FXUS61 KCLE 080327
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
1027 PM EST MON DEC 7 2009
.SYNOPSIS...
A TROUGH OF LOW PRESSURE OVER THE EASTERN GREAT LAKES WILL MOVE
NORTHEAST OVERNIGHT. HIGH PRESSURE OVER WEST VIRGINIA WILL BRIEFLY
EXPAND ACROSS THE LOWER GREAT LAKES TUESDAY MORNING. A MAJOR LOW
PRESSURE SYSTEM FROM THE SOUTHWEST WILL QUICKLY TRACK NORTHEAST
TUESDAY AND WEDNESDAY AND PASS OVER THE CENTRAL GREAT LAKES ON
WEDNESDAY. THIS WILL BRING THE POTENTIAL FOR STRONG WINDS AND
EVENTUALLY SIGNIFICANTLY COLDER AIR AFTER THE STORMS PASSES BY ON
THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
TROUGH ALOFT SLIDING ACROSS THE AREA EARLY TONIGHT. SOME CLEARING
OF THE STRATOCUMULUS HAS WORKED INTO NW OHIO AND SHOULD CONTINUE
TO SPREAD EAST. OF COURSE THE HIGH CLOUDS FROM THE SOUTHWESTERN
STORM SYSTEM WILL OVERSPREAD THE AREA EVEN QUICKER. FLOW ALOFT HAS
BECOME WEST NORTHWEST WHILE THE SURFACE FLOW REMAINS SOUTHWEST...A
NICE SET-UP FOR LOW LEVEL CONVERGENCE AND LAKE ENHANCED SNOW BANDS
EAST OF CLEVELAND ESPECIALLY ACROSS ERIE COUNTY PA. NOT TERRIBLY
COLD ALOFT AND NOT PARTICULARLY MOIST BUT ENOUGH TO SQUEEZE OUT
AN INCH IN MANY AREAS WITH TWO OR THREE INCHES IN ERIE COUNTY PA FROM
AROUND I-90 EASTWARD ACROSS THE ROUTE 19 CORRIDOR NORTH OR
WATERFORD TOWARD NORTHEAST AND COLT STATION. THE SNOW WILL
GRADUALLY TAPER OFF WITH JUST A FEW FLURRIES LATER AS THE RIDGING
INCREASES AND THE LOW LEVEL SHEAR INCREASES. DESPITE THE INCREASING
HIGH CLOUDS TEMPS WILL STILL LIKELY SNEAK DOWN A FEW DEGREES AS
THE WIND BECOMES RATHER LIGHT AND WE LOSE MUCH OF THE LOWER
CLOUDS. WILL MAKE ONLY A FEW VERY MINOR CHANGES TO MIN TEMP
FORECAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE OFF TO THE SOUTHEAST WILL RIDGE INTO THE REGION
TOMORROW MORNING ALLOWING FOR A BRIEF PERIOD OF DRY WEATHER. WENT
CLOSER TO COOLER MET NUMBER THAN MAV GUIDANCE GIVEN CLOUDS AND LIGHT
MIXING. THINKING TEMPS WILL ONLY SLOWLY CLIMB THROUGH THE DAY TO
MAXES RANGING IN THE MID TO UPPER 30S. COOLEST ACROSS INTERIOR NW
PA. HAVE FORECAST DRY THROUGH THE MORNING HOURS...THEN INCREASE POPS
FROM THE SOUTHWEST THROUGH THE AFTERNOON. THROUGH 00Z WED MENTION
MAINLY CHC POPS ACROSS THE FORECAST AREA WITH LIKELY IN FAR SW
ZONES. PRECIP ADVANCING INTO THE AREA AROUND AND AFTER 00Z QUICKLY
SO DRAMATICALLY INCREASE POPS GOING INTO THE TUE NIGHT PERIOD.
THE CONCERN CONTINUES TO BE OPPORTUNITY FOR MIXED PRECIP ACROSS THE
AREA. TEMPS CONTINUING TO WARM ALOFT THROUGH TUE NIGHT. 1000-850
THICKNESS...H850 TEMPS AND EVEN SURFACE TEMPS RATHER CLOSE TO
THRESHOLDS DURING THE PERIOD. DO NOT THINK COLDER AIR AT SURFACE HAS
MUCH OPPORTUNITY TO HOLD ON ACROSS THE WESTERN HALF OF THE AREA SO
THINKING NOW THERE MAY BE A FEW HOUR PERIOD OF SNOW OR MIXED
PRECIP...THEN GOING TO RAIN. THE EASTERN HALF MAY BE A BIT TRICKIER
WITH MIXED PRECIP PROLONGED THERE A BIT LONGER BUT EXPECTING A
CHANGEOVER TO RAIN THERE ALSO. MOST SIGNIFICANT CONCERN IS ACROSS
INTERIOR PORTIONS OF NW PA WHERE COLDER AIR WILL BE MOST DIFFICULT
TO ERODE AWAY AT LOWER LEVELS. THERE MAY BE SOME AREAS THAT SEE SNOW
AND MIXED PRECIP THEN THE LARGEST POTENTIAL FOR FREEZING RAIN LATE
TUESDAY NIGHT. FOR MUCH OF THE AREA NOT CONFIDENT ON ANY WINTER
HEADLINES AS ANY WINTRY PRECIP WILL BE RATHER SHORT LIVED.
HOWEVER...WILL NEED TO MONITOR POTENTIAL ESPECIALLY FOR INTERIOR
SECTIONS OF FAR NE OH AND NW PA.
LOWS TUESDAY NIGHT WILL OCCUR EARLY IN THE PERIOD...THEN GRADUALLY
RISE THROUGH THE OVERNIGHT FOR MOST OF THE AREA. LOW PRESSURE TO
PASS TO THE WEST OF THE AREA FOR WED THEN COLD FRONTAL PASSAGE FROM
WED MORNING THROUGH EARLY AFTERNOON ACROSS EASTERN AREAS. MAXES WILL
ACTUALLY BE RATHER MILD FOR THE EASTERN 2/3 OF THE AREA WED
MORNING...BUT THEN TEMPS DROP OFF SIGNIFICANTLY WED NIGHT.
MODELS LOCKED IN PRETTY WELL WITH BOTH GFS AND ECMWF BRINGING 975MB
LOW OVER LAKE HURON BY WEDNESDAY EVENING. NAM SHOWING SIMILAR
INTENSITY BUT A BIT FURTHER TO THE WEST. AS FAR AS WINDS
GO...CONCERNED LATE TUESDAY NIGHT AND EARLY WEDNESDAY ACROSS
LAKESHORE AREAS OF NW PA WITH GOOD DOWNSLOPING SE WINDS. ALSO...ONCE
COLD FRONT PUSHES THROUGH THE AREA CONCERNED WITH WINDS INCREASED
FROM WEST TO EAST THROUGH THE AFTERNOON. NOT QUITE CONFIDENT ENOUGH
IN WIND SPEED MEETING WARNING CRITERIA SO HELD OFF ON WATCH FOR THIS
PACKAGE. FEEL MORE CONFIDENT IN ADVISORY WINDS ACROSS THE AREA. SEE
HWO PRODUCT FOR WIND POTENTIAL FOR WED.
AS FAR AS PRECIP GOES THROUGH WEDNESDAY...RAIN ACROSS THE EAST WITH
RAIN SHOWERS ACROSS THE REMAINDER OF THE AREA AHEAD OF THE COLDER
AIR. THROUGH THE AFTERNOON EXPECTING A SLOW CHANGE OVER TO A MIX OF
SNOW. ANY PRECIP ACROSS THE AREA WEDNESDAY NIGHT SHOULD BE ALL SNOW.
AS FAR AS LAKE EFFECT GOES...CONCERNED EARLY ON WITH STRONG WINDS
OVER THE LAKE REDUCING RESIDENCE TIME INHIBITING LAKE EFFECT SNOW.
AS WINDS RELAX A BIT...COMBINED WITH INCREASING LAKE INDUCED CAPE
THE SNOW SHOWERS SHOULD DEVELOP WELL BEGINNING LATER WEDNESDAY
NIGHT.
COLD AIR SETTLES IN ACROSS THE AREA FOR THURSDAY WITH LAKE EFFECT
SNOW SHOWERS LIKELY ACROSS NE OH AND NW PA. TOO FAR OUT TO MENTION
ANY SPECIFICS ON ACCUMS...BUT POTENTIAL FOR ACCUMULATING LAKE EFFECT
SNOW LOOKS GOOD. TEMPERATURES WILL TURN SIGNIFICANTLY COLDER WITH
HIGHS AT BEST IN THE MID 20S. BOTH ECMWF AND GFS SHOWING H850 TEMPS
DROPPING TO -15 TO -20C. HIGH PRESSURE RIDGES INTO THE AREA ON
FRIDAY ALLOWING FOR MUCH OF THE AREA TO REMAIN DRY. THE EXCEPTION
CONTINUES WITH POSSIBLE LAKE EFFECT SNOW SHOWERS. TEMPS WILL NOT
MODERATE VERY MUCH THROUGH THE END OF THE WEEK.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL FINALLY BE SHIFTING EAST OF THE REGION BY
SATURDAY WITH SOUTHERLY WINDS RETURNING. THIS WILL MEAN SLIGHTLY
WARMER AS THE NEXT COLD FRONT APPROACHES WITH HIGHS INTO THE LOWER
30S FOR MOST LOCATIONS. THIS FRONT LOOKS TO ARRIVE ON SUNDAY WITH
SOME SNOW POSSIBLE ALONG AND AHEAD OF IT.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SURFACE TROUGH SWINGING EAST ACROSS LAKE ERIE CAUSING SOME LAKE
ENHANCED SNOW SHOWER ACTIVITY TO MOVE EAST ACROSS CLEVELAND AND
ERIE. ERIE HAS THE HIGHER INTENSITY SNOWFALL WITH VISIBILITIES
DOWN TO AROUND 1 MILE AT TIMES. LAKE SNOW SHOULD START TO KICK IN
AFTER TROUGH MOVES EAST OF THE AREA. AREAS TO THE WEST AND SOUTH
WILL JUST SEE SOME LOW CLOUDS FOR A WHILE WITH IMPROVING
CONDITIONS BY TOMORROW MORNING AND THEN START TO SEE CEILINGS DROP
AGAIN BY TOMORROW EVENING. PROBLEM IN THE END OF THE FORECAST
PERIOD IS THE POTENTIAL FOR SLEET TO MIX WITH THE SNOW AT TOLEDO
AND FINDLAY AS WARM AIR PUSHES NORTH WELL IN ADVANCE OF THE STORM
SYSTEM EXPECTED FOR MID WEEK. WINDS WILL BE SHIFTING TO A
SOUTHEAST TO EASTERLY DIRECTION TOMORROW IN ADVANCE OF THE LOW.
.OUTLOOK...NON VFR LATE TUESDAY AFTERNOON THROUGH THURSDAY. STRONG
WINDS DEVELOPING WEDNESDAY AND CONTINUING INTO THURSDAY.
&&
.MARINE...
AS THE FLOW SHIFTS TO A MORE WESTERLY DIRECTION THIS EVENING...WAVES
COULD BUILD TO 4 FEET IN SOME SPOTS FOR THE NEARSHORE EAST OF
CLEVELAND. ON THE FENCE...BUT FOR NOW PLAN TO HOLD FORECAST TO A 2
TO 4 FOOT RANGE WITH NO SCA BEING PUT UP.
HIGH PRESSURE CROSSES THE LAKE ON TUE FOR LIGHT AND CHANGEABLE FLOW
THAT SHOULD BECOME SE BY TUE NIGHT AND INCREASE AHEAD OF A DEEP LOW
THAT WILL CROSS THE LAKES WEDNESDAY. THIS LOW LOOKS LIKELY TO BRING
HIGH END GALES WED AND WED NIGHT WITH A CHANCE THAT MARGINAL STORM
FORCE WINDS COULD OCCUR. WILL GO WITH A GALE WATCH FOR NOW. WITH THE
WIND DIRECTION AND SPEED...LOW WATER ON THE WEST END OF LAKE ERIE
WILL OCCUR. IT MAY TAKE TO LATE THURSDAY NIGHT OR FRIDAY MORNING FOR
THE WIND SPEEDS TO DROP BELOW GALE FORCE.
HIGH PRESSURE MOVING UP THE OHIO VALLEY FRI NIGHT AND SAT IS
EXPECTED TO GREATLY LESSEN THE FLOW BUT THE MODELS DIFFER ENOUGH SO
THE DIRECTION BY LATER SAT IS IN QUESTION BUT SHOULD GENERALLY BE
WEST OR SW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...GALE WATCH FROM WEDNESDAY MORNING THROUGH LATE THURSDAY NIGHT
FOR LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...ABE
LONG TERM...MULLEN
AVIATION...LOMBARDY
MARINE...ADAMS
