767
FXUS61 KCLE 211029
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
629 AM EDT MON OCT 21 2019
SYNOPSIS
A SURFACE LOW TRACKS NORTHEASTWARD FROM THE UPPER MIDWEST TO WESTERN
LAKE SUPERIOR BY TUESDAY MORNING, THEN NORTH-NORTHEASTWARD TO
NORTHERN ONTARIO THROUGH TUESDAY EVENING. A WARM FRONT ASSOCIATED
WITH THIS LOW PRESSURE SYSTEM WILL MOVE NORTHEASTWARD OVER OUR
REGION THIS EVENING THROUGH THE PREDAWN HOURS OF TUESDAY, WHILE
A COLD FRONT SWEEPS EAST ACROSS THE LOCAL AREA LATE THIS
EVENING THROUGH TUESDAY MORNING. TROUGHING PERSISTS OVER OUR
AREA THE REST OF TUESDAY AND WEDNESDAY.
NEAR TERM /THROUGH TUESDAY/
OUR NEAR-TERM FORECAST REMAINS VALID. NO UPDATES NECESSARY AT
THIS TIME.
PREVIOUS DISCUSSION...FLOW ALOFT BECOMES PROGRESSIVELY
SOUTHWESTERLY OVER OUR CWA TODAY THROUGH TUESDAY AS A SHORTWAVE
HIGH PRESSURE RIDGE EXITS TO OUR EAST AND A LONGWAVE TROUGH
BEGINS OVERSPREADING THE LOCAL AREA FROM THE CENTRAL UNITED
STATES. AT THE SURFACE, OVERALL AND GRADUAL SURFACE PRESSURE
FALLS OCCUR ACROSS NORTHERN OH AND NORTHWEST PA TODAY AS A
SURFACE LOW TRACKS FROM NEAR THE SOUTHEAST SD/NORTHEAST NE
BORDER EARLY THIS MORNING TO NEAR WEST-CENTRAL WI BY MIDNIGHT
TONIGHT. THIS LOW WILL THEN TRACK TO NEAR NORTHERN LAKE SUPERIOR
BY NIGHTFALL ON TUESDAY. A WARM FRONT ACCOMPANYING THIS LOW
SHOULD CROSS OUR CWA FROM SOUTHWEST TO NORTHEAST THIS EVENING
AND THE PREDAWN HOURS OF TUESDAY, WHILE THE COLD FRONT SHOULD
FOLLOW QUICKLY AND CROSS THE CWA LATE THIS EVENING THROUGH
TUESDAY MORNING. IN ADDITION, A WARM CONVEYOR BELT WILL CROSS
OUR CWA FROM WEST TO EAST AHEAD OF THE COLD FRONT. THIS WARM
CONVEYOR BELT WILL TRANSPORT ABUNDANT MOISTURE NORTHWARD FROM
THE GULF OF MEXICO AND UNDERGO ISENTROPIC LIFT OVER OUR AREA.
LASTLY, SURFACE TROUGHING PERSISTS OVER OUR CWA BEHIND THE COLD
FRONT.
CLOUD COVER INCREASES GENERALLY FROM WEST TO EAST TODAY, WHILE
SCATTERED TO WIDESPREAD RAIN SHOWERS OVERSPREAD OUR FORECAST AREA
FROM WEST TO EAST THIS AFTERNOON AND EVENING. THESE SHOWERS WILL BE
HEAVY AT TIMES. THERE MAY BE JUST ENOUGH INSTABILITY FOR A FEW WEAK,
BRIEF THUNDERSTORMS WITHIN THE WARM CONVEYOR BELT AND ALONG THE COLD
FRONT, BUT THE POTENTIAL FOR THUNDERSTORMS REMAINS VERY LOW. THE
SWATH(S) OF RAIN AND ANY EMBEDDED THUNDERSTORMS WILL END FROM WEST
TO EAST TUESDAY MORNING AND EARLY AFTERNOON, WHILE PARTIAL AND
GRADUAL CLEARING WILL ALSO WORK ITS WAY EAST DURING THE COURSE OF
TUESDAY. THIS WIDESPREAD RAINFALL SHOULD TOTAL AROUND 0.50" TO
0.75". AS COLD AIR DEEPENS OVER WARM LAKE ERIE, A WELL-ALIGNED
SOUTHWESTERLY LOW-LEVEL FLOW MAY BEGIN TO TRIGGER SOME LAKE
EFFECT RAIN SHOWERS OVER THE CENTRAL PORTION OF THE LAKE BY
EARLY TUESDAY EVENING. HOWEVER, ANY LAKE EFFECT RAIN SHOULD BE
OFFSHORE NORTHEAST OH AND NORTHWEST PA AT THAT POINT.
DESPITE INCREASING CLOUD COVER TODAY, STRENGTHENING SOUTHEASTERLY TO
SOUTHERLY SURFACE WINDS WILL RESULT IN WARM ADVECTION REGION-WIDE
AND DOWNSLOPE FLOW FOR SOME AREAS. THUS, WE STILL EXPECT AFTERNOON
HIGHS TO REACH THE UPPER 60'S TO MID 70'S. TONIGHT THROUGH TUESDAY,
SOUTHERLY SURFACE WINDS WILL SHIFT TO SOUTHWESTERLY WITH THE PASSAGE
OF THE COLD FRONT AND THESE WINDS WILL BE GUSTY. A WIND ADVISORY HAS
BEEN ISSUED FOR NORTHERN ERIE COUNTY, PA FROM 8 PM THIS EVENING TO 6
AM EDT TUESDAY. HERE, SOUTHEASTERLY DOWNSLOPE WINDS ARE EXPECTED TO
GUST UP TO 50 MPH BETWEEN ROUGHLY I-90 AND THE LAKESHORE. GUSTY
WINDS AND ABUNDANT CLOUD COVER WILL CONTRIBUTE TO MILD LOWS IN
THE UPPER 40'S TO MID 50'S AROUND DAYBREAK TUESDAY, WITH THE
COOLEST READINGS IN THE FAR-WEST AND WARMEST READINGS FARTHER
EAST. AFTERNOON HIGHS ON TUESDAY ARE FORECAST TO REACH THE UPPER
50'S TO LOWER 60'S, WITH THE COOLEST READINGS IN THE FAR-WEST
AND HIGHER TERRAIN OF NORTHWEST PA.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/
BY TUESDAY NIGHT THE AREA WILL BE SANDWICHED BETWEEN THE FILLING LOW
ACROSS ONTARIO AND HIGH PRESSURE ACROSS THE GULF COAST STATES.
REMAINING LAKE EFFECT RAIN SHOWERS WILL BE PRIMARILY OFFSHORE, BUT
WILL CONTINUE THE MENTION OF SHOWERS RIGHT ALONG THE LAKESHORE.
RIDGING BUILDS IN TOWARD WEDNESDAY MORNING AND BY MIDDAY WEDNESDAY
WE SHOULD BE DONE WITH THE LAKE EFFECT. THE REST OF THE AREA WILL BE
FAIR WITH SEASONABLE TEMPERATURES. SOME WARM ADVECTION WILL AID
TEMPERATURES THURSDAY AND WILL SEE A NUMBER OF LOCATIONS WITH LOWER
60S. THERE ARE NOTABLE DIFFERENCES WITH THE TIMING AND AVAILABLE
MOISTURE FOR THE NEXT COLD FRONT EXPECTED TO BE HERE
THURSDAY/THURSDAY NIGHT/FRIDAY.
LONG TERM /FRIDAY THROUGH SUNDAY/
WILL HAVE TO CONTEND WITH THE MODELS RESOLVING THE NEXT SHORTWAVE TO
CARVE ITS WAY ACROSS THE NORTHERN ROCKIES, PLAINS AND MIDWEST TO END
THE WEEK. HAVE SIDED CLOSER TO THE ECMWF WHICH SEPARATES THE ENERGY
LEAVING A CLOSED LOW BEHIND ACROSS THE SOUTHERN PLAINS AND MORE
QUICKLY TAKES A SHALLOWER NORTHERN SHORTWAVE ACROSS THE GREAT LAKES
FRIDAY. WILL MAXIMIZE PRECIP CHANCES ON LATER THURSDAY NIGHT AND
FRIDAY FOR NOW WITH THE SURFACE FRONT NEARBY. WITH MORE OF A
GLANCING SHOT AT COLD AIR, WILL KEEP PRECIP TYPE ALL RAIN FOR ANY
LINGERING SHOWERS LATE FRIDAY NIGHT. WILL ALLOW FOR BRIEF HIGH
PRESSURE SATURDAY, BUT SUNDAY'S FORECAST IS MORE UNCERTAIN.
AVIATION /12Z MONDAY THROUGH FRIDAY/
SOUTHEASTERLY SURFACE WINDS SHOULD BECOME GUSTY BY ABOUT
15Z/MON. A WARM FRONT SHOULD SWEEP NORTHEASTWARD OVER THE AREA
THIS EVENING THROUGH EARLY TUESDAY MORNING, WHILE AN EASTWARD-
MOVING COLD FRONT SHOULD REACH A KTOL TO KFDY LINE AROUND
03Z/TUE AND NEAR THE OH/PA BORDER BY 12Z/TUE. SOUTHEASTERLY
SURFACE WINDS SHIFT TO SOUTHERLY WITH THE PASSAGE OF THE WARM
FRONT. THESE SOUTHERLY SURFACE WINDS WILL THEN SHIFT TO
SOUTHWESTERLY WITH THE PASSAGE OF THE COLD FRONT AND REMAIN
GUSTY. WIND GUSTS SHOULD AVERAGE 20 TO 30 KNOTS, BUT SHOULD
REACH 40 KNOTS OR SO AT/NEAR KERI BETWEEN 00Z/TUE AND 12Z/TUE.
VFR ARE EXPECTED AHEAD OF THE UPCOMING RAINFALL. RAIN SHOWERS
WILL GRADUALLY OVERSPREAD THE REGION FROM WEST TO EAST BETWEEN
18Z/MON AND 10Z/TUE. CEILINGS SHOULD TREND MVFR WITH THIS RAIN,
WITH THE POTENTIAL FOR POCKETS OF IFR CEILINGS AND MVFR
VISIBILITY IN HEAVIER SHOWERS. THERE IS A SLIGHT CHANCE FOR A
FEW THUNDERSTORMS, BUT FORECAST CONFIDENCE IN THUNDERSTORM
DEVELOPMENT REMAINS VERY LOW. RAIN SHOULD END WITHIN SEVERAL
HOURS FOLLOWING THE COLD FRONTAL PASSAGE. THUS, RAIN IS
FORECAST TO END AROUND 04Z/TUE AT KTOL AND KFDY AND SHOULD END
BY 12Z/TUE AS FAR EAST AS KCLE.
OUTLOOK
NON-VFR POSSIBLE IN WIDESPREAD SHOWERS THROUGH
TUESDAY MORNING. NON-VFR POSSIBLE IN LAKE EFFECT RAIN SHOWERS
AT/NEAR KERI TUESDAY EVENING INTO WEDNESDAY. SCATTERED SHOWERS
MAY RESULT IN NON-VFR THURSDAY AFTERNOON INTO FRIDAY.
MARINE
SOUTHEAST WINDS WILL STEADILY INCREASE TODAY. BIGGEST CONCERN FOR
SMALL CRAFT ADVISORY CONDITIONS COMES WITH STRONGER WINDS THIS
EVENING/TONIGHT EAST OF WILLOWICK AND ESPECIALLY OFF OF ERIE, PA
WITH DOWNSLOPE WINDS ADDING TO THE GUSTINESS NEAR THE SHORE. THE
COLD FRONT CROSSES OVERNIGHT/THROUGH EARLY TUESDAY MORNING.
SOUTHWEST WINDS IN ITS WAKE WILL BE ENOUGH TO NECESSITATE A SMALL
CRAFT ADVISORY FOR THE ENTIRE LAKE TUESDAY AND WEDNESDAY. WILL
LIKELY PUSH 30 KNOTS AT TIMES DURING THE TUE/WED WINDOW, BUT DO NOT
SEE GALES. WINDS COME DOWN A NOTCH WEDNESDAY NIGHT AHEAD OF THE NEXT
COLD FRONT THAT WILL ARRIVE FOR THURSDAY. EXPECT A WIND SHIFT TO THE
NORTHWEST FOR FRIDAY.
CLE WATCHES/WARNINGS/ADVISORIES
OH...NONE.
PA...WIND ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT TUESDAY FOR
PAZ001.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
TUESDAY FOR LEZ147>149.
SYNOPSIS...JASZKA
NEAR TERM...JASZKA
SHORT TERM...OUDEMAN
LONG TERM...OUDEMAN
AVIATION...JASZKA
MARINE...OUDEMAN
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