708
FXUS61 KCLE 011145
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
645 AM EST SUN DEC 1 2024
SYNOPSIS
A SURFACE TROUGH WILL CONTINUE TO IMPACT THE AREA INTO TUESDAY
BEFORE A BRIEF RIDGE BUILDS ACROSS THE OHIO RIVER VALLEY INTO
WEDNESDAY. ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE GREAT LAKES
REGION WEDNESDAY THROUGH THURSDAY BEFORE HIGH PRESSURE RETURNS
FRIDAY.
NEAR TERM /THROUGH MONDAY/
630 AM UPDATE...
A HEAVY BAND OF LAKE EFFECT SNOW HAS SHIFTED SOUTH AND IS
COMING ONSHORE NEAR GENEVA IN LAKE COUNTY. IN THIS BAND,
VISIBILITIES ARE QUICKLY BEING REDUCED WITH SNOWFALL RATES OF
1-2"/HR. THIS BAND IS EXPECTED TO PERSIST, SHIFTING NORTH/SOUTH
SLIGHTLY THROUGHOUT THE DAY. OVERALL THE FORECAST REMAINS
UNCHANGED WITH THIS UPDATE WITH THE EXCEPTION OF SLIGHT
ADJUSTMENTS TO TEMPERATURES TO REFLECT CURRENT OBSERVATIONS.
PREVIOUS DISCUSSION...
THE FORECAST TODAY IS ESSENTIALLY THE SAME STORY, JUST A DIFFERENT
DAY AS HEAVY LAKE EFFECT SNOW CONTINUES TO IMPACT THE PRIMARY
SNOWBELT REGION, PERSISTING THROUGH MONDAY. THE BROAD UPPER LEVEL
TROUGH ACROSS THE EASTERN CONUS CONTINUES TO DIG SOUTH WHILE A
SURFACE TROUGH LINGERS OVER THE GREAT LAKES REGION. COLD 850MB
TEMPERATURES OF -10 TO -12C WILL CONTINUE TO ADVECT ACROSS LAKE ERIE
WHOSE TEMPERATURES CONTINUES TO HOVER AROUND 8C. THIS WILL ALLOWED
FOR THE CONTINUATION OF MODERATE LAKE INDUCED INSTABILITY WORKING TO
AMPLIFY THE ONGOING LAKE EFFECT BAND. IN ADDITION, A SHORTWAVE
TROUGH SHOULD HELP PROVIDE SUPPORT FOR A MORE ORGANIZED BAND TO
REDEVELOP. MODELS SOUNDINGS CONTINUE TO SUGGEST STRONG OMEGA
THROUGHOUT THE DGZ WITH STEEPENING LAPSE RATES WHICH WILL ALSO AID
IN ENHANCING THIS BAND OF LAKE EFFECT. FINALLY, HI-RES MODELS
CONTINUE TO SUGGEST A STRONG CONVERGENT BOUNDARY BEING MAINTAINED
ALONG THE SOUTHERN SHORE OF LAKE ERIE. WITH THE OVERALL MESOSCALE
SET-UP, THERE IS HIGH CONFIDENCE THAT AREAS ACROSS THE SNOWBELT
REGION WILL AGAIN BE IMPACTED WITH HEAVY SNOWFALL WITH RATES OF 1-
2"/HR. WITH THE DURATION OF THIS ROUND OF LAKE EFFECT AND THE
EXPECTED RATES, AREAS ALONG THE LAKESHORE (PRIMARILY I-90 AND NORTH)
ARE EXPECTED TO GET AN ADDITIONAL 12-20" OF SNOWFALL, BRINGING SOME
AREAS TO 4-6 FEET FOR THE TOTAL SNOWFALL FOR THIS EVENT.
THE BIGGEST UNCERTAINTY WITH THIS NEXT ROUND OF LAKE EFFECT IS WHERE
THE BAND WILL PERSIST AND HOW FAR INLAND THIS BAND WILL PUSH.
CURRENT RADAR IMAGERY PLACES A BAND OF HEAVY SNOW OVER LAKE COUNTY
AND EAST. WITH A COLDER AIRMASS TO THE SOUTH, CURRENT THINKING IS
THAT THIS BAND OF LAKE EFFECT WILL CONTINUE TO HUG THE SOUTHERN
LAKESHORE WHERE A STRONG CONVERGENT BOUNDARY EXISTS BEFORE A
STRONGER NORTHWEST FLOW COMPONENT KICKS IN LATE THIS EVENING,
SHIFTING THE BAND FURTHER INLAND. WHEN THIS OCCURS, SNOWFALL WILL
BECOME MORE WIDESPREAD ACROSS THE NORTHERN PORTION OF GEAUGA AND
CRAWFORD (PA) COUNTY AND NORTHEASTERN CUYAHOGA COUNTY, WHICH ARE
BOTH IN A LAKE EFFECT SNOW WARNING. TOTALS ACROSS THESE COUNTIES
WILL BE 6 TO 14 INCHES, WITH HIGHEST TOTALS ACROSS THE
AFOREMENTIONED AREAS. AS ONE MOVES SOUTH IN BOTH COUNTIES, TOTALS
WILL QUICKLY DIMINISH TO ONLY BEING 1-3". WILL HAVE TO CONTINUE TO
MONITOR FOR ANY SHIFT IN THE LAKE EFFECT BAND FOR ANY ADJUSTMENTS
NEEDED TO THE SNOWFALL TOTALS.
IT IS IMPORTANT TO NOTE THAT THIS SECOND ROUND OF SNOWFALL WILL ONLY
COMPOUND THE IMPACTS FELT FROM THE FIRST ROUND. EXPECT TRAVEL ACROSS
THESE COUNTIES, ESPECIALLY ALONG PORTIONS OF I-90, I-86, AND I-79,
TO BECOME EXTREMELY DIFFICULT, POSSIBLY IMPASSABLE AGAIN. WITHIN THE
HEAVIEST BAND, VISIBILITIES WILL QUICKLY BE REDUCED TO 1/4SM OR
LESS. IN ADDITION, GUSTY WINDS NEAR THE LAKESHORE MAY RESULT IN
BLOWING OF SNOW THAT HAS ALREADY FALLEN. PLEASE DO NOT VENTURE IN TO
THESE AREAS AS TRAVELING WILL AGAIN BE EXTREMELY DANGEROUS AND
FOLLOW GUIDANCE FROM LOCAL OFFICIALS.
HIGH TEMPERATURES THROUGH THIS PERIOD WILL REACH INTO THE UPPER 20S
TO LOW 30S WITH COLD OVERNIGHT TEMPERATURES DROPPING INTO THE UPPER
TEENS TO LOW 20S. OVERNIGHT WIND CHILL VALUES MAY REACH SINGLE
DIGITS, ESPECIALLY ACROSS THE SOUTHERN TIER OF COUNTIES.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
THE MULTI-DAY LAKE EFFECT EVENT WILL CONTINUE FOR THE START OF THE
SHORT TERM FORECAST PERIOD. THE SETUP FOR MONDAY NIGHT REMAINS
INTRIGUING AS A SHORTWAVE WILL MOVE THROUGH THE BROADER UPPER TROUGH
OVER THE EASTERN CONUS AND THIS SHOULD ENHANCE THE LIFT AND SNOW
ACROSS THE REGION. HOWEVER, THIS SHORTWAVE WILL ALSO ALLOW FOR FLOW
TO VEER SOME MORE AND THE UPSTREAM MOISTURE/SNOW CONNECTION FROM
LAKE HURON SHOULD ENTER INTO NORTHWEST PENNSYLVANIA, ENHANCING
SNOWFALL THERE. THERE SHOULD ALSO BE A MORE POTENT BAND IN NE OH,
WHICH MAY PIVOT FROM LAKE AND NORTHERN GEAUGA COUNTIES TOWARD THE
TRIPLE POINT OF CUYAHOGA, LAKE, AND GEAUGA COUNTIES. THIS BAND WILL
HAVE SOME ADDED LAKE ENHANCEMENT FROM LAKE ST. CLAIR AND EVEN
SAGINAW BAY. ONCE THE SHORTWAVE PASSES, THERE WILL BE SOME DRIER,
CONTINENTAL AIR THAT WILL ENTER THE REGION AND THIS SHOULD REDUCE
THE OVERALL EFFICIENCY OF THE LAKE EFFECT AND THE 6 HR SNOWFALL
TOTALS SHOULD DRAMATICALLY FALL OFF AFTER MIDNIGHT MONDAY NIGHT. THE
LAKE EFFECT SNOW WARNINGS ARE VALID THROUGH 7 AM TUESDAY AND THIS
SHOULD ENCAPSULATE ALL OF THE REMAINING SIGNIFICANT SNOW FOR THE
EVENT.
HIGH PRESSURE OVER LOWER OHIO VALLEY WILL START TO ADVANCE INTO THE
FORECAST AREA ON TUESDAY AND ALLOW FOR FLOW TO BACK ACROSS THE
REGION. THIS WILL SHIFT ANY ONGOING LAKE EFFECT SNOW NORTH AND
EVENTUALLY BACK OVER LAKE ERIE. TOTALS ON TUESDAY SHOULD BE FAIRLY
LIGHT, BUT THERE IS A CHANCE THE WARNING COULD GET EXTENDED FOR ERIE
PA OR REPLACED WITH A BRIEF ADVISORY. AS THIS SYSTEM ENTERS THE
REGION, TEMPERATURES WILL WARM SLIGHTLY AND DRIER AIR WILL MOVE
OVERHEAD, WHICH SHOULD ALLOW FOR A BREAK IN THE SNOW AT SOME POINT
ON TUESDAY AFTERNOON AND EVENING. A POTENT LOW PRESSURE SYSTEM WILL
ENTER THE GREAT LAKES REGION FROM THE NORTHWEST ON WEDNESDAY AND
WILL BRING WIDESPREAD PRECIPITATION TO THE FORECAST AREA. FOR THE
MOST PART, PRECIPITATION SHOULD FALL AS SNOW, BUT SOME CHANGEOVER TO
RAIN COULD OCCUR, ESPECIALLY IN THE WESTERN FORECAST AREA, AS
TEMPERATURES MAY GET TOO FAR ABOVE FREEZING. A COLD FRONT WILL MOVE
ACROSS THE AREA ON WEDNESDAY NIGHT AND ENHANCE SNOWFALL. THIS WILL
ALSO TURN THE LAKE EFFECT MACHINE BACK ON AND HAVE THE HIGHEST POPS
FOCUSED IN NE OH AND NW PA. TEMPERATURES THROUGH THE PERIOD WILL
REMAIN BELOW NORMAL WITH 30S FOR HIGHS AND 20S FOR LOWS.
LONG TERM /THURSDAY THROUGH SATURDAY/
A LOW PRESSURE SYSTEM WILL MOVE EAST OF THE GREAT LAKES REGION ON
THURSDAY WITH A COLD FRONT EAST OF THE AREA ON THURSDAY MORNING.
SNOW SHOULD STILL BE IN THE REGION BEHIND THE SYSTEM, FAVORING THE
SNOW BELT ONCE AGAIN. UNLIKE THE CURRENT EVENT, THE AIR MASS FOR
LATE IN THE WEEK APPEARS A BIT DRIER AND THE WINDS WILL BE MUCH
STRONGER - BOTH FACTORS LIKELY REDUCING THE END EFFICIENCY OF THE
EVENT. HOWEVER, THE AIR MASS WILL BE COLDER AND THE DURATION OF SNOW
WILL BE AT LEAST THURSDAY AND FRIDAY. THERE COULD BE THE NEED FOR AT
LEAST AN ADVISORY TYPE OF HEADLINE WITH THIS SETUP, BUT THERE IS
STILL TIME FOR DETAILS TO COME TOGETHER. A LOW LEVEL RIDGE WILL
ENTER EARLY ON SATURDAY TO END THE LAKE EFFECT, BUT ANOTHER LOW
PRESSURE SYSTEM WILL TARGET THE GREAT LAKES REGION FOR THE WEEKEND
BRINGING MORE CHANCES FOR PRECIPITATION. OVERALL, TEMPERATURES WILL
BE BELOW NORMAL WITH HIGHS GENERALLY IN THE 30S AND LOWS GENERALLY
IN THE TEENS.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
WIDESPREAD VFR CONDITIONS WITH WEST-SOUTHWEST OF 5-10 KNOTS WILL
PERSIST FOR ALL TERMINALS OUTSIDE OF THE SNOWBELT THIS TAF
PERIOD.
PERIODS OF MVFR TO LIFR CONDITIONS ARE POSSIBLE AT KERI AND KCLE
AS LAKE EFFECT SNOW IMPACTS THE TERMINALS. THE HIGHEST
CONFIDENCE IN VISIBILITIES LESS THAN 1SM IS AT KERI THROUGHOUT
THE PERIOD, ESPECIALLY GIVEN WIND GUSTS OF 20-25 KNOTS FROM THE
WEST-SOUTHWEST POTENTIALLY BLOWING SNOW. NOT EXPECTING AS HARSH
OF CONDITIONS AT KCLE AS A LAKE EFFECT SNOW BAND SAGS SOUTH
THIS EVENING INTO THE OVERNIGHT HOURS. THE BULK OF IMPACTS
SHOULD BE FROM THE CLEVELAND METRO EAST THROUGH THE SNOWBELT
WITH THE TAIL END CLIPPING THE TERMINALS AND POSSIBLY REDUCING
CONDITIONS TO MVFR VISIBILITIES/HEIGHTS. WILL CONTINUE TO
MONITOR THIS POTENTIAL, BUT GIVEN THE UNCERTAINTY, OPTED TO
REMAIN MORE OPTIMISTIC FOR KCLE.
OUTLOOK...NON-VFR LIKELY IN LAKE-EFFECT SNOW BANDS THROUGH
TUESDAY. THE HEAVIEST AND MOST-PERSISTENT LAKE-EFFECT SNOW IN
OUR REGION IS EXPECTED TO IMPACT THE PRIMARY SNOWBELT IN FAR
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA.
MARINE
THE LAKE AGGREGATE TROUGH REMAINS IN PLACE FOR TODAY AND MONDAY
AND WILL ALLOW FOR ELEVATED WESTERLY FLOW FOR THE NEXT TWO
DAYS. THE WINDS AT THE IMMEDIATELY LAKE SHORE HAVE BEEN LOWER
WITH MORE INFLUENCE BY THE LAKE EFFECT SNOW BANDS OVER THE
CENTRAL AND EASTERN BASINS. FOR TUESDAY, HIGH PRESSURE WILL
STRENGTHEN TO THE SOUTHWEST OF THE LAKE AND PUSH THE TROUGH OUT
OF THE REGION. HOWEVER, THERE WILL BE A STRONGER PRESSURE
GRADIENT THAT WILL ALLOW FOR MARGINALLY STRONG ENOUGH FLOW TO
KEEP WAVES ELEVATED OVER THE CENTRAL AND EASTERN BASINS ON
TUESDAY. FOR WEDNESDAY AND THURSDAY, A POTENT LOW PRESSURE
SYSTEM WILL MOVE THROUGH THE GREAT LAKES REGION AND EXTEND A
COLD FRONT ACROSS THE LAKE. SOUTHWEST WINDS WILL INCREASE
GREATLY AHEAD OF THE SYSTEM ON WEDNESDAY AND WINDS COULD MAKE A
RUN TOWARD GALE FORCE. THE COLD FRONT WILL MOVE THROUGH BY
THURSDAY AND WINDS WILL SHIFT TO THE WEST AND THEN NORTHWEST.
THE PRESSURE GRADIENT BEHIND THE FRONT WILL BE STRONG AND THERE
COULD BE AN EVEN BETTER CHANCE FOR GALE FORCE WINDS ON THURSDAY.
FOR NOW, WILL RETAIN THE SMALL CRAFT ADVISORY FOR VERMILION AND
EAST THROUGH 7 AM ON WEDNESDAY. AFTER THIS TIME PERIOD, THERE
WILL NEED TO BE AN EXTENSION OF THIS ADVISORY OR POTENTIALLY A
GALE HEADLINE.
CLE WATCHES/WARNINGS/ADVISORIES
OH...LAKE EFFECT SNOW WARNING FROM NOON TODAY TO 7 AM EST TUESDAY
FOR OHZ011-013.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR OHZ012-014-
089.
PA...LAKE EFFECT SNOW WARNING FROM NOON TODAY TO 7 AM EST TUESDAY
FOR PAZ003.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR PAZ001-002.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR LEZ145>149.
SYNOPSIS...CAMPBELL
NEAR TERM...CAMPBELL
SHORT TERM...SEFCOVIC
LONG TERM...SEFCOVIC
AVIATION...CAMPBELL
MARINE...SEFCOVIC
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