050
FXUS61 KCLE 282106
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
406 PM EST THU NOV 28 2024
SYNOPSIS
A BROAD UPPER LEVEL LOW SETTLES INTO THE GREAT LAKES FOR THE
FORESEEABLE FUTURE. ONSHORE WINDS WILL MAKE FOR A PROLONGED
LAKE EFFECT SNOW EVENT BEGINNING TONIGHT THROUGH THE WEEKEND,
POSSIBLY LASTING INTO .
NEAR TERM /THROUGH FRIDAY NIGHT/
THE CALM BEFORE THE LAKE EFFECT SNOW STORM IS NOW UPON US. THE
WEATHER WILL QUICKLY GO DOWNHILL OVERNIGHT TONIGHT FOR OUR
PRIMARY SNOWBELT OF NEOH AND NWPA FOR WHAT LOOKS A PROLONGED
LAKE EFFECT SNOW EVENT OVER SEVERAL DAYS. A LARGE CYCLONIC FLOW
IS DEVELOPING OVER THE GREAT LAKES REGION WITH THE CENTER
HOLDING STATIONARY NEAR THE SOUTHERN TIP OF HUDSON BAY. THIS
WEATHER SETUP WILL BE THE MAIN PLAYER OVER THE NEXT 36 HOURS AND
LONGER.
THE LOW LEVEL FLOW HAS BECOME WEST-NORTHWESTERLY WITH THE MEAN
FLOW ABOUT 290 DEGREES AT THIS TIME AND SHOULD CONTINUE THROUGH
THE LATE EVENING HOURS. COLDER AIR ALOFT IS JUST NOW STARTING TO
ADVECT IN THROUGH THE LOWER AIR COLUMN. 850MB TEMPS RIGHT NOW
ARE AVERAGING ABOUT -6C. THE LAKE TEMPERATURE IS AVERAGING
ABOUT 50F OR 10C. IN THE LAST COUPLE OF HOURS, SCATTERED LAKE
EFFECT RAIN SHOWERS MIXED WITH WET SNOW AND GRAUPEL HAVE
DEVELOPED ACROSS NEOH AND NWPA. THIS LAKE EFFECT IS JUST THE
BEGINNING STAGES OF WHAT IS TO COME STARTING LATER THIS EVENING.
AS WE HEAD INTO THE LATER EVENING HOURS, BASICALLY ALL THE
HIGH-RES MODEL GUIDANCE SHOWS A BAND OF LAKE EFFECT SNOW WITH A
LAKE MICHIGAN CONNECTION DEVELOPING ACROSS WESTERN LAKE ERIE
COMING INTO THE NORTH COAST OF NEOH AND AROUND THE CLEVELAND
METRO AREA ON A WEST-NORTHWESTERLY FLOW. 850 MB TEMPS WILL TO
AROUND -10C OVERNIGHT. LAKE INDUCE CAPE VALUES WILL REACH
SEVERAL HUNDRED JULES LATER TONIGHT. WE EXPECT THIS LAKE EFFECT
SNOW BAND TO BECOME BETTER ORGANIZED BY EARLY FRIDAY MORNING AS
IT SHIFTS SLIGHTLY NORTHWARD INTO PORTIONS OF NORTHEAST
CUYAHOGA, LAKE, NORTHERN GEAUGA, ASHTABULA COUNTIES AND PORTIONS
OF NWPA BETWEEN 06Z AND 12Z. ELSEWHERE TONIGHT, A FEW SCATTERED
LIGHT SNOW SHOWERS OR FLURRIES COULD BE POSSIBLE BUT THE
ACCUMULATING AND IMPACTFUL WINTER WEATHER WILL BE CONFINED TO
THE PRIMARY SNOWBELT REGION.
BY FRIDAY MORNING, THERE WILL BE AN ORGANIZED LAKE EFFECT SNOW
BAND WITH A LAKE MICHIGAN CONNECTION HITTING OUR FAR NEOH AND
NWPA SNOWBELT. SNOWFALL RATES WILL LIKELY BE 1 TO 2 INCHES
PER HOUR WITH POTENTIALLY UP TO 3 INCHES PER HOUR POSSIBLE
UNDERNEATH THE HEAVIEST SQUALLS. WE HAVE ADDED THE SLIGHT
MENTION OF THUNDERSNOW WHERE THIS LES BAND IS MOST INTENSE
STARTING 09Z FRIDAY MORNING AND CONTINUE THAT POTENTIAL THROUGH
FRIDAY NIGHT. 850 MB TEMPS WILL FALL TO AROUND -12C ON FRIDAY
WITH A DELTA T OF OVER 20 DEGREES CELSIUS. CAPE VALUES FROM
LAKE INDUCED ENERGY WILL BE UPWARDS OF 400 J/KG. THE LOW LEVEL
FLOW MAY BACK A LITTLE DURING THE FRIDAY WHICH WILL NUDGE THE
BAND SLIGHTLY NORTHWARD TO IMPACT MORE OF THE LAKESHORE AREAS OF
NWPA AND AROUND THE ERI AREA. WE MAY SEE THIS ORGANIZED BAND
WAFFLE A LITTLE BIT NORTH AND SOUTH LATE FRIDAY AFTERNOON INTO
THE EVENING BEFORE IT REPOSITION ITSELF INTO THE FAR NEOH CORNER
AND NWPA INTO FRIDAY NIGHT. SNOW RATIOS WILL START OFF THURSDAY
NIGHT LOWER AT 12:1 BUT INCREASE TO 18:1 BY FRIDAY NIGHT.
SNOWFALL TOTALS FOR THE NEXT 36 HOURS THROUGH 12Z SATURDAY IN
THE SNOWBELT OF FAR NEOH AND NWPA WILL BETWEEN 6 AND 18 INCHES,
THAT IS FOR THE LAKE EFFECT SNOW WARNING AREA. THERE IS THE
POTENTIAL THAT SOMEWHERE IN NORTHERN ASHTABULA AND PARTS OF
NWPA MAY SEE UP TO 2 FEET OF SNOW BY LATE FRIDAY NIGHT INTO
EARLY SATURDAY MORNING. OUTSIDE THE WARNING AND ADVISORY AREA,
LITTLE TO NO SNOWFALL ACCUMULATION IS EXPECTED.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
THE EARLY SEASON COLD SNAP WILL CONTINUE THROUGH THE WEEKEND, WITH
TEMPERATURES AVERAGING 10-15 DEGREES BELOW NORMAL, BUT THE BIG STORY
WILL REMAIN ONGOING LAKE-EFFECT SNOW.
IN TERMS OF THE SYNOPTIC PATTERN, DEEP MID/UPPER LONGWAVE TROUGHING
WILL CONTINUE ACROSS CENTRAL AND EASTERN NORTH AMERICA DOWNSTREAM OF
A STRONG RIDGE ALONG THE US AND CANADIAN WEST COASTS. THE ASSOCIATED
CLOSED MID-LEVEL LOW WILL INITIALLY BE CENTERED OVER JAMES BAY, BUT
IT WILL START TO DRIFT EASTWARD TOWARD LABRADOR BY SUNDAY. THIS WILL
MAINTAIN A BROAD CYCLONIC FLOW OF COLD AIR ACROSS THE ENTIRE GREAT
LAKES REGION, WITH PERIODIC SHORTWAVES ROTATING THROUGH THE FLOW TO
ENHANCE THE SYNOPTIC MOISTURE AND LIFT, AS WELL AS SLIGHTLY
ALTER THE BOUNDARY LAYER WIND FIELDS. THIS IS A CLASSIC PATTERN
FOR A LONG RANGE LAKE-EFFECT SNOW EVENT DOWNWIND OF LAKE ERIE.
IN FACT, THIS MAY BE THE LONGEST DURATION LAKE-EFFECT SNOW EVENT
IN OUR CWA SINCE LATE DECEMBER 2017. SNOW AMOUNTS WILL ADD UP
TO VERY IMPRESSIVE TOTALS IN LOCATIONS WHERE THE BANDS PERSIST
THE LONGEST, BUT EXACTLY WHERE THOSE LOCATIONS ARE REMAINS THE
BIGGEST UNCERTAINTY. PLEASE FOCUS ON IMPACTS INSTEAD OF TOTAL
SNOW AMOUNTS SINCE THE SNOW WILL BE LOCALLY HEAVY AT TIMES, WITH
RATES OF 1-3 INCHES PER HOUR. THIS WILL LEAD TO PERIODS OF VERY
POOR VISIBILITY AND EXTREMELY DIFFICULT TRAVEL.
IN TERMS OF DETAILS, A BAND OF SNOW SHOULD STILL BE IMPACTING AT
LEAST NORTHERN ERIE COUNTY, PA, INCLUDING DOWNTOWN ERIE, SATURDAY
MORNING. THIS BAND COULD STILL BE INTENSE WITH RATES OF 1-3 INCHES
PER HOUR AS NAM BUFKIT SOUNDINGS SUGGEST ABUNDANT OMEGA (LIFT) AND
SATURATION WITHIN THE DGZ ALONG WITH MODERATE TO EXTREME INSTABILITY
AS 850 MB TEMPS FALL TO -12 C, WITH EQUILIBRIUM LEVELS AVERAGING 10-
12 THOUSAND FEET. THIS IS ALL IN SPITE OF INCREASING SHEAR, SO STILL
EXPECT IMPACTFUL SNOW. CONFIDENCE IS HIGH THAT BY SATURDAY
AFTERNOON, BOUNDARY LAYER FLOW BACKING TO ABOUT 250 DEGREES WILL
LIFT THE BAND MAINLY OFFSHORE TO AFFECT MAINLY THE WESTERN SOUTHERN
TIER OF NEW YORK. IT WILL LIKELY CLIP NE ERIE COUNTY THROUGH THE
AFTERNOON, BUT CONDITIONS WILL BE IMPROVING. THE BAND WILL BE
SOLIDLY OFFSHORE AT LEAST THE FIRST HALF OF SATURDAY NIGHT BEFORE IT
BEGINS TO PUSH BACK SOUTHWARD AS A SHORTWAVE CROSSES THE REGION AND
STARTS VEERING THE FLOW MORE TOWARD 260-270 DEGREES. THERE IS
UNCERTAINTY WITH HOW FAST THE BAND MOVES BACK SOUTHWARD. THE LAST
COUPLE RUNS OF THE RGEM HAVE KEPT IT FARTHER NORTH, AND THIS VERY
WELL MAY BE THE CASE SINCE THE LAKE AGGREGATE THERMAL TROUGH WILL BE
WELL IN PLAY BY THIS TIME, CAUSING WINDS TO POSSIBLY BE BACKED 10 OR
MORE DEGREES. DUE TO THE UNCERTAINTY, VERY GRADUALLY BROUGHT HIGHER
POPS BACK INTO EXTREME NE OHIO AND NW PA SATURDAY NIGHT.
SUNDAY AND SUNDAY NIGHT WILL BE THE START OF THE MORE WIDESPREAD
IMPACTS FOR OUR PRIMARY SNOWBELT EAST OF CLEVELAND AND THROUGH NW
PA. A STRONGER SHORTWAVE WILL PUSH ACROSS THE REGION IN THE
AFTERNOON, AND THE ASSOCIATED SURFACE TROUGH WILL PUSH THE BAND
INLAND AS WINDS VEER FROM ABOUT 260-270 TO ABOUT 280-300 DEGREES.
THIS WILL LEAD TO A BURST OF SNOW IN MOST AREAS, INCLUDING THE
CLEVELAND METRO AREA AND MAYBE AS FAR SOUTH AS NORTHERN MEDINA,
SUMMIT, PORTAGE, AND TRUMBULL COUNTIES, SO HAVE EXPANDING POPS
SUNDAY AFTERNOON. AGAIN, EXACT TIMING AND HOW FAST THE BAND PUSHES
INLAND IS UNCERTAIN SINCE LOW-LEVEL WINDS HAVE BEEN TRENDING A
LITTLE MORE WESTERLY AS OPPOSED TO PURELY WNW, BUT THE IDEA IS FOR
SNOW GRADUALLY PUSHING INTO MORE OF THE OHIO COUNTIES. CONTINUED
MODERATE TO EXTREME LAKE INDUCED INSTABILITY, GREAT SYNOPTIC
MOISTURE, AND LIFT FROM THE SHORTWAVE WILL LEAD TO INTENSE SNOWFALL
RATES OF 1-2 INCHES PER HOUR AT TIMES, SO IMPACTS WILL BE
SIGNIFICANT. LAKE-EFFECT SNOW SQUALLS WILL CONTINUE THROUGH SUNDAY
NIGHT AS THE BANDS BECOME REORGANIZED ON MORE OF A W TO WNW FLOW
(ABOUT 280-300 DEGREES). THIS WILL KEEP MODERATE TO HEAVY AREAS OF
SNOW OVER THE PRIMARY SNOWBELT, ALTHOUGH A BAND WITH AN UPSTREAM
CONNECTION TO LAKE MICHIGAN OR LAKE SAINT CLAIR COULD CROSS THE LAKE
ERIE ISLANDS AND IMPACT LORAIN, WESTERN/SOUTHERN CUYAHOGA, MEDINA,
AND SUMMIT COUNTIES AT TIMES. WE HAVE SEEN THIS BAND MANY TIMES
BEFORE IF THE FLOW ENDS UP WNW, SO INCLUDED A WIDE AREA OF AT LEAST
CHANCE POPS.
SNOWFALL AMOUNTS THROUGH SUNDAY NIGHT WILL BE HIGHEST ALONG THE I-90
CORRIDOR FROM LAKE COUNTY TO ERIE, PA, WHERE ADDITIONAL AMOUNTS OVER
12 INCHES ARE POSSIBLE, WITH THE BULK COMING SATURDAY NIGHT THROUGH
SUNDAY NIGHT. ACROSS THE REST OF THE SNOWBELT AND CLEVELAND AREA,
AMOUNTS ARE MORE UNCERTAIN, BUT MANY AREAS COULD PICK UP 3 TO 6
INCHES LATER SUNDAY AND SUNDAY NIGHT AS THE BANDS SLOWLY PRESS
INLAND, WITH LOCALLY OVER 8 INCHES. ADDITIONAL WINTER WEATHER
HEADLINES ARE LIKELY LATE SATURDAY NIGHT INTO EARLY NEXT WEEK.
HIGHS SATURDAY AND SUNDAY WILL STAY IN THE UPPER 20S/LOW 30S AS THE
COLDEST AIR OF THE SEASON SO FAR MOVES IN, WITH LOWS IN THE MID
TEENS TO LOW 20S BOTH SATURDAY AND SUNDAY NIGHTS. COLDEST WELL
INLAND OF THE LAKE.
LONG TERM /MONDAY THROUGH THURSDAY/
LAKE-EFFECT SNOWS WILL CONTINUE THROUGH AT LEAST TUESDAY NIGHT AS
THE DEEP MID/UPPER LONGWAVE TROUGH AXIS GRADUALLY SHIFTS INTO THE
EASTERN GREAT LAKES ALLOWING A LARGE SURFACE HIGH TO SLIDE TOWARD
THE TENNESSEE VALLEY. THIS WILL CAUSE BROAD WNW FLOW TO PERSIST,
WITH CONTINUED SHORTWAVE DISTURBANCES CROSSING THE REGION TO ENHANCE
LIFT AND SYNOPTIC MOISTURE. KEPT AT LEAST LIKELY POPS IN THE PRIMARY
SNOWBELT OF NE OHIO AND NW PA, WITH CHANCE ELSEWHERE. IMPOSSIBLE TO
PINPOINT BAND LOCATION AT THIS TIME, BUT SIGNIFICANT AMOUNTS WILL
CONTINUE WHERE BANDS PERSIST. BY WEDNESDAY, BACKING FLOW AND SOME
WEAK WARM AIR ADVECTION SHOULD TRY TO END THE LAKE-EFFECT, BUT A
FAST MOVING CLIPPER SYSTEM APPROACHING WEDNESDAY NIGHT WILL BRING
RAIN/SNOW BACK TO THE REGION IN THE WEDNESDAY NIGHT OR THURSDAY TIME
PERIOD, SO NO DRY PERIODS WERE INCLUDED IN THE EXTENDED. THE PRECIP
WITH THE CLIPPER WILL BE MORE WIDESPREAD, BUT TOO FAR OUT TO KNOW
SPECIFICS.
HIGHS IN THE UPPER 20S AND LOW 30S MONDAY AND TUESDAY WILL MODERATE
INTO THE MID 30S WEDNESDAY AND UPPER 30S TO AROUND 40 THURSDAY.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
CONDITIONS RANGE FROM IFR AROUND MFR TO VFR CEILINGS IN NWOH
WITH EVERYONE ELSE IN BETWEEN. CONDITIONS WILL CONTINUE TO VARY
THIS AFTERNOON WITH MOSTLY MVFR CEILINGS TO VFR CEILINGS
EXPECTED INTO THE EARLY EVENING. THERE ARE SOME LINGERING LAKE
EFFECT RAIN/SNOW SHOWERS CONTINUING OVER NEOH THIS AFTERNOON.
THE WEATHER WILL START TO BECOME MORE IMPACTFUL FOR AVIATION
INTEREST STARTING THIS EVENING THROUGH FRIDAY IN THE PRIMARY
SNOWBELT OF NEOH AND NWPA. SCATTERED LAKE EFFECT SNOW SHOWERS
AND SQUALLS WILL START DEVELOPING LATER THIS EVENING BETWEEN 00Z
AND 06Z ACROSS NEOH AND NWPA. THESE SNOW SHOWERS MAY IMPACT CLE,
CAK, AND YNG THIS EVENING WITH MVFR TO BRIEF IFR CONDITIONS.
OVERNIGHT INTO FRIDAY MORNING, WE EXPECT THE LAKE EFFECT SNOW TO
BECOME MORE ORGANIZED IN A BAND MAINLY IMPACTING THE FAR CORNER
OF NEOH AND NWPA THROUGH THE END OF THE TAF PERIOD WITH IFR TO
LIFR CONDITIONS UNDERNEATH THE HEAVIER SQUALLS. THIS SNOW BAND
MAY IMPACT ERI LATE OVERNIGHT THROUGH MIDDAY FRIDAY. THERE ALSO
COULD BE SOME THUNDERSNOW ASSOCIATED WITH IT. AS FOR THE REST
OF THE TAF SITES ACROSS CENTRAL AND NWOH, WE ARE EXPECTED MAINLY
MVFR CEILINGS AND MAYBE A FEW PASSING LIGHT SNOW SHOWERS. WINDS
WILL BECOME WEST-NORTHWESTERLY THIS AFTERNOON AND OVERNIGHT 8
TO 12 KNOTS WITH OCCASIONAL GUSTS UP TO 20 KNOTS POSSIBLE.
WINDS WILL INCREASE FROM THE WEST FRIDAY MORNING 12 TO 16 KNOTS
WITH GUSTS LIKELY UP TO 25 KNOTS.
OUTLOOK...NON-VFR LIKELY IN PERIODIC LAKE-EFFECT SNOW IS
EXPECTED FRIDAY THROUGH MONDAY. 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
NW WINDS THIS EVENING WILL TURN W TONIGHT THROUGH FRIDAY AND
INCREASE TO 15-25 KNOTS, WITH UP TO 30 KNOTS AT TIMES. THIS WILL
CAUSE A LONG PERIOD OF SMALL CRAFT ADVISORY CONDITIONS THROUGH EARLY
NEXT WEEK. THE W WINDS OF 15-25 KNOTS FRIDAY WILL TURN WSW BY
SATURDAY AND SATURDAY NIGHT BEFORE TURNING W AGAIN SUNDAY, THEN WNW
SUNDAY NIGHT THROUGH TUESDAY, BUT SPEEDS WILL REMAIN IN THE 15-25
KNOT RANGE AND OCCASIONALLY UP TO 30 KNOTS. RAN THE SMALL CRAFT
ADVISORIES THROUGH MONDAY MORNING FOR THE CENTRAL AND EASTERN
BASINS, BUT THEY WILL LIKELY NEED TO BE EXTENDED. OTHERWISE, THE
STRONGER W WINDS WILL INITIALLY CAUSE LOW WATER IN THE WESTERN BASIN
FRIDAY INTO SATURDAY. IT'S POSSIBLE THAT THE LEVELS WILL IMPROVE
FASTER SATURDAY MORNING, BUT ISSUED THE ADVISORY THROUGH 18Z
SATURDAY BASED ON PATTERN RECOGNITION OF LONG DURATION W TO WSW
FLOW.
CLE WATCHES/WARNINGS/ADVISORIES
OH...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
SATURDAY FOR OHZ011.
LAKE EFFECT SNOW WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST
SATURDAY FOR OHZ012>014-089.
PA...LAKE EFFECT SNOW WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST
SATURDAY FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LEZ144>149.
SYNOPSIS...GRIFFIN
NEAR TERM...GRIFFIN
SHORT TERM...GARUCKAS
LONG TERM...GARUCKAS
AVIATION...GRIFFIN
MARINE...GARUCKAS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page