209
FXUS61 KCLE 031420
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
920 AM EST TUE DEC 3 2024
SYNOPSIS
HIGH PRESSURE WILL BUILD FROM THE WEST TODAY AND SLIDE SOUTH
THROUGH THE OHIO AND TENNESSEE VALLEYS. LOW PRESSURE WILL ENTER
THE NORTHERN GREAT LAKES ON WEDNESDAY AND EXTEND A STRONG COLD
FRONT THROUGH THE AREA ON WEDNESDAY NIGHT. A TROUGH WILL REMAIN
OVER THE LAKE FOR THURSDAY BEFORE HIGH PRESSURE RETURNS FOR
FRIDAY.
NEAR TERM /THROUGH WEDNESDAY/
9:20 AM UPDATE...
CONTINUED LAKE EFFECT SNOW SHOWERS ACROSS EXTREME NORTHEAST
OHIO AND NORTHWEST PENNSYLVANIA THIS MORNING STEMMING FROM A
LAKE HURON CONNECTION WILL BRING ANOTHER 2-4 INCHES OF SNOW,
WITH LOCALLY 4-6 INCHES IN EXTREME EASTERN ERIE COUNTY, PA.
EXPECT FOR ANY LINGERING LAKE EFFECT SNOW TO DIMINISH AS LOW
LEVEL RIDGING BUILDS OVER THE REGION FROM THE WEST.
PREVIOUS DISCUSSION...
THE MULTI-DAY LAKE EFFECT SNOW EVENT THAT BEGAN THANKSGIVING
NIGHT IS IN ITS FINAL PHASE TODAY, AS DRY AIR AND HIGH PRESSURE
ENTERING THE REGION ARE FINALLY ALLOWING FOR SNOW BANDS TO
DIMINISH. DRY AIR ACROSS THE REGION HAS BEEN EFFICIENT IN
CUTTING DOWN CLOUD COVER OVERHEAD. BACKING FLOW ENTERING
NORTHERN OHIO IS ALREADY STARTING TO WEAKEN THE LAKE EFFECT
BANDS ACROSS THE REGION AND THERE ARE JUST SOME MINOR SNOW
SHOWERS EAST OF CLEVELAND IN LAKE AND GEAUGA COUNTIES THIS
MORNING WITH ESSENTIALLY NO SNOW IN ASHTABULA COUNTY. ANY
REMAINING SNOW TODAY WILL BE ON ACCOUNT OF ANY INFLUENCE FROM
UPSTREAM LAKES AND THE LAKE HURON CONNECTION CONTINUES TO FAVOR
NORTHWEST PENNSYLVANIA. WITH THAT, HAVE GONE AHEAD AND ENDED THE
LAKE EFFECT SNOW WARNINGS AND WINTER WEATHER ADVISORY IN OHIO,
AS AN INCH OR SO OF SNOW SEEMS POSSIBLE THROUGH THE DAYTIME
HOURS TODAY AND ANY REMAINING IMPACTS FROM ONGOING WEATHER WILL
BE MINIMAL. FOR NORTHWEST PA, THE ENVIRONMENT REMAINS FAVORABLE
FOR SEVERAL MORE INCHES OF NEW ACCUMULATIONS WITH THE BULK IN
NORTH EAST AND GREENFIELD TOWNSHIPS IN ERIE COUNTY, PA BUT A
CONTOUR OF 4 OR MORE EXTENDING TO MCKEAN, EDINBORO, WATERFORD,
AND CANADOHTA LAKE. WILL HAVE THE WARNINGS FOR ERIE AND CRAWFORD
COUNTIES IN PA GO THROUGH 7 PM THIS EVENING, OR THE WINDOW WHEN
THE LAKE HURON CONNECTING BAND COULD RETAIN INFLUENCE INTO THE
FORECAST AREA.
THE LOW LEVEL RIDGE AXIS WILL BE ACROSS THE AREA TONIGHT AND
EFFECTIVE END THE SNOW THREAT FOR A PERIOD. CLOUDS ACROSS THE
REGION AHEAD OF THIS FEATURE WILL LIMIT DECOUPLING WITH A DRY
FORECAST, BUT COLD CONDITIONS WITH LOWS IN THE 20S WILL REMAIN
FOR TONIGHT.
FOR WEDNESDAY, A STRONG LOW PRESSURE SYSTEM WILL ENTER THE GREAT
LAKES REGION FROM THE NORTH. WITH THIS SYSTEM TO THE NORTH AND A
DEPARTING HIGH PRESSURE SYSTEM TO THE SOUTHEAST, THERE WILL BE A
STRONG PRESSURE GRADIENT ACROSS THE REGION, ALONG WITH AN
INCOMING 55 KT 850 MB JET. THIS WILL SUPPORT INCREASING SURFACE
WINDS DURING THE AFTERNOON, INCLUDING WIND GUSTS TO 45 MPH.
THERE IS A CHANCE THAT A WIND ADVISORY COULD BE NEEDED IF THE
JET ENERGY ENTERING THE REGION IS A BIT STRONG IN COMING DOWN TO
THE SURFACE. THIS JET WILL BE AHEAD OF A COLD FRONT THAT WILL
BRING WIDESPREAD RAIN/SNOW TO THE REGION. WHILE MEAN GUIDANCE
HAS RAIN ALMOST EVERYWHERE, SUSPECT THAT THE AIR MASS REMAINS
COOL ENOUGH AHEAD OF THE SYSTEM THAT THE PREVAILING
PRECIPITATION TYPE WILL TRY TO STAY AS ALL SNOW AND HAVE EITHER
ALL SNOW OR RAIN/SNOW IN THE FORECAST. IMPACTS WILL THEN
DETERIORATE AS THE ARCTIC FRONT ENTER THE REGION. FOR
INFORMATION ON THE LATE WEDNESDAY AFTERNOON AND BEYOND SNOW
FORECAST, INCLUDING THE NEWLY ISSUED WINTER STORM WATCH, PLEASE
SEE THE LONG TERM DISCUSSION BELOW.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/
A POTENT UPPER LEVEL TROUGH WITH A DEEPENING SURFACE LOW CENTERED
OVER SOUTHERN QUEBEC/ONTARIO WILL MOVE A STRONG COLD FRONT EAST
ACROSS THE AREA WEDNESDAY NIGHT, MARKING THE START TO ANOTHER
IMPACTFUL WEATHER PERIOD. THE BEGINNING OF THIS EVENT WEDNESDAY
NIGHT WILL BE PREDOMINATELY SYNOPTICALLY DRIVEN AS A STRONG VORT MAX
AND UPPER LEVEL JET PUSH ACROSS THE OHIO RIVER VALLEY. AN ASSOCIATED
LLJ OF 55-65 KNOTS WILL PROCEED THE BOUNDARY, WEAKENING TO 40-50
KNOTS BEHIND THE FRONT. THIS WILL ADD ADDITIONAL SUPPORT TO THE
STRONG FRONTOGENETIC FORCING ALONG THE BOUNDARY AND RESULT IN
WIDESPREAD SNOW SHOWERS ACROSS THE AREA. MOST AREAS WITH THIS
INITIAL PUSH WILL ONLY SEE A TRACE TO UP TO 0.5", ALTHOUGH SOME
LOCALLY HEAVY BANDS MAY PRODUCE MORE AS SNOW SQUALLS ARE A
POSSIBILITY OVERNIGHT WEDNESDAY GIVEN THE STRONG PRESSURE CHANGES
WITH THE PASSING OF THE BOUNDARY AND STEEPENING LAPSE RATES. EITHER
WAY, WITH STRONG SURFACE WINDS EXPECTED, BLOWING SNOW WILL LIKELY BE
AN ISSUE AND RESULT IN REDUCTIONS IN VISIBILITIES THROUGH THURSDAY.
WIND GUSTS ARE CURRENTLY FORECAST TO BE AS HIGH AS 40 MPH WITH
SUSTAINED WINDS OF 20-30 MPH THROUGH THURSDAY BEFORE THE GRADIENT
WEAKENS AND WINDS DECREASE TO 10-15 MPH ON THURSDAY NIGHT WITH THE
EXCEPTION OF NEAR THE LAKESHORE WHICH WILL REMAIN ELEVATED DUE TO
STRONG NORTHWEST FLOW OFF OF LAKE ERIE.
THE STRONG NORTHWEST FLOW ACROSS LAKE ERIE IS A PERFECT TRANSITION
INTO THE NEXT EXPECTED HAZARD THAT WILL PERSIST THROUGH THE
REMAINDER OF THE SHORT TERM PERIOD. AS WINDS BACK BEHIND THE
DEPARTING COLD FRONT, 850MB TEMPERATURES WILL QUICKLY PLUNGE TO -12
TO -14C ACROSS LAKE ERIE WHOSE AVERAGE TEMPERATURE IS CURRENTLY 7C
RESULTING IN MODERATE LAKE INDUCED INSTABILITY. MODELS ARE IN
AGREEMENT WITH A STRONG CONVERGENT BOUNDARY BECOMING ESTABLISHED
ALONG THE SNOWBELT, COINCIDING WITH AN AREA OF STRONG OMEGA LIFT.
WITH PLENTY OF MOISTURE WRAPPING AROUND THE PARENT LOW, THIS SHOULD
RESULT IN ANOTHER EFFICIENT, HEAVY ROUND OF LAKE EFFECT SNOW FOR THE
SNOWBELT THROUGH AT LEAST THURSDAY NIGHT. THIS SECOND EVENT MAY
COMPOUND THE IMPACTS ALREADY FELT FROM THE LONG DURATION EVENT OVER
THE LAST COUPLE DAYS. CURRENTLY, THE FORECAST STORM TOTAL SNOWFALL
FOR THIS EVENT BEGINNING WEDNESDAY NIGHT THROUGH THURSDAY EVENING
HAS AN ADDITIONAL 10-15" FALLING ACROSS PORTIONS OF THE PRIMARY
SNOWBELT. THERE IS HIGH CONFIDENCE IN WIDESPREAD SNOWFALL ACROSS THE
SNOWBELT, BUT EXACT LOCATION REMAINS A BIT UNCERTAIN GIVEN THE MULTI-
BAND NATURE OF THIS EVENT. TO FURTHER HIGHLIGHT THIS POTENTIAL
IMPACTFUL EVENT, HAVE OPTED TO ISSUE A WINTER STORM WATCH FOR
COUNTIES ACROSS THE SNOWBELT.
TO FIND A SILVER LINING IN THE FORECAST, THE ASSOCIATED UPPER LEVEL
TROUGH IS MUCH QUICKER TO SHIFT EAST, ALLOWING FOR THE INTENSITY IN
SNOW SHOWERS TO GRADUALLY TAPER THROUGH FRIDAY NIGHT WITH MORE
SCATTERED SNOW SHOWERS EXPECTED. HIGH TEMPERATURES ON THURSDAY AND
FRIDAY WILL SHIFT BACK TO BELOW NORMAL, ONLY CLIMBING INTO THE MID
TO UPPER 20S, POSSIBLY TOUCHING 30 ALONG THE LAKESHORE. OVERNIGHT
LOWS WILL LINGER IN THE UPPER TEENS TO LOW 20S. GIVEN THE STRONG
WINDS EXPECTED WEDNESDAY NIGHT, OVERNIGHT WIND CHILL TEMPERATURES
WILL LIKELY DROP INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA.
LONG TERM /SATURDAY THROUGH MONDAY/
A BROAD UPPER LEVEL TROUGH WILL LINGER OVER THE NORTHEASTERN US
THROUGH THE WEEKEND, ALTHOUGH MODELS DIVERGE QUITE A BIT IN THE
PLACEMENT OF THE TROUGH AND THE MOVEMENT OF ANY ASSOCIATED SURFACE
LOWS. LONG RANGE MODELS, INCLUDING THE ECMWF AND CANADIAN SUGGEST A
WEAK SURFACE LOW MOVING ACROSS THE GREAT LAKES REGION SATURDAY INTO
SUNDAY, ALTHOUGH THIS SYSTEM APPEARS TO ONLY CLIP THE NORTHERN TIER
OF COUNTIES AND MAY ONLY RESULT IN SOME LIGHT SNOW SHOWERS ACROSS
THE SNOWBELT. HIGH PRESSURE SHOULD BUILD OVER THE AREA ON SUNDAY,
MARKING A TRANSITION TO A WAA REGIME WITH HIGHS ON SUNDAY CLIMBING
INTO THE UPPER 30S TO LOW 40S AND MONDAYS HIGHS IN THE 40S. ON
MONDAY, THERE REMAINS QUITE A BIT OF UNCERTAINTY, BUT GENERAL
THOUGHT IS THAT A LOW PRESSURE SYSTEM MOVES NORTHEAST OUT OF THE
SOUTHERN PLAINS, BRINGING WIDESPREAD SHOWERS TO THE AREA. WILL HAVE
TO MONITOR THIS AS RAINFALL ON TOP OF THE PLETHORA OF SNOW THAT HAS
FALLEN ACROSS THE SNOWBELT MAY LEAD TO LOCALIZED FLOODING CONCERNS.
OVERNIGHT LOWS THROUGH THE PERIOD WILL LINGER IN THE 30S.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
LAKE EFFECT SNOW CONTINUES TO IMPACT KERI WITH MOSTLY MVFR
CONDITIONS, ALTHOUGH A BAND OF SNOW WILL ENTER FROM THE NORTH
THIS MORNING AND BRING BRIEF IFR VISIBILITY. LAKE EFFECT SNOW
OFF LAKE MICHIGAN WILL SPILL INTO NORTHWEST OHIO THIS MORNING
AND ALLOW FOR SOME IFR INTO KTOL OVER THE NEXT COUPLE OF HOURS.
AN AREA OF IFR CEILINGS HAS DEVELOPED OVER THE CENTRAL PORTION
OF THE FORECAST AREA AND WILL BE AT KMFD, KCAK, AND KCLE OVER
THE NEXT SEVERAL HOURS THIS MORNING. TRENDS WILL BE THAT NON-VFR
CLOUDS WILL FILL IN ACROSS THE REGION WITH ALL TERMINALS
IMPACTED TO SOME CAPACITY WITH MVFR AND IFR. HIGH PRESSURE WILL
BUILD FROM THE WEST AND ALLOW FOR THE LAKE EFFECT AND SOME OF
THE LOWER CLOUDS TO EXIT THE REGION WITH A TREND TO VFR AT ALL
TERMINALS. A STRONG LOW PRESSURE SYSTEM WILL TARGET THE REGION
FOR WEDNESDAY. IMPACTS WITH LOW CEILINGS, RAIN, AND SNOW WILL BE
DELAYED TO AFTER THE TAF PERIOD. HOWEVER, WINDS WILL BEGIN TO
INCREASE FOR THE SECOND HALF OF THE TAF PERIOD AND HAVE GUSTS
OVER 20 KT WITH SOME 30 KT MENTIONED, MAINLY OUT OF THE
SOUTHWEST.
OUTLOOK...NON-VFR LIKELY IN SNOW SHOWERS LATE WEDNESDAY THROUGH
EARLY FRIDAY, ESPECIALLY IN NE OHIO AND NW PA. NON-VFR POSSIBLE
WITH ADDITIONAL SNOW SHOWERS SATURDAY.
MARINE
HAZARDOUS MARINE CONDITIONS ARE EXPECTED TO CONTINUE FOR MUCH OF
THIS WEEK AS ANOTHER IMPACTFUL SYSTEM ARRIVES WEDNESDAY THROUGH
THURSDAY. THIS MORNING, A LINGER SURFACE TROUGH HAS MAINTAINED
NORTHWEST WINDS OF 10-20 KNOTS WITH WAVES HEIGHTS ACROSS THE CENTRAL
AND EASTERN BASINS LINGERING AT 4-6 FEET. AS HIGH PRESSURE ARRIVES
TODAY, WINDS WILL GRADUALLY BECOME SOUTHWEST, QUICKLY INCREASING TO
20-25 KNOTS. TO HIGHLIGHT THESE CONDITIONS, A SMALL CRAFT ADVISORY
REMAINS IN EFFECT UNTIL 14Z WEDNESDAY FOR THE CENTRAL AND EASTERN
BASINS.
AS A DEEPENING LOW PRESSURE SYSTEM MOVES EAST ACROSS THE NORTHERN
GREAT LAKES, WINDS WILL INCREASE WEDNESDAY TO GALE FORCE ACROSS THE
CENTRAL AND EASTERN BASINS. INITIAL OFFSHORE FLOW WILL KEEP WAVES 1-
3 FEET ACROSS THE SOUTHERN LAKESHORE, BUT AS A COLD FRONT PUSH EAST
WEDNESDAY NIGHT WINDS WILL SHIFT TO NORTHWESTERLY AT GALE FORCE,
INCREASING WAVES TO 8-10 FEET, OCCASIONALLY UP TO 14 FEET. THESE
CONDITIONS WILL PERSIST THROUGH THURSDAY EVENING AND ARE HIGHLIGHTED
IN A GALE WATCH. IN ADDITION, THE STRONG SOUTHWEST FLOW AHEAD OF THE
BOUNDARY WILL DECREASE WATER LEVELS ACROSS THE WESTERN BASIN WITH
THE CURRENT FORECAST DROPPING NEAR 2 FEET BELOW CRITICAL MARK FOR
SAFE NAVIGATION. A LOW WATER ADVISORY WILL LIKELY BE NEEDED FOR THIS
HAZARD.
AS THE LOW PRESSURE DRIFTS EAST, WINDS WILL GRADUALLY WEAKEN TO 15-
25 KNOTS THROUGH FRIDAY AS HIGH PRESSURE BUILDS EAST. MARINE
CONDITIONS ARE EXPECTED TO REMAIN HAZARDOUS AND A SMALL CRAFT WILL
LIKELY BE NEEDED INTO THE WEEKEND.
CLE WATCHES/WARNINGS/ADVISORIES
OH...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR OHZ011>014-089.
PA...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR PAZ001>003.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST WEDNESDAY FOR LEZ144>149.
GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY AFTERNOON
FOR LEZ144>149-164>169.
SYNOPSIS...SEFCOVIC
NEAR TERM...IVERSON/SEFCOVIC
SHORT TERM...CAMPBELL
LONG TERM...CAMPBELL
AVIATION...SEFCOVIC
MARINE...CAMPBELL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page