Lake-Effect Snow in Ohio, December 18 to 19, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
416 PM EST FRI DEC 18 2015

.SYNOPSIS...
A TROUGH WILL LINGER OVER THE EASTERN GREAT LAKES INTO SATURDAY THEN
HIGH PRESSURE WILL EXPAND NORTH UP THE OHIO VALLEY. THE HIGH WILL
SHIFT TO THE EAST COAST ON SUNDAY AS LOW PRESSURE MOVES INTO THE
UPPER MIDWEST. THE LOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON
MONDAY WITH THE TRAILING COLD FRONT STALLING ACROSS LAKE ERIE ON
TUESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
UPPER LEVEL TROUGH IS PIVOTING EASTWARD INTO THE CENTRAL GREAT LAKES
WHILE THE SURFACE COLD FRONT IS MAKING ITS WAY ACROSS NORTH CENTRAL
OHIO AS OF 3 PM. SCATTERED FLURRIES WITH A FEW LIGHT SNOW SHOWERS
ARE ACCOMPANYING THE FRONT WHILE THE LAKE EFFECT SNOW BANDS ARE
STILL DEVELOPING OUT OVER LAKE ERIE. THESE BANDS SHOULD INCREASE
CONSIDERABLY OVER THE NEXT SEVERAL HOURS WITH BOTH MOISTURE AND
INSTABILITY INCREASING AS A -38C COLD POOL ARRIVING AT 500MB. NO
CHANGES MADE TO THE HEADLINES ALTHOUGH MINOR ADJUSTMENTS WERE MADE
TO TRY TO REFINE ACCUMULATIONS. LEFT A MENTION OF POSSIBLE
THUNDERSTORMS IN FOR TONIGHT.

WITH THE PASSAGE OF THE COLD FRONT...THE SOUTHWEST FLOW WILL BECOME
SLIGHTLY MORE WESTERLY AND LAKE EFFECT SNOW BANDS WILL START TO
IMPACT THE NORTHEAST LAKESHORE AREAS. SEVERAL GOOD BURSTS OF SNOW
ARE EXPECTED THIS EVENING WITH THE FLOW GRADUALLY SHIFTING INLAND
SOME WITH THE PASSAGE OF THE LEADING SHORTWAVE ALOFT. WE LOSE SOME
OF THE MOISTURE BEHIND THE FIRST WAVE BEFORE A SECONDARY WAVE
WHICH CAN BE SEEN ON WATER VAPOR IMAGERY APPROACHING NORTHERN
ILLINOIS ARRIVES AFTER MIDNIGHT. ANOTHER SURFACE TROUGH IS NOTED
IN THE SURFACE PRESSURE FIELDS WHICH WILL ENHANCE LAKE EFFECT
SNOW LATER TONIGHT. WE WILL GET A BOOST OF MOISTURE OFF LAKE
MICHIGAN WHICH IS EXPECTED TO EVOLVE INTO A WEST TO EAST ORIENTED
BAND COMING OFF THE LAKE BY 3 OR 4 AM. PLACEMENT OF THIS BAND
REMAINS THE TOUGH PART OF THE FORECAST HEADING INTO SATURDAY. 1-2
INCH PER HOUR SNOWFALL RATES ARE POSSIBLE WHERE THE BAND SETS UP
AND COULD LEAD TO QUICK ACCUMULATION. TRIED TO ORIENT THIS BAND IN
ACROSS LAKE COUNTY TOWARDS ASHTABULA AND SOUTHERN ERIE/NORTHERN
CRAWFORD COUNTIES ALTHOUGH IT COULD RESIDE CLOSER TO THE
LAKESHORE. LOWERED ACCUMULATIONS A LITTLE TOWARDS THE CITY OF
ERIE CLOSER TO 5 INCHES BUT AS ALWAYS THIS DEPENDS ON PLACEMENT
AND DURATION OF HEAVIER SNOW BANDS. HIGHER ACCUMUS ARE EXPECTED
OVER THE HIGHER TERRAIN.

DESPITE THE COLD FRONT...NOT EXPECTING TEMPERATURES TO DROP OFF MUCH
WITH CLOUDY SKIES AND WESTERLY WINDS OF 10-25 MPH. HIGHS ON SATURDAY
WILL BE LIMITED TO THE LOW 30S.

SNOW WILL START TO DIMINISH BY SATURDAY AFTERNOON AS THE RIDGE
STARTS TO BUILD NORTH UP THE OHIO VALLEY AND WE REALLY DRY OUT FROM
THE WEST. CONSIDERED ENDING THE HEADLINES A LITTLE SOONER BUT
DECIDED TO LET THE EVENT GET STARTED FIRST AND WILL MAKE
ADJUSTMENTS ON FUTURE CYCLES.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
CLOUDS SHOULD CLEAR OUT FROM NEARLY ALL AREAS ON SATURDAY NIGHT WITH
LIGHT WINDS AS THE RIDGE BUILDS. IT SHOULD BE A CHILLY NIGHT WITH
MANY INLAND AREAS DIPPING INTO THE TEENS.

SOUTHERLY FLOW RETURNS ON SUNDAY AHEAD OF THE NEXT TROUGH LIFTING
OUT OF THE PLAINS. TEMPERATURES RECOVER TO NEAR 40 DEGREES ON SUNDAY
WITH SHOWERS APPROACHING FROM THE WEST LATE SUNDAY NIGHT.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY.  THE PERIOD LOOKS MILD WITH
ALL RAIN FOR THE PRECIP TYPE.  THE PERIOD WILL START OUT WET ON
MONDAY AS THE LATEST IN A SERIES OF STRONG LOWS MOVES ACROSS THE
CENTRAL LAKES.  THE LOCAL AREA WILL BE ON THE WARM SIDE OF THIS
SYSTEM ONCE AGAIN WITH 50S A GOOD BET FOR TEMPS.  WILL CONTINUE WITH
LIKELY POPS AS QPF AMOUNTS COULD APPROACH HALF AN INCH.  SHOWERS
WILL CONTINUE EAST OF I-71 THROUGH DAYBREAK TUESDAY.  HIGH PRESSURE
WILL BRIEFLY BUILD IN FOR LATE TUESDAY AND TUESDAY NIGHT.  WET
WEATHER WILL RETURN ON WEDNESDAY IN STRONG WARM ADVECTION AHEAD OF
YET ANOTHER PLAINS STORM SYSTEM.  THIS SYSTEM WILL BE EVEN WARMER
THAN THE EARLY WEEK STORM AS THE SURFACE WILL BE MUCH FURTHER NORTH.
WILL AGAIN NEED FAIRLY HIGH POPS THROUGH THURSDAY.  IT SHOULD DRY
OUT FROM WEST TO EAST ON FRIDAY BUT TEMPS WILL REMAIN MILD.  MODELS
IN FAIR AGREEMENT WITH THE BIG PICTURE.  HAVE USED A BLEND OF
GUIDANCE TEMPS.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT 1 PM THIS AFTERNOON SATELLITE IMAGERY SHOWED CLOUDS
OVER MUCH OF NORTHERN OHIO AND NW PA AHEAD OF A SURFACE TROUGH
MOVING THROUGH THE CENTRAL GREAT LAKES. A MIXED BAG OF VFR/MVFR
CEILINGS WAS FOUND THROUGH THE CLOUDS IN WESTERN OHIO AS CLOUDS HANG
AROUND THAT 3000 FOOT THRESHOLD. AN AREA OF CLEARING MOVING ACROSS
NORTH CENTRAL OHIO WILL POSSIBLY CLEAR THE CEILINGS FOR A SHORT
DURATION AT CLE AND ERI AND EVEN AS FAR SOUTH AS CAK AND YNG.

THE MAIN EVENT FOR THIS TAF PERIOD WILL BE THE LAKE EFFECT SNOW
THAT WILL DEVELOP OFF OF LAKE ERIE THIS EVENING. COLD AIR AND
WESTERLY WINDS OFF OF WARM AND MOIST LAKE ERIE WILL SET UP SOME
LAKE EFFECT SNOW OVER NW PA AND EXTREME NE OHIO. ERI WILL BE THE
MAIN TERMINAL IMPACTED AS IFR CONDITIONS WILL DEVELOP AFTER DARK
AND CONTINUE THROUGH THE OVERNIGHT. SOME SNOW AND MVFR CONDITIONS
ARE POSSIBLE AT CLE AND YNG AS WELL. CEILINGS IN GENERAL ACROSS
THE AREA WILL DECREASE TO MVFR BY 09Z AND REMAIN THERE FOR A
COUPLE HOURS UNTIL DAY BREAK ON SATURDAY MORNING. SOME SNOW WILL
REMAIN AT ERI THROUGH THE DAY ON SATURDAY.

OUTLOOK...NON VFR EXTREME NE OHIO AND NW WEST PA SAT INTO SAT NIGHT
IN LAKE EFFECT SNOW SHOWERS. NON VFR POSSIBLE ON MONDAY.

&&

.MARINE...
SOUTH BASS IS SHOWING 22 KNOTS THIS AFTERNOON SO THE SMALL CRAFT
IS GOOD TO GO. EXPECT WINDS TO GRADUALLY DIMINISH ON SATURDAY AS
RIDGING OCCURS FROM THE SOUTH. THIS WILL CAUSE THE FLOW TO BECOME
SW DURING THE DAY. INCREASING S TO SW FLOW IS EXPECTED SUNDAY INTO
MONDAY AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE THROUGH LATE
MONDAY. WILL LIKELY NEED MORE SMALL CRAFT HEADLINES AT THAT TIME.
THE FLOW WILL BECOME NW BEHIND THE FRONT FOR A FEW HOURS BUT BY
MIDDAY TUESDAY THE FLOW WILL BE BACK TO THE SOUTH AHEAD OF YET
ANOTHER STORM SYSTEM. SOUTHERLY FLOW WILL THEN CONTINUE INTO
WEDNESDAY. THERE IS AN CHANCE FOR THUNDER ON THE EASTERN END OF
THE LAKE TONIGHT AND EARLY SATURDAY WITH ANY OF THE STRONG LAKE
EFFECT BANDS.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST SATURDAY FOR OHZ012-
     014-089.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST SATURDAY FOR PAZ003.
     LAKE EFFECT SNOW WARNING UNTIL 10 PM EST SATURDAY FOR PAZ001-
     002.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ146>149.
     SMALL CRAFT ADVISORY UNTIL 9 PM EST SATURDAY FOR LEZ142>145.

&&

SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA/SEFCOVIC
MARINE...KUBINA