FXUS61 KCLE 250839
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
339 AM EST FRI DEC 25 2009
.SYNOPSIS...
A STRONG LOW PRESSURE ACROSS THE MIDDLE MISSISSIPPI VALLEY WILL LIFT
A WARM FRONT ACROSS THE AREA TODAY. THE LOW WILL DRAG A COLD FRONT
ACROSS THE AREA TONIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST QUESTION OF THE DAY IS WILL THE SURGE OF WARM AIR BEAT THE
APPROACHING RAIN? RAIN HAS ALREADY PUSHED NORTHEAST OF DAYTON WITH
MANSFIELD ALREADY WARMING TO 38 DEGREES. EXPECT ALL THE
PRECIPITATION ACROSS THE WESTERN PORTION OF THE FORECAST AREA TO
FALL AS RAIN AS DEW POINTS ARE ALREADY IN THE MID TO UPPER 20S AND
DO NOT THINK EVAPORATIONAL COOLING WILL OVERCOME THE WARM SURGE.
KEPT FREEZING RAIN ADVISORY FOR THE INLAND SNOWBELT EAST OF
CLEVELAND AND THE MAHONING VALLEY. THINK IT MAY TAKE A BIT LONGER
TO SCOUR OUT THE VALLEYS...PLUS EVAPORATIONAL COOLING SHOULD BE A
BIGGER FACTOR AS DEW POINTS CURRENTLY HOVERING AROUND 20. EXPECT
THIS TO BE A VERY SHORT LIVED EVENT.
WITH SOUTHEAST DOWN SLOPPING FLOW DO NOT EXPECT ANY FREEZING PRECIP
ALONG THE LAKE SHORE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
GOOD LOW LEVEL JET DEVELOPS THIS AFTERNOON. THE 925MB WINDS
INCREASE TO 50 KNOTS AND THE 850MB WINDS TO 75 KNOTS BY 21Z.
BUFKIT MOMENTUM TRANSFER INDICATES A STABLE CONDITION WITH A PEAK
GUST WITH 25 TO 30 KNOTS. INVERSION QUIT STRONG BUT THERE COULD BE A
FEW HOURS OF GUSTS BETWEEN 40 AND 45 KNOTS LATE THIS AFTERNOON. WILL
NOT GO WITH AN ADVISORY ATTM.
THE COLD AIR SWEEPS ACROSS THE AREA TONIGHT. BUT WITH 850MB TEMPS
ONLY BETWEEN MINUS 10C TO MINUS 12C AND WITH A SOUTHWEST FLOW OVER
THE LAKE DO NOT EXPECT ANY SIGNIFICANT LAKE EFFECT SNOW THIS
WEEKEND. DO GET A SECONDARY SHOT OF COLD AIR SUNDAY AS NEXT FRONT
MOVES THROUGH. THIS WILL PRODUCE MORE WIDESPREAD SNOW. SECONDARY
TROUGH MOVES ACROSS THE LAKE MONDAY SETTING UP THE POTENTIAL FOR
LAKE EFFECT SNOWS AS WINDS BECOME WESTERLY OVER THE LAKE.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
00Z OPERATIONAL RUNS OF THE GFS AND ECMWF ARE IN FAIRLY GOOD
AGREEMENT AND FAIRLY CONSISTENT WITH THE PREVIOUS LONG TERM FORECAST
AT LEAST INTO WEDNESDAY. A COLD FRONT DROPS SOUTH ACROSS THE AREA
LATE MONDAY...LEAVING A TROUGH BACK ACROSS THE LOWER LAKES MONDAY
NIGHT WITH A COLD NWLY FLOW ACROSS LAKE ERIE. HIGH PRESSURE
BEGINS TO BUILD INTO THE REGION TUESDAY. LAKE EFFECT SNOW SHOWERS
MONDAY NIGHT INTO TUESDAY THOUGH DIMINISHING IN THE WEST BY TUESDAY
MORNING. CONTINUED WITH THE LIKELY POPS FOR NE OHIO AND NW
PENNSYLVANIA MONDAY NIGHT AND EARLY TUESDAY...TAPERING TO CHANCE
POPS IN THE AFTERNOON. FAIRLY COLD 8H TEMPERATURES IN THE -14C TO
-18C RANGE HAS THE POTENTIAL FOR A SIGNIFICANT LAKE EFFECT EVENT.
THEN HIGH PRESSURE SLIDES ACROSS THE AREA TUESDAY NIGHT MOVING EAST
OF THE AREA ON WEDNESDAY. CONTINUED WITH A DRY FORECAST TUESDAY
NIGHT INTO WEDNESDAY. ECMWF MOVES THE HIGH OFF TO THE EAST A LITTLE
FASTER ON WEDNESDAY AND STARTS TO BRING PRECIP BACK INTO THE AREA
LATE IN THE DAY. FOR NOW FOLLOWED PREVIOUS FORECAST AND GFS MODEL
KEEPING WEDNESDAY DRY. THEN MENTION A CHANCE OF SNOW SHOWERS MAINLY
IN THE WEST WEDNESDAY NIGHT WITH AN APPROACHING COLD FRONT AND
ACROSS THE AREA ON THURSDAY AS THE FRONT MOVES INTO THE AREA.
&&
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL BE COMING TO AN END BY DAYBREAK FRIDAY. WARM
ADVECTION INDUCED PRECIPITATION WILL BE SPREADING UP FROM THE
SOUTHWEST LATE TONIGHT AND FRIDAY MORNING. THE BIGGEST QUESTION IS
THE PRECIPITATION TYPE. DEW POINT ARE IN THE MID 20S AND THE
SOUTHEAST WINDS WILL BE ON THE INCREASE OVERNIGHT. THE RAIN SHOULD
START OUT LIGHT AND THAT WILL HELP THE DEW POINT TO INCREASE AND
NOT ALLOW FOR ALOT OF EVAPORATIVE COOLING BUT WE WILL HAVE SOME.
BASED ON LOOKING AT A LOT OF GUIDANCE AND EXPERIENCE THE BEST TAF
SITE FOR FREEZING RAIN IS YNG. CAK...MFD AND TOL MAY HAVE A BRIEF
PERIOD OF FREEZING RAIN. CONFIDENCE IS STILL HIGH FOR FDY AND ERI NOT
TO HAVE ANY FREEZING RAIN. CONFIDENCE IN NO FREEZING RAIN HAS
DROPPED A LITTLE AT CLE BUT AS THE SOUTHEAST WINDS INCREASE
OVERNIGHT THE DOWNSLOPE SHOULD HELP KEEP TEMPERATURES ABOVE
FREEZING AT CLE. THIS IS ASSUMING THAT THE RUNWAY TEMPERATURES
WILL STAY ABOVE FREEZING. OF COURSE ALL THIS IS BEING MONITORED.
ONCE THE RAIN STARTS MAINLY MVFR TO IFR CONDITIONS WITH
DEVELOP...MVFR FOR THE VISIBILITY WITH IFR MAINLY FOR THE CEILING.
THE OTHER OVERNIGHT CONCERN IS LOW LEVEL WIND SHEAR. AT THIS TIME
I FEEL THAT THE WINDS WILL START TO BECOME GUSTY ABOUT THE TIME
THE STRONGEST WINDS ALOFT OCCUR AND ANY LOW LEVEL WIND SHEAR WILL
BE BELOW CRITERIA.
AFTER THE OCCLUDED FRONT MOVES THROUGH FRIDAY NIGHT A DRY SLOT
WILL DEVELOP AND HIGH END MVFR CONDITIONS WILL DEVELOP.
.OUTLOOK...NON-VFR CONDITIONS...MAINLY MVFR WILL OCCUR THROUGH
MONDAY. GUSTY WINDS WILL ALSO CONTINUE EARLY FRIDAY NIGHT.
&&
.MARINE...
EAST WINDS GENERALLY IN THE 15 TO 20 KNOT RANGE EARLY THIS MORNING
WILL BEGIN TO PICKUP TO 15 TO 25 KNOTS AND BECOME SOUTHEAST THIS
MORNING. A SCA WILL CONTINUE INTO TONIGHT. WINDS WILL BECOME MORE
SOUTHERLY OR SOUTHWESTERLY LATE TONIGHT AND SATURDAY WITH WINDS AND
WAVES DECREASING. A COLD FRONT DROPPING SOUTH ACROSS THE LAKE LATE
MONDAY WILL CAUSE WINDS TO INCREASE AGAIN MONDAY AND MONDAY NIGHT
BEFORE DIMINISHING AGAIN TUESDAY. WINDS WILL BE CLOSE TO OR POSSIBLY
REACH GALE FORCE LATE MONDAY AND MONDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR OHZ013-014-023-
033.
PA...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...DJB
NEAR TERM...DJB
SHORT TERM...DJB
LONG TERM...RANDEL
AVIATION...KIELTYKA
MARINE...RANDEL
