FXUS61 KCLE 030502
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
1202 AM EST THU DEC 3 2009
.SYNOPSIS...
LOW PRESSURE IN KENTUCKY WILL MOVE NORTHEAST ACROSS EASTERN OHIO
TONIGHT AND THE SAINT LAWRENCE VALLEY ON THURSDAY. COLDER AND
DRIER AIR WILL SPREAD IN BEHIND THE LOW AND PERSIST INTO THE
WEEKEND. SOME LIGHT LAKE EFFECT SNOW AND/OR FLURRIES ARE POSSIBLE BY
THURSDAY NIGHT INTO THE WEEKEND BUT A SIGNIFICANT LAKE EFFECT
EVENT IS NOT EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RAIN HAS SPREAD OVER MOST OF THE FORECAST AREA. DOWNSLOPE FLOW WILL
PERSIST EARLY TONIGHT AND WILL TRIM QPF AMOUNTS A BIT ACROSS EASTERN
OHIO. RAINFALL AMOUNTS SHOULD VARY FROM ABOUT 1/3 OF AN INCH TO 3/4
OF AN INCH BY LATE TONIGHT. TEMPS WILL DROP EARLY TONIGHT AS AIR
BECOMES RAIN COOLED...THEN COULD RISE A COUPLE OF DEGREES ACROSS NE
OH/NW PA AS THE SURFACE LOW TRACKS ACROSS THE AREA...THEN DROP AGAIN
TOWARD MORNING AS THE COLDER AIR BEGINS TO WRAP IN BEHIND THE
SYSTEM. WILL NOT TRY TO EXPLAIN THIS IN THE TEXT BUT SOME OF THIS
TREND WILL BE VISIBLE ON THE HOURLY/3 HOURLY TEMP FORECAST. BOUNDARY
LAYER DOES NOT SEEM TO COOL DOWN FAST ENOUGH TO SUPPORT SNOW LATER
AND DRIER AIR WILL FILTER IN AS FAST AS THE COOLER AIR. ALSO VERY
LITTLE THREAT OF ANYONE GETTING TO THE FREEZING MARK BY DAYBREAK AS
MIN TEMPS SHOULD ONLY REACH THE MID 30S ACROSS NW OH BY DAYBREAK.
WITH THE GROUND WARM SHOULD NOT HAVE ANY THREAT OF ICY SPOTS OR WET
SNOW OR ANY OF THAT MESSY STUFF.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
DRIER AIR SWEEPS IN QUICKLY LATE TONIGHT AND THURSDAY MORNING. SOME
LAKE ENHANCED SHOWERS ARE POSSIBLE EARLY ACROSS EXTREME NE OH/NW PA
BUT RAIN SHOWERS SHOULD TAPER OFF BEFORE IT GET COLD ENOUGH FOR A
CHANGE OVER TO SNOW.
FLOW BACKING FROM WEST-NORTHWEST TO WEST SOUTHWEST. COLDER AIR SEEMS
AS IF IT WILL FILTER IN RATHER SLOWLY. IT IS COLD ENOUGH FOR TRUE
LAKE EFFECT BY LATE AFTERNOON AND THERE IS A SHORT WINDOW OF
OPPORTUNITY FOR SOME SNOW BANDS BEFORE THE FLOW BACKS TO SOUTHWEST
AND THE SNOWBANDS HEAD TOWARD WESTERN NEW YORK BEFORE DAYBREAK ON
FRIDAY. THIS WOULD SEEM TO PUT FRIDAY IN A LULL AS ANY ACTION
OUTSIDE OF SOME FLURRIES WOULD BE GOING INTO WESTERN NEW YORK.
ALWAYS A LITTLE NERVOUS ABOUT ERIE COUNTY PA AS THE SOUTHWEST FLOW
CAN CLIP ERIE COUNTY ESPECIALLY AROUND NORTHEAST PA.
A LOT OF RIDGING ALOFT AND AT THE SURFACE PROGGED FOR THE WEEKEND.
FLOW PROGGED TO VEER MORE TOWARD THE WEST AND NORTHWEST ON SATURDAY
AS ALL MODELS DEVELOP A SURFACE LOW OFF THE SOUTHEAST COAST. WITH
THE TROUGH ALOFT MOVING IN THERE MAY BE A FAIR AMOUNT OF CLOUDS MOST
ANYWHERE AND PERHAPS A FEW SNOW SHOWERS/SNOW FLURRIES. THE POSITION
OF THE SURFACE HIGH TO OUR SOUTHWEST DOES LEAVE THE DOOR OPEN FOR
ENOUGH FLOW OFF THE LAKE FOR SOME SNOW BANDS. INVERSION IS PROGGED
TO BE SOMEWHAT SHALLOW. IT CERTAINLY DOES NOT LOOK LIKE A CLASSIC
SET UP BUT WOULD ANTICIPATE THAT A FEW MINOR SNOW BANDS WILL DEVELOP
WITH PERHAPS A SMALL LOCAL ACCUMULATION FROM LAKE AND NORTHERN
GEAUGA ACROSS NORTHWEST PA. ANY SNOW BANDS THAT GET GOING WILL LAST
INTO SUNDAY AS THE SURFACE HIGH SLOWLY SLIDES BY TO THE SOUTH AND
THE FLOW REMAINS NORTHWEST. AGAIN... ANY AMOUNTS WOULD LIKELY BE
LIGHT AND LOCALIZED AS THE SHEAR INCREASES AND WARM ADVECTION
DEVELOPS. FINGERS CROSSED. THE HIGH SHOULD BE EAST OF THE AREA BY
SUNDAY EVENING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GFS AND EUROPEAN MODELS BOTH IN FAIRLY GOOD AGREEMENT IN THE TRACK
OF THE STORM SYSTEM EXPECTED EARLY TO MID NEXT WEEK. IT IS STARTING
TO FEEL MORE LIKE EARLY DECEMBER COMPARED TO PREVIOUS DAYS AND THE
MODELS SHOW IT.
LOW PRESSURE IS PROGGED TO MOVE NORTHEAST ACROSS THE SOUTHERN GREAT
LAKES REGION MONDAY AND TUESDAY. COLD AIR MASS WILL ALREADY BE IN
PLACE AND AT THIS TIME...IT APPEARS THAT ALL OF THE PRECIPITATION
WILL BE IN THE FORM OF SNOW ACROSS THE FORECAST AREA THROUGH THE
DURATION OF THE EXTENDED PERIODS.
DUE TO THE POTENTIAL FOR AN EARLIER ARRIVAL OF SNOW SUNDAY NIGHT...I
DECIDED TO ADD MENTION OF A SLIGHT CHANCE OF SNOW SHOWERS. MODELS
SUGGEST A CLOSE PROXIMITY STATIONARY FRONT EITHER OVER OR NEAR THE
FORECAST AREA ALONG WITH ASSOCIATED MOISTURE. MOISTURE APPEARS TO
BE WEAK ALONG THE BOUNDARY AND WE MAY ONLY WIND UP WITH SOME
SCATTERED FLURRIES.
DEEPER MOISTURE SPREADS EAST TOWARD THE REGION DURING THE DAY MONDAY
AND 850 MB TEMPERATURES PROGGED TO BE BETWEEN -4C TO -8C ACROSS THE
FORECAST AREA. THIS SHOULD BE COLD ENOUGH TO SUPPORT SNOW MONDAY
DURING THE DAY.
EVEN COLDER AIR DOWN TO -12C AT 850 MB EXPECTED TO MOVE EAST INTO
THE REGION TUESDAY.
LOW PRESSURE WILL PUSH OFF TO THE EAST AND WEAK HIGH PRESSURE WILL
BUILD OVER THE FORECAST AREA SETTING UP A POSSIBLE LAKE EFFECT
SCENARIO WITH CYCLONIC INFLUENCE FOR TUESDAY NIGHT INTO WEDNESDAY.
GFS TRIES TO TRACK ANOTHER LOW INTO THE AREA BY WEDNESDAY. EUROPEAN
KEEPS LOW A BIT FURTHER SOUTH THAN THE GFS. STORM SYSTEM WILL KEEP A
CHANCE OF SNOW SHOWERS ACROSS THE AREA WEDNESDAY.
TEMPERATURES EXPECTED TO RUN IN THE MIDDLE TO UPPER 30S THROUGH THE
PERIOD FOR HIGHS AND LOWS IN THE 20S TO LOWER 30S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
DRY SLOT HAS MANAGED TO ERODE THE LOW DECK ACROSS THE EASTERN HALF
OF THE AREA HOWEVER WESTERN TERMINALS REMAIN IFR/LIFR. BASICALLY
AS THE LOW MOVES NORTHEAST OF THE AREA OVERNIGHT THE IFR/LIFR WILL
SWEEP EAST ACROSS THE AREA. WILL ATTEMPT TO TIME THIS AS IT MOVES
EAST ACROSS THE AREA. IN THE WEST EXPECT CONDITIONS WILL BEGIN TO
IMPROVE TO MVFR AROUND 12Z AND THEN TO VFR BY 18Z. FURTHER EAST
EXPECT THE LOWEST CONDITIONS TO BEGIN BETWEEN 8 AND 10Z LASTING
THROUGH 12 TO 14Z OR SO BEFORE IMPROVING TO MVFR. WINDS NOT TOO
GUST JUST YET EXCEPT FOR FAR NERN OHIO AND NWRN PA WHERE DOWNSLOPE
WINDS ARE GUSTING TO NEAR 30 KNOTS. EXPECT THIS WILL DIMINISH
9-10Z AS THE LOW NEARS HOWEVER IN GENERAL...EXPECT WEST/NW WINDS
WILL INCREASE LATE TONIGHT AND THROUGH THE MORNING HOURS THURSDAY.
.OUTLOOK...
PERIODS OF IFR AND MVFR CONDITIONS AT KERI THURSDAY THROUGH SUNDAY
IN LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
UPDATED...HAVE UPDATED TO ADD A SMALL CRAFT ADVISORY. ISSUED FIRST
FOR THE EAST HALF AND THEN JUST ADDED THE WESTERN BASIN AT 3 AM
FOR THE 'TOMORROW' FORECAST. SOUTHEAST WINDS GUSTING TO 30 KNOTS
IN NWRN PA AND FAR NERN OHIO LIKELY CAUSING SMALL CRAFT CONDITIONS
CURRENTLY. THE WESTERN SECTIONS WILL DEVELOP SMALL CRAFT
CONDITIONS ON THURSDAY WITH WNW FLOW BEHIND THE LOW SO WILL JUST
ISSUE THE WEST END AS WELL.
PREVIOUS...WINDS HAVE BEGUN TO SWITCH TO THE SOUTHEAST. EXPECT
THE WINDS TO CONTINUE TO CHANGE OVERNIGHT AS STRONG LOW PRESSURE
MOVES ACROSS THE REGION. HAVE USED A BLEND OF MODELS TODAY WHICH
TAKES THE LOW JUST EAST OF LAKE ERIE BY DAYBREAK THURSDAY. WINDS
WILL BECOME N TO NE THIS EVENING AS THE LOW APPROACHES. BY
MORNING...THE WESTERN HALF OF THE LAKE WILL BE NW WITH SW TO W
FLOW FURTHER EAST. AT THE SAME TIME WINDS WILL PICK UP AND EXPECT
WINDS TO GET CLOSE TO 30 KNOTS. LATER SHIFTS WILL NEED TO ISSUE A
SMALL CRAFT AS WE ARE STILL OUTSIDE OF THE 12 HOUR WINDOW NEEDED.
THE FLOW WILL BECOME WEST TO SOUTHWEST THURSDAY AFTERNOON AND THEN
CHANGE LITTLE THROUGH THE WEEKEND. SPEEDS WILL BEGIN TO DIMINISH
LATE THURSDAY AND THURSDAY NIGHT. FROM FRIDAY EVENING THROUGH
SUNDAY SPEEDS WILL GENERALLY BE UNDER 15 KNOTS. LIGHT SOUTHERLY
WINDS CAN BE EXPECTED FOR MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST FRIDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY FROM 3 AM THURSDAY TO 5 AM EST FRIDAY FOR
LEZ142>145.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...KOSARIK
LONG TERM...LOMBARDY
AVIATION...TK
MARINE...TK
