECOME MORE SOUTHERLY AND WEAKEN TO 5 TO
10 KNOTS ACROSS THE ENTIRE LAKE AND PERSIST UNTIL MONDAY AFTERNOON
AS THE HIGH PRESSURE SHIFTS TOWARDS THE SOUTHERN APPALACHIANS. A
COLD FRONT SHOULD MOVE ACROSS LAKE ERIE TUESDAY AFTERNOON, CAUSING
WINDS TO BECOME MORE WESTERLY. AHEAD OF AND WITH THE PASSAGE OF THIS
FRONT, SHOWERS AND THUNDERSTORMS ARE POSSIBLE, WHICH HAVE THE
POSSIBILITY OF PRODUCING LOCALLY STRONGER WINDS AND HIGHER WAVES.
HIGH PRESSURE IS EXPECTED TO BUILD BACK IN ACROSS THE AREA ON
WEDNESDAY INTO THURSDAY, ALLOWING WINDS TO BECOME NORTHEASTERLY AT 5
TO 15 KNOTS. THROUGHOUT THE ENTIRE FORECAST PERIOD, WAVES WILL
LIKELY BE BETWEEN 1 TO 3 FEET. NO HEADLINES ARE EXPECTED AT THIS
TIME.
CLE WATCHES/WARNINGS/ADVISORIES
OH...NONE.
PA...NONE.
MARINE...NONE.
SYNOPSIS...SEFCOVIC
NEAR TERM...MM/SEFCOVIC
SHORT TERM...CAMPBELL
LONG TERM...CAMPBELL
AVIATION...SEFCOVIC
MARINE...CAMPBELL
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