424
FXUS61 KCLE 172017
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
305 PM EST SAT JAN 17 2026
WHAT HAS CHANGED
FORECAST CONFIDENCE CONTINUES TO INCREASE THAT LAKE-EFFECT SNOW
WILL DEVELOP DOWNWIND OF LAKE ERIE TONIGHT, BECOME SIGNIFICANT
AND OSCILLATE ON SUNDAY THROUGH AT LEAST TUESDAY, AND PRIMARILY
IMPACT PORTIONS OF WESTERN NY. HOWEVER, WHAT REMAINS MUCH MORE
UNCERTAIN IS WHETHER THE LAKE-EFFECT SNOW WILL SHIFT INTO
NORTHWEST PA AND FAR-NORTHEAST OH FOR A RELATIVELY PROLONGED
PERIOD OF TIME AND YIELD AT LEAST ADVISORY-CRITERIA SNOW
ACCUMULATIONS. THIS UNCERTAINTY PRECLUDED THE ISSUANCE OF A
WINTER STORM WATCH FOR ANY OF OUR SNOWBELT COUNTIES WITH THIS
FORECAST UPDATE.
KEY MESSAGES
1) A LINEAR SNOW SQUALL AND TRAILING LIGHTER SNOW SHOWERS ALONG
AN E'WARD-MOVING COLD FRONT EXIT NE OH AND NW PA BY THIS LATE
AFTERNOON.
2) PRIMARILY BELOW-NORMAL TEMPERATURES ARE EXPECTED TONIGHT
THROUGH THE UPCOMING WEEK.
3) LAKE-EFFECT SNOW DEVELOPS DOWNWIND OF LAKE ERIE TONIGHT AND
PERSISTS THROUGH AT LEAST THE MIDDLE OF THE UPCOMING WEEK.
4) OUTSIDE THE LAKE-EFFECT SNOW, PERIODIC, WIDESPREAD, AND
ACCUMULATING SNOW SHOULD IMPACT OUR REGION THROUGH THE UPCOMING
WEEK.
DISCUSSION
KEY MESSAGE 1...
AT 1:40 PM EST THIS AFTERNOON, A SURFACE COLD FRONT WAS LOCATED
NEAR AN ERIE, PA TO WARREN, OH TO MINERVA, OH LINE. THIS FRONT
WILL CONTINUE MOVING E'WARD AND IS EXPECTED TO EXIT THE REST OF
OUR CWA BY 4 PM, GIVE OR TAKE ONE HOUR. CONVERGENCE/MOIST
ASCENT ALONG THE SURFACE COLD FRONT WILL CONTINUE TO RELEASE
WEAK POTENTIAL INSTABILITY IN THE LOWEST ~1 KM AGL AND RESULT IN
STRONG/MAXIMIZED ASCENT AT A CLOUD TEMPERATURE NEAR -8C TO -10C
BELOW CLOUD TOP TEMPERATURES IN THE DGZ AND AS SURFACE WET-BULB
TEMPERATURES HOVER NEAR 0C AHEAD OF THE FRONT. THUS, STEADY TO
HEAVY SNOW AND GRAUPEL SHOWERS WILL PERSIST ALONG THE SURFACE
FRONT IN OUR CWA AND CONTINUE TO PROMPT SPECIAL WEATHER
STATEMENTS OR SNOW SQUALL WARNINGS. LIGHT SNOW SHOWERS RELATED
TO MOIST ISENTROPIC ASCENT ALOFT REMAIN POSSIBLE AHEAD OF THE
FRONT, WHILE LIGHT SNOW SHOWERS ARE ALSO POSSIBLE FOR UP TO
ABOUT TWO HOURS BEHIND THE SURFACE COLD FRONT PASSAGE AND WILL
BE ASSOCIATED WITH CONVERGENCE/MOIST ASCENT ALONG THE UPPER-
REACHES OF THE FRONT. FRESH SNOW ACCUMULATIONS TODAY ARE
EXPECTED TO BE 2" OR LESS. GREATEST AMOUNTS ARE EXPECTED IN THE
HIGHER TERRAIN OF NW PA, WHERE A SOMEWHAT COLDER ENVIRONMENT
SHOULD ALLOW SNOW TO ACCUMULATE MORE EASILY.
KEY MESSAGE 2...
BEHIND TODAY'S COLD FRONT PASSAGE, PRIMARILY BELOW-NORMAL
TEMPERATURES ARE EXPECTED TONIGHT THROUGH SATURDAY, JANUARY 24TH
A NET AND DEEP TROUGHING ALOFT, ASSOCIATED WITH AN UNUSUALLY-
COLD AIR MASS, BECOMES ESTABLISHED OVER EASTERN CANADA AND
IMPACTS THE EASTERN UNITED STATES DURING THE BULK OF THE NEXT
SEVEN DAYS. AT THE SURFACE, OUR CWA IS EXPECTED TO PRIMARILY
RESIDE IN THE COLD SECTOR BASED ON THE LATEST PROJECTED MID
LATITUDE CYCLONE TRACK. A REINFORCING ARCTIC FRONT SHOULD SWEEP
E'WARD THROUGH OUR REGION ON MONDAY BEFORE A WARM FRONT SWEEPS
NE'WARD THROUGH OUR REGION TUESDAY NIGHT. PRIOR TO THE WARM
FRONT PASSAGE, OVERNIGHT LOWS ARE EXPECTED TO BE NEAR 10F TO 15F
AROUND DAYBREAK SUNDAY AND MONDAY, RESPECTIVELY, NEAR 0F TO 5F
AROUND DAYBREAK TUESDAY, AND BOTTOM-OUT NEAR 5F TO 10F TUESDAY
EVENING, BEFORE THE WARM FRONT USHERS-IN A WARMER AIR MASS
ORIGINATING OVER THE GULF. MINIMUM WIND CHILLS SHOULD BE MAINLY
IN THE 0F TO -10F RANGE TONIGHT THROUGH TUESDAY NIGHT, BUT THE
COLDEST MINIMUM WIND CHILLS (-10F TO -20F) ARE EXPECTED AROUND
DAYBREAK TUESDAY AND SHOULD EVENTUALLY PROMPT THE ISSUANCE OF A COLD
WEATHER ADVISORY. AS FOR DAILY DAYTIME HIGH TEMPERATURES, THOSE
SHOULD REACH THE 15F TO 25F RANGE SUNDAY AND MONDAY RESPECTIVELY,
AND ONLY THE 10F TO 20F RANGE TUESDAY.
ON WEDNESDAY, LOW-LEVEL WAA IN THE WARM SECTOR SHOULD CONTRIBUTE
TO HIGHS REACHING THE LOWER TO MID 30'S BEFORE A STRONG COLD
FRONT SWEEPS SE'WARD ACROSS OUR CWA WEDNESDAY AFTERNOON AND
EVENING. NET LOW-LEVEL CAA BEHIND THE FRONT IS EXPECTED THROUGH
THE END OF NEXT WEEK AND CONTRIBUTE TO BELOW-NORMAL TEMPERATURES
WEDNESDAY NIGHT THROUGH SATURDAY, JANUARY 24TH. ADDITIONAL SUB-
ZERO WIND CHILLS ARE POSSIBLE, ESPECIALLY AROUND DAYBREAK
FRIDAY.
KEY MESSAGE 3...
LAKE-EFFECT SNOW (LES) SHOULD DEVELOP OVER AND DOWNWIND OF THE
~1C ICE-FREE WATERS OF LAKE ERIE TONIGHT, ESPECIALLY AFTER
MIDNIGHT, AS 850 MB TEMPERATURES TUMBLE TO NEAR -16C BEHIND THE
COLD FRONT. HOWEVER, THE LES IS EXPECTED TO BE LIGHT, DUE IN
PART TO LIMITED MOISTURE BETWEEN 850 AND 700 MB, AND PRIMARILY
IMPACT PORTIONS OF WESTERN NY DUE TO A SW'ERLY MEAN LOW-LEVEL
FLOW. HOWEVER, THESE LIGHT LES SHOWERS MAY SKIRT THE LAKESHORE
AT TIMES IN OUR CWA, EAST OF CLEVELAND, AND YIELD SNOW
ACCUMULATIONS LESS THAN ONE INCH.
DURING THE DAYLIGHT HOURS OF SUNDAY THROUGH THE DAYLIGHT HOURS
OF TUESDAY, THE MEAN LOW-LEVEL FLOW OF SUFFICIENTLY-COLD/MOIST
AIR OVER THE RELATIVELY-WARM, ICE-FREE LAKE WATERS SHOULD VARY
BETWEEN MAINLY SW'ERLY AND WSW'ERLY AS MULTIPLE SHORTWAVE
TROUGHS TRAVERSE THE LAKE ERIE REGION GENERALLY FROM WEST TO
EAST, 850 MB TEMPERATURES WAVER BETWEEN -15C AND -22C AMIDST
GREATER/DEEPER LOW-LEVEL MOISTURE, WHICH WILL YIELD GREATER
LAKE-INDUCED INSTABILITY AND LIKELY YIELD A STRONG LAKE-INDUCED
THERMAL SURFACE TROUGH OVER THE ICE-FREE LAKE WATERS, WHICH
SHOULD KEEP THE MEAN LOW-LEVEL FLOW AT LEAST SOMEWHAT BACKED.
THUS, STEADIER TO HEAVY LES IS EXPECTED TO PRIMARILY IMPACT
PORTIONS OF WESTERN NY DURING THE AFOREMENTIONED TIME PERIOD.
HOWEVER, DURING MONDAY THROUGH MONDAY EVENING, THE ABOVE-
MENTIONED ARCTIC FRONT PASSAGE AND ATTENDANT SHORTWAVE TROUGH
PASSAGE SHOULD ALLOW MEAN LOW-LEVEL FLOW TO VEER TO W'ERLY FOR A
TIME AND ALLOW LES TO IMPACT FAR-NE OH AND NW PA FOR AT LEAST
SEVERAL HOURS. AS A RESULT, OUR LATEST OFFICIAL SNOWFALL
FORECAST CALLS FOR 1-5" OF FRESH LES ACCUMULATION ALONG/NEAR THE
LAKESHORE FROM LAKE COUNTY, OH THROUGH ERIE COUNTY, PA BETWEEN
7 AM SUNDAY AND 7 PM TUESDAY. WE WILL CONTINUE TO MONITOR TRENDS
IN NWP MODEL GUIDANCE CLOSELY.
THE THERMODYNAMIC ENVIRONMENT SHOULD REMAIN FAVORABLE, OVERALL,
FOR ADDITIONAL LAKE ERIE LES TUESDAY NIGHT THROUGH THIS
SATURDAY. HOWEVER, AS THE WARM SECTOR BRIEFLY OVERSPREADS THE
LAKE ERIE REGION OVERNIGHT TUESDAY NIGHT INTO WEDNESDAY, THERE
SHOULD BE A BRIEF HIATUS FROM THE LES AS ICE-FREE LAKE SURFACE
TO 850 MB TEMPERATURE DIFFERENCES SHRINK TO LESS THAN 13C FOR A
TIME. EXACT MEAN LOW-LEVEL FLOW DIRECTION AND LES PLACEMENT,
INTENSITY, AND AMOUNTS ARE LESS CERTAIN TUESDAY NIGHT THROUGH
THIS SATURDAY, BUT THE MORE-RELIABLE GEM AND ECMWF MODELS
SUGGEST SHORTWAVE TROUGH PASSAGES WILL BE ACCOMPANIED BY MEAN
LOW-LEVEL FLOW VARYING BETWEEN MAINLY SW'ERLY AND W'ERLY. THUS,
LES MAY IMPACT OUR PRIMARY SNOWBELT COUNTIES AND VICINITY AT
TIMES. NOTE: SURFACE WINDS OVER LAKE ERIE SHOULD REMAIN STRONG
ENOUGH THROUGH THE UPCOMING WEEK TO PREVENT THE LAKE FROM
FREEZING-OVER COMPLETELY.
KEY MESSAGE 4...
OUTSIDE OF THE LES, PERIODS OF WIDESPREAD SNOW SHOULD IMPACT OUR
REGION SUNDAY NIGHT INTO MONDAY DUE TO LOW-LEVEL CONVERGENCE
AND MOIST ASCENT ALONG THE ARCTIC FRONT AND MOIST ISENTROPIC
ASCENT ALOFT, AHEAD OF THE ACCOMPANYING SHORTWAVE TROUGH AXIS.
THIS WIDESPREAD SNOW SHOULD TOTAL 2" OR LESS. ADDITIONAL PERIODS
OF WIDESPREAD SNOW, OUTSIDE THE AFOREMENTIONED LES, SHOULD
IMPACT NORTHERN OH AND NW PA TUESDAY NIGHT THROUGH SATURDAY DUE
TO MOIST ISENTROPIC ASCENT AHEAD OF SHORTWAVE TROUGH AXES, MOIST
ISENTROPIC ASCENT ALONG THE UPPER-REACHES OF THE WARM FRONT
TUESDAY NIGHT, AND LOW-LEVEL CONVERGENCE/MOIST ASCENT ALONG
WEDNESDAY'S COLD FRONT. ADDITIONAL SNOW ACCUMULATIONS SHOULD
OCCUR, BUT EXACT AMOUNTS ARE UNCERTAIN AT THIS JUNCTURE.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
THE MAIN FOCUS THROUGH 20 OR 21Z WILL BE A BAND OF SNOW SHOWERS
AND SQUALLS ALONG A COLD FRONT, EXTENDING FROM NEAR HZY TO CAK
AND MOVING EAST AT ABOUT 30KT. BRIEF LIFR VSBY AND A QUICK
ACCUMULATION OF SNOW IS ACCOMPANYING THESE SNOW SHOWERS AND
SQUALLS, ALONG WITH WIND GUSTS UP TO 35KT. MVFR CEILINGS LINGER
FOR A FEW HOURS BEHIND THE FRONT, BEFORE EITHER SCATTERING OUT
OR RISING TO VFR INTO THIS EVENING. MVFR CEILINGS MAY RETURN
SUNDAY MORNING. SOUTH-SOUTHWEST WINDS AHEAD OF THE FRONT ARE
TURNING MORE WEST-SOUTHWEST AND 10-15KT WITH GUSTS 20-25KT
BEHIND THE FRONT. WINDS WILL LOSE THEIR GUSTINESS THIS EVENING,
OUTSIDE OF ERI WHERE GUSTS WILL CONTINUE LONGER INTO THE NIGHT.
OUTLOOK...NON-VFR POSSIBLE IN SNOW SHOWERS SUNDAY NIGHT INTO MONDAY.
NON-VFR MAY LINGER IN LAKE EFFECT SNOW ACROSS NORTHEAST OHIO
AND NORTHWEST PENNSYLVANIA TUESDAY THROUGH WEDNESDAY.
MARINE
ICE COVERAGE CONTINUES TO EXPAND ACROSS THE WESTERN BASIN OF
LAKE ERIE. HAZARDOUS MARINE CONDITIONS ACROSS THE CENTRAL AND
EASTERN BASINS WILL PERSIST INTO NEXT WEEK AS MULTIPLE SYSTEMS
MOVE ACROSS THE GREAT LAKES.
CONFIDENCE IS INCREASING FOR A COMBINATION OF GALES AND FREEZING
SPRAY MONDAY INTO TUESDAY ACROSS THE CENTRAL AND EASTERN BASIN
OF LAKE ERIE AS A CLIPPER SLIDES EAST THROUGH THE GREAT LAKES,
USHERING IN WEST TO SOUTHWEST WINDS OF 30 TO 35 KNOTS. IN
ADDITION, THIS SYSTEM WILL EXTEND AN ARCTIC FRONT ACROSS THE
REGION, WITH LAKE AIR TEMPERATURES OVER ICE- FREE AREAS EXPECTED
TO DROP INTO THE LOW TEENS. IF TRENDS CONTINUE, A GALE WATCH
APPEARS LIKELY IN THE NEXT FORECAST CYCLE.
FOLLOWING THIS SYSTEM, SOUTHWEST WINDS WILL REMAIN ELEVATED,
AROUND 25 KNOTS, INTO WEDNESDAY. WINDS SHOULD GRADUALLY SUBSIDE
TO 20 KNOTS OR LESS AND BEGIN TO FAVOR A WEST DIRECTION BY
THURSDAY.
CLE WATCHES/WARNINGS/ADVISORIES
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LEZ146>149.
DISCUSSION...JASZKA
AVIATION...SULLIVAN
MARINE...KAHN
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