751
FXUS61 KCLE 300958
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
458 AM EST SAT NOV 30 2024
SYNOPSIS
A SURFACE TROUGH WILL CONTINUE TO IMPACT THE AREA INTO NEXT WEEK
BEFORE A BRIEF RIDGE TRIES TO BUILD NORTH ON TUESDAY INTO WEDNESDAY.
ANOTHER LOW PRESSURE WILL MOVE EAST INTO QUEBEC BY THURSDAY, MOVING
AN ASSOCIATED COLD FRONT EAST WEDNESDAY NIGHT.
NEAR TERM /THROUGH SUNDAY/
STARTING OUT LOOKING AT THE BIG PICTURE, A BROAD UPPER LEVEL TROUGH
CONTINUES TO MEANDER EAST AS A PERSISTENT SURFACE TROUGH IMPACTS THE
GREAT LAKES REGION. THE POSITIONING OF THIS TROUGH HAS ALLOWED FOR A
CONTINUED CAA REGIME TO PERSIST ACROSS THE REGION WITH 850MB
TEMPERATURES FALLING TO -10 TO -14C. AT THE SURFACE, THIS HAS
RESULTED IN THE COLDEST TEMPERATURES FELT SO FAR THIS SEASON, WITH
CURRENT OBSERVATIONS IN THE UPPER TEENS TO LOW 20S. IN ADDITION,
THIS AIRMASS REMAINS VERY DRY, WHICH IS ALLOWING FOR MUCH OF THE
AREA TO REMAIN DRY THROUGH SUNDAY WITH THE EXCEPTION OF A FEW
SCATTERED LIGHT SNOW SHOWERS IN FAR NWOH AND ACROSS THE HIGHER
TERRAIN WHICH WILL PRIMARILY BE A RESULT OF LAKE EFFECT SNOW SHOWERS
OFF OF LAKE MICHIGAN. OPTED TO CAP THE POPS AT SLIGHT CHANCE. THESE
SNOW SHOWERS ARE EXPECTED TO RESULT IN LITTLE TO NO ACCUMULATION OR
NOTABLE IMPACTS OUTSIDE OF THE SNOWBELT.
SHIFTING GEARS TO FOCUS ON THE SNOWBELT WHERE WIDESPREAD IMPACTS ARE
ONGOING FROM THE PERSIST HEAVY LAKE EFFECT SNOW BANDS. THE LATEST
BAND IS COMING ONSHORE AND IMPACTING LAKE CO. EAST THROUGH ERIE CO.
PA WITH SNOWFALL RATES OF 1-2"/HR. WITH THESE RATES, ROAD CREWS WILL
BE UNABLE TO KEEP UP WITH THEM AND IT IS ADVISED TO NOT TRAVEL
UNLESS ABSOLUTELY NECESSARY. TRAVEL IN PORTIONS OF THESE COUNTIES IS
NEARLY IMPOSSIBLE WITH LARGE STRETCHES OF I90 AND I86 CLOSED. SOME
SNOWFALL TOTALS HAVE ALREADY EXCEEDED 30" AND IS EXPECTED TO
CONTINUE TO DEEPEN IN THE COMING DAYS AS AN IDEAL LAKE EFFECT SET-UP
PERSISTS.
FOCUSING SOLELY WITHIN THIS TIME PERIOD (ENDING AT 00Z MONDAY), A
PERSISTENT SURFACE TROUGH WILL MAINTAIN A PREDOMINANTLY WEST FLOW
ACROSS LAKE ERIE. 850MB TEMPERATURES OF -10 TO -14C WILL CONTINUE TO
MOVE ACROSS THE LAKE AVERAGING ~9C, CREATING STRONG LAKE INDUCED
INSTABILITY. THIS FLOW WILL CONTINUE TO ALLOW FOR A CONVERGENT
BOUNDARY NEAR THE LAKESHORE OF LAKE, ASHTABULA, AND ERIE PA COUNTIES
WHERE HI-RES MODELS AND RGEM SUGGEST THE TROUGH AXIS LINGERING.
MODELED SOUNDINGS CONTINUE TO SUGGEST DEEP EQL WITH STRONG LAPSE
RATES BOTH ALLOWING FOR VERY EFFICIENT SNOWFALL RATES OF 1-2"/HR TO
PERSIST. CONFIDENCE IN THIS EVENT IS VERY HIGH, THE ONLY LINGERING
QUESTION IS HOW QUICKLY THE DOMINANT BAND WILL SHIFT NORTH TODAY
WITH A BRIEF SHIFT IN WINDS TO THE SOUTHWEST. SOME HI-RES MODELS
HAVE THIS BAND LINGERING A BIT LONGER THAN PREVIOUSLY THOUGHT,
POTENTIALLY IMPACTING FAR NORTHEASTERN ERIE COUNTY THROUGH THE WHOLE
PERIOD. WITH THIS SLIGHTLY LONGER RESIDENCE TIME ON THE IMMEDIATE
LAKESHORE, ADDITIONAL SNOWFALL ACCUMULATIONS TODAY OF 10-20" IS
POSSIBLE WITH HIGHEST TOTALS ACROSS THE NORTHERN PORTION OF THE
COUNTY. ASHTABULA AND LAKE COUNTY HAVE THE POTENTIAL TO RECEIVE AN
ADDITIONAL 8-15" TODAY, AGAIN CLOSEST TO THE LAKESHORE. THIS WILL
RESULT IN CONTINUED WIDESPREAD IMPACTS AND NEARLY IMPOSSIBLE TRAVEL
CONDITIONS, ESPECIALLY ALONG I-90 AND US-20. IN ADDITION TO THE
ADDITIONAL FALLING SNOW CONCERN, WIND GUSTS OF 25-30 MPH WILL RESULT
IN PATCHY BLOWING SNOW WHICH WILL FURTHER ENHANCE THE IMPACTS,
INCLUDING QUICK REDUCTIONS IN VISIBILITIES EVEN IN AREAS WHERE IT IS
NOT ACTIVELY SNOWING. BY TONIGHT, THE DOMINANT BAND 'SHOULD' SHIFT
NORTH OVER THE LAKE AND ALLOW FOR A BRIEF REPRIEVE FROM ACCUMULATING
SNOW THROUGH SUNDAY MORNING FOR MOST AREAS. THIS IS EXPECTED TO BE
SHORT LIVED AS THE WINDS AGAIN SHIFT AND THE TROUGH AXIS SHIFTS
FURTHER SOUTH ALLOWING FOR THIS BAND TO BEGIN TO SHIFT INLAND AGAIN
SUNDAY AFTERNOON. THIS WILL RESULT IN ANOTHER PERIOD OF IMPACTFUL
LAKE EFFECT SNOWFALL FOR THE SNOWBELT. HIGH TEMPERATURES TODAY AND
TOMORROW WILL CLIMB INTO THE MID TO UPPER 20S WITH OVERNIGHT LOWS
DROPPING INTO THE TEENS. WIND CHILL VALUES OVERNIGHT WILL LIKELY
DROP INTO THE SINGLE DIGITS.
WITH A RATHER SIGNIFICANT AND IMPACTFUL EVENT ONGOING, THOUGHT
IT WOULD BE WORTH EXPLAINING THE HEADLINE DECISIONS MADE THIS
MORNING TO ENSURE WIDESPREAD UNDERSTANDING OF THE TIMING.
- CUYAHOGA COUNTY: THE WINTER WEATHER ADVISORY FOR CUYAHOGA
COUNTY HAS BEEN CANCELLED AS ANY IMPACTFUL SNOWFALL SHOULD
REMAIN EAST OF THE COUNTY. A WINTER STORM WATCH FOR LAKE
EFFECT SNOW WAS ISSUED FOR THE TIME PERIOD SPANNING SUNDAY
AFTERNOON THROUGH MONDAY EVENING TO ACCOUNT FOR THE SECOND
WAVE OF LAKE EFFECT SNOW THAT WILL IMPACT THE COUNTY.
- GEAUGA AND CRAWFORD PA COUNTIES: ONGOING LIGHT LAKE EFFECT
HAS RESULTED IN MAINTAINING THE LAKE EFFECT SNOW WARNING UNTIL
10AM, WHICH SHOULD BE LONG ENOUGH FOR THE BAND TO SHIFT NORTH
AND HOVER CLOSER TO THE LAKESHORE. UP TO 1" IN GEAUGA AND 3"
IS POSSIBLE IN CRAWFORD PA THIS MORNING. IN ADDITION, A WINTER
STORM WATCH FOR LAKE EFFECT SNOW WAS ISSUED FOR THE TIME
PERIOD SPANNING SUNDAY AFTERNOON THROUGH MONDAY EVENING TO
ACCOUNT FOR THE SECOND WAVE OF LAKE EFFECT SNOW THAT WILL
IMPACT THE COUNTY.
- ASHTABULA, LAKE, AND ERIE PA COUNTIES: THE LAKE EFFECT SNOW
WARNING HAS BEEN EXTENDED AND NOW EXPIRES AT 7AM ON TUESDAY.
OPTED TO EXTENDED THE WARNING TO ACCOUNT FOR WIDESPREAD AND
SIGNIFICANT IMPACTS THAT ARE ONGOING FROM WHAT HAS ALREADY
FALLEN. ALTHOUGH THERE MAY BE A BREAK IN SNOWFALL TONIGHT,
RECOVERY FROM ONGOING HAZARDOUS CONDITIONS COMBINED WITH THE
LIKELIHOOD OF BLOWING SNOW WILL RESULT IN CONTINUED HAZARDOUS
TRAVEL CONDITIONS AND MOTORISTS ARE ENCOURAGES TO STAY OFF THE
ROADS. THIS ESSENTIALLY MEANS THERE IS A PORTION OF THE
WARNING TIME PERIOD (TONIGHT) THAT IS PRIMARILY DRIVEN OFF OF
IMPACTS VERSUS ACCUMULATING SNOWFALL.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/
IN CASE THE FINE FOLKS OF FAR NORTHEAST OHIO AND NORTHWEST
PENNSYLVANIA HAVEN'T HAD ENOUGH SNOW YET, THE SHORT TERM PERIOD WILL
HAVE SOME MORE TO ADD ONTO THEIR GAUDY SNOW TOTALS SO FAR. ON MIDDAY
SUNDAY, THE MAIN UPPER LEVEL TROUGH AXIS WILL MOVE THROUGH THE
EASTERN GREAT LAKES REGION. THIS WILL ALLOW FOR THE LAKE EFFECT SNOW
BANDS TO ADVANCE SOUTH AGAIN BACK TOWARD THE FORECAST AREA. WITH A
MEAN WIND DIRECTION NORTH OF WEST, THERE WILL BE SOME AID FROM THE
GREAT LAKES UPSTREAM TO HELP INVIGORATE LAKE EFFECT SNOW FOR A
LARGER AREA WITHIN NORTHEAST OHIO, ESPECIALLY BACK TOWARD THE
CLEVELAND METRO AREA. THE THERMODYNAMICS FOR SUNDAY EVENING REMAIN
ADEQUATE FOR LAKE EFFECT SNOW WITH HALF INCH TO ONE INCH PER HOUR
SNOWFALL RATES WITH A BOUNDARY LAYER DEPTH AROUND 8 KFT, LAKE
INDUCED INSTABILITY AROUND 800 J/KG, AND SUFFICIENT LIFT WITHIN A
2500 FT DGZ. THE LIFT FROM THE UPPER TROUGH MOVING THROUGH THE
REGION WILL ALSO HELP WITH EFFICIENT SNOWFALL. WITH THIS PHASE OF
THE LAKE EFFECT EVENT, THERE WILL BE TWO LIMITATIONS TO TOTAL
SNOWFALL. FIRST, THE MORE NORTHWEST FLOW ACROSS THE REGION WILL USE
A SHORTER FETCH OVER LAKE ERIE AND LIMIT THE TOTAL PARCEL RESIDENCE
TIME OVER THE LAKE FOR BUILDING MORE EFFICIENT SNOWFALL. THE OTHER
CONCERN IS THAT THE NORTHWEST FLOW WILL HAVE LESS MOISTURE DEPTH AND
BE MORE DEPENDENT ON THE UPSTREAM LAKE COMPONENT. REGARDLESS, THERE
IS CONFIDENCE AT THIS TIME TO HAVE A RIBBON OF 6 TO 12 INCHES OF
SNOW FOR NORTHEAST CUYAHOGA COUNTY THROUGH ERIE COUNTY PA FOR SUNDAY
THROUGH MONDAY EVENING. SOME OF THE LAKE EFFECT WARNINGS HAVE BEEN
EXTENDED TO INCORPORATE THIS TIME FRAME, WHILE NEW WINTER STORM
WATCHES HAVE BEEN POSTED FOR AREAS WHERE THE SNOW WILL BE ENDING
THIS MORNING BUT RETURN ON SUNDAY. THERE WILL BE ISSUES FOR THE
MONDAY MORNING COMMUTE IN THIS REGION.
ANOTHER SHORTWAVE WILL MOVE THROUGH MONDAY AFTERNOON AND DRY AIR AND
SOME SUBSIDENCE WILL START TO ENTER FOR MONDAY NIGHT. HIGH PRESSURE
WILL STRENGTHEN OVER THE OHIO VALLEY ON TUESDAY AND FLOW WILL BACK
ACROSS THE REGION. THIS WILL END THE LAKE EFFECT SNOW EVENT AND
ALLOW FOR JUST SOME SCATTERED SNOW SHOWERS ON TUESDAY WITH MINIMAL
IMPACT. TEMPERATURES WILL REMAIN BELOW NORMAL FOR THE PERIOD WITH
HIGHS IN THE 30S AND LOWS IN THE 20S.
LONG TERM /WEDNESDAY THROUGH FRIDAY/
AN ACTIVE PATTERN RESUMES ON WEDNESDAY AS A NEW UPPER TROUGH WILL
DIG INTO THE GREAT LAKES REGION AND A SURFACE LOW PRESSURE SYSTEM
WILL MOVE THROUGH THE NORTHERN LAKES INTO CANADA. THIS SYSTEM
APPEARS TO BRING WIDESPREAD SNOWFALL ALONG WITH SOME GUSTY WINDS TO
THE REGION. BEHIND THE SYSTEM, ANOTHER COLD AIR MASS WILL SETTLE
INTO THE AREA AND BRING BELOW NORMAL TEMPERATURES AND LIKELY SOME
MORE LAKE EFFECT SNOW. WHILE DETAILS ARE TOO EARLY TO PROCESS, IT
APPEARS THAT FLOW WILL FAVOR A NORTHWEST DIRECTION, WHICH WOULD
ALLOW FOR A WIDER AREA OF THE NE OH/NW PA SNOW BELT TO GET INVOLVED
WITH SNOW. SOMETHING TO STAY TUNED ABOUT FOR THE END OF THE
WEEK...
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AS A SURFACE TROUGH PERSISTS OVER THE AREA THROUGH THIS TAF
PERIOD, MUCH OF THE AREA WILL REMAIN CLOUDY WITH CEILINGS 5KFT
OR HIGHER. THE EXCEPTION TO THIS IS ACROSS THE SNOWBELT WHERE
HEAVY LAKE EFFECT SNOW IS EXPECTED TO CONTINUE THROUGH THE
DURATION OF THIS PERIOD. EXPECT KERI TO MAINTAIN IFR TO LIFR
CONDITIONS THROUGH AT LEAST THIS AFTERNOON AS A HEAVY BAND OF
SNOW HUGS THE SHORELINE. BY THIS AFTERNOON/EVENING, SOME HI-RES
MODEL GUIDANCE SUGGESTS THAT THE HEAVIEST PART OF THE BAND WILL
SHIFT NORTH OVER LAKE ERIE, POTENTIALLY ALLOWING FOR A REPRIEVE
OF SNOWFALL AT THE TERMINAL. WILL HAVE TO CONTINUE TO MONITOR,
BUT OPTED FOR A PROB30 TO END THE TAF WITH A GOOD BIT OF
UNCERTAINTY REMAINING ABOUT THE MOVEMENT.
GUSTY WINDS OF 12-15 KNOTS, GUSTING UP TO 25 KNOTS WILL PERSIST
AT ALL TERMINALS THROUGH THIS EVENING, ALTHOUGH THERE WILL
LIKELY BE A BRIEF LULL IN WIND SPEEDS EARLY THIS MORNING FOR
TERMINALS ACROSS THE SOUTHERN TIER OF COUNTIES. LOCALLY HIGHER
GUSTS ARE POSSIBLE ALONG THE LAKESHORE. THESE GUSTS HAVE THE
POTENTIAL TO RESULT IN BLOWING SNOW AT KERI WHICH WOULD ACT TO
FURTHER REDUCE VISIBILITIES EVEN IF SNOW IS NOT ACTIVELY
FALLING. BY 00Z SUNDAY, WINDS AT ALL TERMINALS WILL REDUCE TO
5-10 KNOTS, AGAIN WITH THE EXCEPTION OF KERI WHICH WILL REMAIN
ELEVATED THROUGH THE ENTIRE PERIOD.
OUTLOOK...NON-VFR LIKELY IN PERIODIC LAKE-EFFECT SNOW 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
A LAKE AGGREGATE TROUGH WITH A STRONG LAKE EFFECT SNOW BAND HAS
SETUP ACROSS LAKE ERIE AND STRONG GENERALLY WESTERLY WINDS HAVE SET
UP OVER THE LAKE. THERE HAS BEEN SOME BACKED FLOW ALONG THE
IMMEDIATE LAKESHORE WITH SOME WINDS BELOW 20 KT IN THE CENTRAL
BASIN. HOWEVER, WINDS WILL CONTINUE TO REMAIN ELEVATED AROUND 20 KT
AND WAVES WILL BE 4 FT OR GREATER EAST OF THE LAKE ERIE ISLANDS.
HIGH PRESSURE WILL BUILD FROM THE SOUTH FOR TUESDAY AND REDUCE FLOW,
BUT HIGHER WAVES SHOULD PERSIST FOR THE CENTRAL BASIN. THE NEXT
SYSTEM WILL ENTER THE GREAT LAKES REGION FOR WEDNESDAY AND THERE
WILL BE A STRONG UPTICK IN WINDS WITH SOUTHWEST FLOW. THERE IS A NON-
ZERO CHANCE FOR GALES WITH THIS SETUP. FOR THIS MORNING'S PACKAGE,
HAVE REDISTRIBUTED THE WEATHER HEADLINES A BIT. THE WESTERLY FLOW
WILL REMAIN ELEVATED OVER THE WESTERN BASIN, WHICH WILL ALLOW FOR
THE WATER LEVELS TO DROP AGAIN THIS AFTERNOON TOWARD THE CRITICAL
MARK. THEREFORE, HAVE EXTENDED BOTH THE SMALL CRAFT ADVISORY AND LOW
WATER ADVISORY TO 10 PM TONIGHT. FOR THE ISLANDS TO VERMILION ZONE,
BELIEVE THAT THE FORECAST IS LESS SEVERE FOR SMALL CRAFT CONDITIONS
ON SUNDAY AND HAVE ADDED THAT ZONE TO THE WESTERN BASIN GROUPING
ENDING AT 10 PM TONIGHT. FOR VERMILION AND EAST, THE SMALL CRAFT
ADVISORY CONDITIONS WILL REMAIN SEMI-PERMANENT THIS WEEK AND HAVE
GONE AHEAD AND ADDED TWO DAYS TO THE HEADLINE WITH A NEW ENDING TIME
OF 7 AM WEDNESDAY. HOWEVER, THIS END TIME DOESN'T REFLECT THE END OF
SMALL CRAFT ADVISORY CONDITIONS, AS CONDITIONS WILL WORSEN ON
WEDNESDAY AND THERE IS A NON-ZERO GALE WARNING CHANCE.
CLE WATCHES/WARNINGS/ADVISORIES
OH...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR OHZ011-013.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR OHZ012-014-
089.
LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR
OHZ013.
PA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR PAZ003.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR PAZ001-002.
LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR
PAZ003.
MARINE...LOW WATER ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ142>144-
162>164.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LEZ142>144.
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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