FXUS61 KCLE 150903
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
403 AM EST TUE DEC 15 2009
.SYNOPSIS...
A COLD FRONT OVER THE APPALACHIANS WILL MOVE OFF THE EAST COAST
TODAY. HIGH PRESSURE OVER THE PLAINS STATES WILL MOVE TO THE OHIO
VALLEY BY WEDNESDAY. A TROUGH OF LOW PRESSURE WILL LINGER OVER THE
EASTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT IS EAST OF THE AREA. DECENT COLD ADVECTION TO OCCUR
TODAY. BOUNDARY LAYER TEMPERATURES SHOULD BE COLD ENOUGH TO SUPPORT
SNOW BY DAYBREAK WEST OF THE I-71 CORRIDOR. THERE WILL LIKELY BE
LITTLE UPWARD MOTION BY THAT TIME EXCEPT OVER EXTREME NE OH/NW PA
WHERE SOME LAKE ENHANCEMENT AND OROGRAPHIC LIFT MAY LINGER. WILL
MENTION FLURRIES NW OHIO AND A MIX OF LIGHT RAIN/DRIZZLE/SNOW
BECOMING SNOW SHOWERS/FLURRIES NE OH/NW PA. WILL LIKELY NOT GET COLD
ENOUGH FAST ENOUGH FOR ANY FREEZING DRIZZLE. TEMPS SHOULD BE STEADY
OR FALLING ALL DAY.
TRAILING SHORT WAVE NEAR LAKE SUPERIOR SHOULD CATCH THE EASTERN
GREAT LAKES LATE TODAY AND THE FIRST HALF OF TONIGHT. THE
INGREDIENTS FOR OPTIMUM LAKE EFFECT SNOW SEEMINGLY DO NOT COME
TOGETHER. THE INVERSION DROPS QUICKLY TONIGHT AND TEMPERATURES ALOFT
DO NOT GET COLD ENOUGH QUICKLY ENOUGH FOR MAXIMUM SNOW GROWTH. WEST
TO NORTHWEST FLOW WOULD SEND WHAT SNOW THAT DOES DEVELOP INLAND IN
MULTIPLE BANDS. THE BEST CHANCE FOR A FEW INCHES OF SNOW WOULD BE
ACROSS INLAND ERIE COUNTY PA AND PERHAPS NORTHERN CRAWFORD COUNTY
PA. AT THIS POINT THERE WOULD NOT SEEM TO BE ENOUGH SNOW TO WARRANT
A SNOW ADVISORY ALTHOUGH THE SNOW THAT DOES FALL MAY COME WITHIN A
FEW HOURS THIS EVENING/EARLY TONIGHT SO SOME SLIPPERY CONDITIONS MAY
DEVELOP SOUTH OF I-90 ACROSS NW PA WITH LESSER AMOUNTS IN GEAUGA AND
ASHTABULA COUNTIES.
SKIES SHOULD ESSENTIALLY CLEAR ACROSS NW OHIO THIS EVENING EXCEPT
FOR A FEW PATCHES OF LAKE MICHIGAN CLOUDS.
AIRMASS UPSTREAM LOOKS PRETTY COLD. GRANTED...THE COLD IS BEING
ENHANCED BY THE SNOW COVER OVER THE UPPER MIDWEST BUT DEWPOINTS WILL
PLUNGE BY LATE TODAY. MIN TEMP FORECAST FOR TONIGHT WILL BE CLOSER
TO THE NAM/MET MOS GUIDANCE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MODELS HINT AT ANOTHER SHORT WAVE LATER WEDNESDAY. SHORT WAVE
COMBINED WITH THE ONSET OF WARM ADVECTION COULD TRIGGER ANOTHER
ROUND OF LAKE EFFECT/LAKE ENHANCED SNOW SHOWERS EXTREME NE OH/NW PA
ALTHOUGH IT DOES NOT LOOK IMPRESSIVE AT THIS TIME. CANNOT RULE OUT A
LOCAL INCH OR TWO OF ADDITIONAL SNOW MAINLY ACROSS INLAND NW PA
LATER WEDNESDAY AND WEDNESDAY NIGHT. SOME FLURRIES MAY DEVELOP
ELSEWHERE ACROSS NE OH/NW PA WITH SOME CLOUDS ACROSS NW OHIO. TEMPS
WILL FALL OFF IN AREAS WHERE THE WIND DROPS OFF. ELSEWHERE
TEMPERATURES MAY NOT DROP A LOT WEDNESDAY NIGHT. SURFACE HIGH BUILDS
IN ON THURSDAY BUT DIFFERENTIAL ADVECTION PROGGED TO CONTINUE ALOFT
SO THERE WILL LIKELY BE SOME ALTOCUMULUS AND PERHAPS SOME LINGERING
STRATOCUMULUS ESPECIALLY OVER THE SNOWBELT.
ALL MODELS DEVELOP AN INVERTED TROUGH BY THE END OF THE WEEK IN
RESPONSE TO A DEEPENING TROUGH ALOFT. NAM/WRF DEVELOPS A MORE WELL
DEFINED SURFACE LOW WHICH SEEMS OVERDONE. WITH THE TROUGH INITIALLY
DEEPENING WELL TO THE WEST...DO NOT WANT TO HURRY THE PRECIPITATION
AS THERE WILL LIKELY REMAIN SOME LOW DEWPOINT AIR TO OVERCOME AND A
DRY EAST-NORTHEAST FLOW. WILL MENTION A CHANCE OF LIGHT SNOW BY
FRIDAY NIGHT/SATURDAY. WITH THE FLOW FROM THE EAST... TEMPERATURES
WILL NOT HAVE A CHANCE TO WARM UP MUCH. GUIDANCE LOOKS PRETTY GOD
WITH MAX TEMPS IN THE UPPER 20S AND LOWER 30S.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A TROUGH AXIS WILL EXTEND NORTHWEST ACROSS THE AREA ON SATURDAY WITH
SOME LIMITED ASSOCIATED MOISTURE. COLD AIR ADVECTION WILL ALSO TAKE
PLACE AS HIGH PRESSURE NUDGES SOUTH INTO THE REGION DURING THE DAY.
CURRENT FORECAST SUGGESTS A CHANCE OF SNOW FOR SATURDAY ALTHOUGH
GUIDANCE ONLY SHOWS A SLIGHT CHANCE. WILL CONTINUE WITH SLIGHT
CHANCE IN THE WEST HALF AND CHANCE IN THE EAST HALF.
SATURDAY NIGHT LOW PRESSURE SYSTEM MOVES UP THE ATLANTIC COAST AND
FEEDS MOISTURE BACK TO THE NORTHWEST INTO THE AREA. THIS MOISTURE
WILL CAUSE A THREAT FOR LIGHT SNOW SATURDAY NIGHT CONTINUING INTO
SUNDAY. COLD AIR ADVECTION AND NORTHWEST FLOW WILL CAUSE LAKE EFFECT
SNOW SHOWERS TO DEVELOP ACROSS THE REGION SUNDAY NIGHT AND CONTINUE
MONDAY AND TUESDAY.
TEMPERATURES DURING THE EXTENDED PERIODS WILL BE IN THE 20S TO LOWER
30S FOR HIGHS AND LOWS WILL BE IN THE TEENS.
EUROPEAN AND GFS MODELS HAVE SOME MAJOR DIFFERENCES TO OVERCOME TO
DETERMINE WHETHER CHRISTMAS WILL BE A WHITE ONE. EUROPEAN IS
POINTING TOWARD A COLD SNOWY CHRISTMAS WITH LAKE EFFECT WHILE GFS
SUGGESTS A WARM UP AND RAIN ON CHRISTMAS EVE WITH A STRONG COLD
FRONT MOVING THROUGH AREA DEVELOPING SNOW BY EVENING ON CHRISTMAS
EVE. IT IS A LONG WAYS OFF SO WE WILL KEEP AN EYE ON IT OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
COLD FRONT WILL BE JUST ABOUT THROUGH THE AREA BY 06Z. PATCHY IFR
CIGS CONTINUE ACROSS THE AREA. THESE SHOULD LIFT TO MVFR BY
DAYBREAK AS GOOD MIXING OCCURS. THERE WILL BE A PRETTY GOOD
INTRUSION OF COLD AIR INTO THE AREA TONIGHT. HAVE ADDED SOME SHSN
TO PREFERRED AREAS. KERI WILL LIKELY SEE SOME IFR SNOW LATER
TUESDAY. IN THE WEST CIGS WILL BECOME VFR NO LATER THAN MIDDAY WITH
CLEARING EXPECTED DURING THE EVENING. IN THE EAST...CIGS SHOULD
STAY MVFR THROUGH THE END OF THE TAF PERIOD. W TO NW FLOW WILL
BECOME GUSTY AFTER DAYBREAK.
.OUTLOOK...NON VFR WEATHER TUESDAY EVENING THROUGH THURSDAY
MAINLY EASTERN PORTION AND EVERYWHERE IN THE FORECAST AREA FRIDAY
AND SATURDAY.
&&
.MARINE...
WILL KEEP SMALL CRAFT ADVISORIES FLYING AS WESTERLY FLOW CONTINUES
OVER THE LAKE AT ABOUT 15 TO 25 KNOTS. IT APPEARS THIS TREND WILL
LAST FOR SOME TIME UNTIL ABOUT WEDNESDAY NIGHT WHEN WINDS FINALLY
START TO DIMINISH. GENERALLY LIGHT AND VARIABLE FLOW SETS UP FOR
THURSDAY CONTINUING INTO FRIDAY. THEN...NORTHWEST FLOW DEVELOPS BY
FRIDAY NIGHT AT 10 TO 15 KNOTS. THIS SHOULD REMAIN BELOW SMALL
CRAFT CRITERIA INTO SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...KOSARIK
LONG TERM...LOMBARDY
AVIATION...KUBINA
MARINE...LOMBARDY
