915
FXUS61 KCLE 042012
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
412 PM EDT SUN MAY 4 2025
SYNOPSIS
LOW PRESSURE WILL WEAKEN THROUGH TUESDAY AS IT SLOWLY DRIFTS
NORTHEAST THROUGH REGION. HIGH PRESSURE WILL BRIEFLY BUILD INTO THE
REGION WEDNESDAY WITH A COLD FRONT MOVING ACROSS THE AREA WEDNESDAY
NIGHT. HIGH PRESSURE WILL STRENGTHEN AGAIN TO END THE WEEK.
NEAR TERM /THROUGH MONDAY NIGHT/
AN UPPER LEVEL CLOSED LOW CAN BE SEEN ON WATER VAPOR SPINNING OVER
THE OHIO VALLEY. OCCASIONAL SHOWERS, LARGELY DIURNALLY DRIVEN,
WILL CONTINUE TO ROTATE AROUND THIS LOW THROUGH THE NEAR TERM
FORECAST. FOR TONIGHT, WE HAVE A STEADY BAND OF RAIN ACROSS
NORTHEAST OHIO WHERE A THETA-E RIDGE AND DEEP MOISTURE
CONVERGENCE IS FOCUSED. THE SURFACE TROUGH ALSO EXTENDS NORTH
ACROSS EASTERN OHIO WITH WEAK CONVERGENCE FOCUSED ALONG THIS
BOUNDARY. A MID-LEVEL DRY SLOT HAS WRAPPED NORTH AROUND THE
UPPER LOW TODAY WHICH HAS ALLOWED FOR SOME BREAKS TO DEVELOP IN
THE CLOUDS, MAINLY SOUTH OF ROUTE 30, AND FOR WEAK INSTABILITY
OF A COUPLE HUNDRED JOULES OF ML CAPE FROM CENTRAL OHIO
TOWARDS YOUNGSTOWN. SOME THUNDERSTORMS HAVE DEVELOPED ACROSS
SOUTHERN OHIO AS THE ATMOSPHERE COOLS ALOFT. THIS UPPER LEVEL
COLD POOL IS FORECAST TO PIVOT NORTH THIS EVENING WITH A CHANCE
OF THUNDERSTORMS IN THE FORECAST, ESPECIALLY ACROSS NORTH
CENTRAL AND NORTHEAST OHIO. OUR SOUTHEASTERN TIER OF COUNTIES IS
JUST CLIPPED BY A MARGINAL RISK FOR SEVERE THUNDERSTORMS FOR
THIS EVENING THROUGH ABOUT 9 PM. INSTABILITY WILL BE A LIMITING
FACTOR AND ALREADY STARTING TO WANE BY THEN. IF ANY GOOD
UPDRAFTS CAN GET GOING THEN SMALL TO MEDIUM SIZE HAIL AND AN
ISOLATED WIND GUST TO 50 MPH CAN NOT BE RULED OUT GIVEN
EFFECTIVE SHEER VALUES INCREASING TO AROUND 40 KNOTS. IN
ADDITION, DEEP LAYER SHEER IN THE ATMOSPHERE COULD SUPPORT A
ROTATING STORM OR TWO WHERE SURFACE BOUNDARIES ARE FOCUSED.
HIGHER CONFIDENCE IS IN A GOOD SWATH OF RAIN ACROSS NORTHEAST
OHIO WHERE RAIN SHOULD BE FAIRLY PERSISTENT OVER THE NEXT
SEVERAL HOURS. MODEL SOUNDINGS SHOW THE COLUMN IS NEARLY
SATURATED UP TO THE FREEZING LEVEL AND EXPECTING AROUND AN INCH
OF RAIN. SOME HIGH RESOLUTION MODELS ARE SUGGESTING POCKETS OF 2
INCHES OR MORE COULD ALSO OCCUR IN THIS AREA AND WILL NEED TO
KEEP AN EYE ON RAINFALL AMOUNTS WITH SOME LOW END THREAT OF
FLOODING. THIS COULD ALSO LEAD TO ADDITIONAL RISES ON EAGLE
CREEK PHALANX WHERE MINOR FLOODING IS ALREADY ONGOING.
SHOWERS WILL TEND TO DIMINISH OVERNIGHT AS WE LOSE DIURNAL HEATING.
MODELS HAVE SUGGESTED THAT BREAKS IN THE STRATUS DECK COULD ALLOW
FOR THE BOUNDARY LAYER TO COOL AND AREAS OF FOG TO DEVELOP LATE
TONIGHT. HAVE ADDED PATCHY/AREAS OF FOG TO THE FORECAST WITH
GENERALLY LIGHT WINDS AND LOW PRESSURE IN THE REGION.
THE UPPER LOW CONTINUES TO INFLUENCE THE REGION ON MONDAY. WE WILL
START THE DAY WITH LOWER COVERAGE OF SHOWERS THAN THE PAST COUPLE
DAYS WITH THE DRY-SLOT OVERHEAD. TEMPERATURES WILL RECOVER INTO THE
MID 60S TO NEAR 70 DEGREES ALLOWING FOR A LITTLE BETTER INSTABILITY
ON MONDAY AFTERNOON IN THE 500-900 J/KG RANGE. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS CENTRAL OHIO AND
MOVE NORTH THROUGH THE AFTERNOON AS A PLUME OF DEEPER MOISTURE
AND UPPER LEVEL COLD POOL ROTATE NORTH. AREAS GENERALLY EAST OF
I-77 ARE IN A MARGINAL RISK FOR SEVERE STORMS AGAIN WHICH LOOKS
A LITTLE BETTER THAN THE SEVERE RISK FOR THIS EVENING.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
ALOFT, A LOW SHOULD WOBBLE ENE'WARD FROM MID OH TO NEAR CENTRAL NY
BETWEEN DAYBREAK TUESDAY AND DAYBREAK WEDNESDAY. AT THE SURFACE, THE
ATTENDANT LOW SHOULD DEVELOP ENE'WARD FROM NEAR SOUTHEASTERN LOWER
MI TO NEAR THE UPPER SAINT LAWRENCE RIVER VALLEY AS THE ASSOCIATED
TROUGH LINGERS OVER THE LAKE ERIE REGION AND UPPER OH VALLEY. MOIST
ISENTROPIC ASCENT ASSOCIATED WITH THE LOW PRESSURE SYSTEM'S WARM
CONVEYOR BELT WILL GENERATE ABUNDANT CLOUD COVER OVER OUR REGION.
GIVEN THE SLOW-MOVING NATURE OF THE LOW PRESSURE CENTER AT THE
SURFACE AND ALOFT EARLY THIS WEEK, THE LOW'S CYCLONIC CIRCULATION IS
STILL EXPECTED TO DEFORM THE AIR TEMPERATURE FIELD AT THE SURFACE
AND ALOFT (E.G. AT 850 MB) SIGNIFICANTLY AND ALLOW A SLIGHTLY COOLER
AIR MASS TO OVERSPREAD OUR AREA FROM THE WEST AND SOUTH ON TUESDAY.
DESPITE PEEKS OF SUNSHINE, TUESDAY'S LATE AFTERNOON HIGHS ARE
EXPECTED TO REACH THE LOWER TO MID 60'S. BY TUESDAY NIGHT, THE LOW
PRESSURE SYSTEM'S CYCLONIC CIRCULATION AND CONTINUED SIGNIFICANT
DEFORMATION OF THE AIR TEMPERATURE FIELD AT THE SURFACE AND ALOFT
WILL ALLOW SLIGHTLY WARMER AIR TO OVERSPREAD OUR CWA FROM THE NORTH
AND WEST. THIS WEAK LOW-LEVEL WAA AND ABUNDANT CLOUD COVER WILL
CONTRIBUTE TO LIMITED NOCTURNAL COOLING AND SHOULD ALLOW OVERNIGHT
LOWS TO REACH THE UPPER 40'S TO MID 50'S AROUND DAYBREAK WEDNESDAY
MORNING.
PERIODIC RAIN SHOWERS ARE EXPECTED TUESDAY THROUGH TUESDAY NIGHT DUE
TO THE FOLLOWING: MOIST ISENTROPIC ASCENT ASSOCIATED WITH THE
AFOREMENTIONED WARM CONVEYOR BELT; LOW-LEVEL CONVERGENCE/MOIST
ASCENT ASSOCIATED WITH THE LOW'S CYCLONIC CIRCULATION. ISOLATED
THUNDERSTORMS ARE POSSIBLE LATE TUESDAY MORNING THROUGH EARLY
EVENING DUE TO WEAK DIURNAL DESTABILIZATION OF A RELATIVELY-MOIST
BOUNDARY LAYER AMIDST THE AFOREMENTIONED LOW-LEVEL CONVERGENCE.
NOTE: BY OVERNIGHT TUESDAY NIGHT, ANY LINGERING RAIN SHOWERS
ASSOCIATED WITH THE WARM CONVEYOR BELT SHOULD BE CONFINED TO AREAS
EAST OF ROUGHLY I-71 IN OUR CWA GIVEN THE PROJECTED TRACK OF THE LOW
AT THE SURFACE AND ALOFT.
ON WEDNESDAY THROUGH WEDNESDAY NIGHT, THE AFOREMENTIONED LOW ALOFT
SHOULD WOBBLE ENE'WARD FROM NEAR CENTRAL NY TO NEAR THE CANADIAN
MARITIMES AND BECOME VERTICALLY-STACKED WITH THE AFOREMENTIONED
SURFACE LOW ONCE AGAIN AS THE SURFACE LOW MOVES GENERALLY E'WARD
FROM THE UPPER SAINT LAWRENCE RIVER VALLEY. LINGERING ISOLATED RAIN
SHOWERS OVER NORTHEASTERN PORTIONS OF OUR CWA, ASSOCIATED WITH THIS
LOW PRESSURE SYSTEM'S WARM CONVEYOR BELT, SHOULD EXIT GENERALLY
E'WARD BY MIDDAY. OTHERWISE PRIMARILY CYCLONIC NW'ERLY FLOW ALOFT IS
EXPECTED TO IMPACT OUR REGION AS A SHORTWAVE DISTURBANCE APPROACHES
FROM NORTHERN ON AND EVENTUALLY THE SOUTHWESTERN AND CENTRAL GREAT
LAKES DURING THE DAYBREAK WEDNESDAY THROUGH DAYBREAK THURSDAY TIME
FRAME. AT THE SURFACE, NET TROUGHING LINGERS IN OUR CWA AND A COLD
FRONT IS EXPECTED TO SWEEP SE'WARD THROUGH OUR REGION ON WEDNESDAY.
LOW-LEVEL CONVERGENCE AND MOIST ASCENT ALONG THE COLD FRONT, AND
MOIST ISENTROPIC ASCENT ALOFT, AHEAD OF THE SHORTWAVE TROUGH AXIS,
SHOULD TRIGGER ISOLATED TO SCATTERED RAIN SHOWERS. INTERVALS OF
SUNSHINE AND WEAK LOW-LEVEL WAA AHEAD OF THE COLD FRONT SHOULD ALLOW
DAYTIME HIGHS TO REACH THE 60'S TO LOWER 70'S ON WEDNESDAY. WEAK LOW-
LEVEL CAA BEHIND THE COLD FRONT SHOULD CONTRIBUTE TO LOWS REACHING
THE MID 40'S TO LOWER 50'S AROUND DAYBREAK THURSDAY.
LONG TERM /THURSDAY THROUGH SUNDAY/
ON THURSDAY, NW'ERLY FLOW ALOFT PERSISTS OVER OUR REGION. THE
AFOREMENTIONED SHORTWAVE DISTURBANCE'S AXIS SHOULD SWEEP SE'WARD
THROUGH OUR REGION DURING THE MORNING THROUGH EARLY AFTERNOON HOURS.
ISOLATED TO SCATTERED RAIN SHOWERS ARE POSSIBLE THROUGH EARLY
AFTERNOON DUE TO MOIST ISENTROPIC ASCENT ALOFT, AHEAD OF THE
SHORTWAVE TROUGH'S AXIS, AND LOW-LEVEL CONVERGENCE/MOIST ASCENT
ALONG A SURFACE TROUGH AXIS PRECEDING THE TROUGH AXIS ALOFT. LATER
ON THURSDAY THROUGH THURSDAY NIGHT, STABILIZING SUBSIDENCE IS
EXPECTED TO PROMOTE FAIR WEATHER IN OUR CWA AS A HIGH PRESSURE RIDGE
AT THE SURFACE AND ALOFT BEGINS TO BUILD FROM THE WESTERN GREAT
LAKES AND VICINITY. CLEARING SKY AND CONTINUED LOW-LEVEL CAA ARE
EXPECTED TO CONTRIBUTE TO HIGHS REACHING THE MID 50'S TO MID 60'S ON
THURSDAY AND OVERNIGHT LOWS REACHING MAINLY THE UPPER 30'S TO UPPER
40'S AROUND DAYBREAK FRIDAY.
CURRENT ODDS FAVOR FAIR WEATHER THIS FRIDAY THROUGH SUNDAY AS THE
AFOREMENTIONED RIDGE AT THE SURFACE AND ALOFT SHOULD CONTINUE TO
BUILD GENERALLY FROM THE WEST AND AFFECT OUR REGION. WEAK LOW-LEVEL
CAA WILL EVENTUALLY GIVE WAY TO WEAK LOW-LEVEL WAA ON THE SYNOPTIC-
SCALE AS THE SURFACE RIDGE AXIS EVENTUALLY MOVES E'WARD ACROSS OUR
REGION. ACCORDINGLY, LATE AFTERNOON HIGHS IN THE 60'S ON FRIDAY
SHOULD BE FOLLOWED BY LATE AFTERNOON HIGHS IN THE MID 60'S TO MID
70'S ON SATURDAY AND SUNDAY, RESPECTIVELY. SUFFICIENT DAYTIME
HEATING OF SURFACE AIR OVER LAND SURROUNDING RELATIVELY-COLD LAKE
ERIE AND A FAIRLY-WEAK SYNOPTIC MSLP GRADIENT MAY PERMIT LAKE BREEZE
DEVELOPMENT DURING THE LATE MORNING THROUGH EARLY EVENING HOURS OF
SATURDAY AND SUNDAY. LOWS MAINLY IN THE UPPER 30'S TO UPPER 40'S
AROUND DAYBREAK SATURDAY SHOULD BE FOLLOWED BY LOWS IN THE MID 40'S
TO MID 50'S AROUND DAYBREAK SUNDAY.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
MUCH OF THE AREA IS EXPERIENCING A BREAK IN THE RAIN THIS
AFTERNOON AND EVEN A FEW BREAKS IN THE CLOUDS HAVE DEVELOPED
FORM CENTRAL OHIO TOWARDS CANTON. THE EXCEPTION TO THIS IS
ACROSS NORTHEAST OHIO WHERE A SWATH OF RAIN HAS FILLED IN OVER
THE LAST HOUR. THIS AREA OF RAIN ALIGNS WITH LOW LEVEL
CONVERGENCE AHEAD OF BROAD SURFACE LOW PRESSURE THAT IS
ROTATING NORTH THIS AFTERNOON. THERE IS A PRETTY GOOD SIGNAL IN
THE HIGH RESOLUTION MODELS THAT THIS RAIN WILL PERSIST FOR
SEVERAL HOURS AT YNG AND POSSIBLY EXTEND TO CLE/ERI/CAK THROUGH
THIS EVENING. IFR CONDITIONS ARE POSSIBLE IN RAIN. ELSEWHERE IN
THE NORTH WE CAN ALSO EXPECT IFR CEILINGS WITHOUT THE RAIN.
POTENTIAL FOR THUNDERSTORMS IS LOW BUT DOES EXIST. HAVE REMOVED
THE MENTION OF THUNDERSTORMS FROM MOST TERMINALS WITH THE MOST
LIKELY SITES AS CAK/YNG INTO THIS EVENING.
THE RAIN WILL MOSTLY TAPER OFF TONIGHT WITH BREAKS IN THE
CLOUDS FORECAST TO DEVELOP. THIS SEEMS LIKE A GOOD OPPORTUNITY
FOR FOG TO EXPAND ACROSS THE AREA WITH AMPLE MOISTURE REMAINING
IN THE LOW LEVELS AND WEAK FLOW WITH BROAD SURFACE LOW PRESSURE
IN THE REGION. UNCLEAR YET IF WIDESPREAD DENSE FOG WILL DEVELOP
BUT ADDED A WINDOW OF AT LEAST HALF MILE FOG BETWEEN 08-12Z WITH
POTENTIAL FOR ONE QUARTER MILE OR LESS. IMPROVEMENT IS EXPECTED
TO OCCUR QUICKLY BETWEEN 12-15Z MONDAY.
WITH LOW PRESSURE OVERHEAD, WINDS RANGE FROM NORTHEASTERLY ALONG
THE LAKESHORE TO SOUTHERLY AT MFD/CAK. SITES NEAR THE LAKE MAY
HAVE OCCASIONAL GUSTS TO AROUND 20 KNOTS.
OUTLOOK...PERIODIC SHOWERS AND THUNDERSTORMS WITH NON-VFR ARE
EXPECTED MONDAY AND TUESDAY.
MARINE
SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 4 AM EDT MONDAY FOR
NEARSHORE U.S. WATERS FROM MAUMEE BAY TO RIPLEY. A TROUGH LINGERS
OVER LAKE ERIE FOR THE TIME BEING. THE PARENT LOW SHOULD WEAKEN
GRADUALLY AT IT MEANDERS NEAR THE MID OH VALLEY THROUGH MONDAY.
PRIMARILY NE'ERLY TO E'ERLY WINDS AROUND 20 TO 30 KNOTS THROUGH THIS
EARLY EVENING EASE GRADUALLY TO 5 TO 15 KNOTS BY DAYBREAK MONDAY.
PRIMARILY NE'ERLY TO E'ERLY WINDS AROUND 5 TO 15 KNOTS THEN PERSIST
THROUGH SUNSET MONDAY EVENING. WAVES AS LARGE AS 5 TO 10 FEET
THROUGH THIS EARLY EVENING SHOULD SUBSIDE GRADUALLY TO 3 FEET OR
LESS IN U.S. WATERS BY DAYBREAK MONDAY.
THE WEAKENING LOW SHOULD WOBBLE N'WARD FROM THE MID OH VALLEY TO
SOUTHEASTERN LOWER MI ON MONDAY NIGHT THROUGH TUESDAY. THIS WILL
ALLOW MAINLY NE'ERLY TO E'ERLY WINDS AROUND 5 TO 15 KNOTS TO VEER
GRADUALLY TO SW'ERLY AS WAVES REMAIN 3 FEET OR LESS. THE LOW SHOULD
THEN TRACK ENE'WARD FROM SOUTHEASTERN LOWER MI TO NEAR SOUTHERN
QUEBEC TUESDAY NIGHT THROUGH WEDNESDAY AND ALLOW A COLD FRONT TO
SWEEP SE'WARD ACROSS LAKE ERIE ON WEDNESDAY. THE COLD FRONT PASSAGE
WILL CAUSE SW'ERLY WINDS AROUND 5 TO 15 KNOTS TO VEER TO N'ERLY AND
WAVES SHOULD REMAIN 3 FEET OR LESS. HOWEVER, OCCASIONAL 4 FOOTERS
ARE POSSIBLE BEHIND THE COLD FRONT. FOLLOWING THE COLD FRONT, A
RIDGE SHOULD BUILD FROM THE WESTERN GREAT LAKES AND VICINITY THROUGH
FRIDAY. ACCORDINGLY, N'ERLY TO NE'ERLY WINDS AROUND 5 TO 15 KNOTS
AND WAVES OF 3 FEET OR LESS ARE EXPECTED. OCCASIONAL 4 FOOTERS ARE
POSSIBLE.
CLE WATCHES/WARNINGS/ADVISORIES
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ142>149.
SYNOPSIS...10
NEAR TERM...10
SHORT TERM...JASZKA
LONG TERM...JASZKA
AVIATION...10
MARINE...JASZKA
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