FXUS61 KCLE 062240
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
540 PM EST SUN DEC 6 2009
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL MOVE TO THE EAST
COAST TONIGHT. A WEAK LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
SOUTHERN GREAT LAKES ON MONDAY...FOLLOWED BY MORE HIGH PRESSURE ON
TUESDAY. A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO IMPACT THE
REGION WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HIGH PRESSURE WILL SLIDE OFF TO THE EAST TONIGHT TOWARDS THE MID
ATLANTIC COAST. LAKE EFFECT SNOW SHOWERS HAVE DIMINISHED. THE MAIN
WEATHER FOCUS OVERNIGHT WILL BE LOW TEMPS ACROSS THE AREA. WHILE
MANY INTERIOR LOCATIONS GOT DOWN INTO THE TEENS THIS MORNING...20S
ALONG THE LAKESHORE. MID AND HIGH CLOUDS ADVANCING NORTHEAST THIS
AFTERNOON ARE EXPECTED TO BUILD OVER THE AREA THIS EVENING AND
TONIGHT. THESE CLOUDS MAY BE JUST ENOUGH TO KEEP MINS TONIGHT
SLIGHTLY MILDER THAN LAST NIGHT. BOTH MET AND MAV NUMBERS PRETTY
CLOSE FOR TONIGHT SO WENT WITH A BLEND OF THEM.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEAK LOW PRESSURE PUSHES ACROSS SOUTHERN GREAT LAKES THROUGH MONDAY.
HOWEVER...GUIDANCE POPS FROM BOTH NAM AND GFS SHOWING AT MOST LOW
CHANCE FOR NORTHERN AREAS WITH SLIGHT CHC ACROSS THE SOUTHERN HALF.
TEMPS ARE EXPECTED TO CLIMB INTO THE MID TO UPPER 30S ACROSS THE
AREA. WENT A BIT COOLER THAN GUIDANCE GIVEN PLENTY OF CLOUD COVER.
H850 TEMPS WELL BELOW FREEZING AS WELL AS 1000-850 THICKNESSES
REMAINING BELOW 1300 SO THINKING THAT ANY PRECIP THAT DOES REACH THE
GROUND WILL BE IN THE FORM OF SOME WET SNOW. DIDN/T PUT ANY
ACCUMULATION IN GRIDS GIVEN LACK OF POPS AS WELL AS GROUND TEMPS.
WINDS TURNING NW OFF THE LAKE BEHIND LOW PRESSURE MONDAY NIGHT.
CONFINED CHC POPS FOR LAKE EFFECT SNOW SHOWERS ACROSS FAR NE OH AND
INTO ALL OF NW PA. INVERSION COMES UP A BIT CLOSER TO 8K FT BY THEN.
HIGH PRESSURE BUILDS ACROSS THE AREA ON TUESDAY AND THEN SLIDES TO
THE EAST THROUGH THE DAY. THIS WILL REDUCE FLOW OVER THE LAKE AND
THEN SHIFT WINDS TO THE SOUTHEAST LATER IN THE AFTERNOON THUS
BRINGING AN END TO THE LAKE EFFECT.
BEGINNING TUESDAY EVENING THE REGION WILL SHIFT INTO A WARM AIR
ADVECTION PATTERN. COLDER AIR WILL BE LOCKED IN AT THE SURFACE SO
NOT EXPECTING HIGHS TO WARM UP TOO QUICKLY...BUT TEMPS ALOFT WILL BE
GRADUALLY WARMING LATE TUESDAY AND THROUGH TUESDAY NIGHT. HAVE NON
DIURNAL TEMP TRENDS IN GRIDS FOR THEN.
LOOKS LIKE THE SIGNIFICANT WEATHER FEATURE OF THE WEEK WILL IMPACT
THE REGION COME WEDNESDAY. GFS...ECMWF...CANADIAN ALL CONSISTENT
BRINGING STRONG LOW PRESSURE NORTHEAST THROUGH THE CENTRAL GREAT
LAKES KEEPING THE SYSTEM WEST OF THE REGION. CONCERN WITH THIS
SYSTEM IN TWO ASPECTS. FIRST...WITH COLDER AIR LOCKED IN AT LOW
LEVELS BROUGHT MIXED PRECIP INTO THE AREA TUESDAY NIGHT. PRECIP
TYPES WILL HAVE TO BE REFINED A BIT OVER TIME...BUT FAIRLY CONFIDENT
THAT THE WESTERN THIRD OF THE REGION WILL SEE A QUICK TRANSITION
OVER TO RAIN. NE OH AND NW PA ARE TRICKIER WITH COLDER AIR LOCKED IN
BETTER THERE SO MIXED PRECIP POTENTIAL HIGHER FROM ABOUT CLE-MFD-YNG
AND NORTHEAST. SECOND...WINDS WILL BE THE OTHER SIGNIFICANT ISSUE WITH
BOTH NAM AND GFS SHOWING POTENTIAL FOR 60KT AT H850 MOVING THROUGH
THE AREA ON WEDNESDAY. WHILE THIS IS STILL A FEW DAYS OUT...ALREADY
INDICATED SUSTAINED WINDS 20-30KT IN GRIDS.
COLDER AIR QUICKLY MOVES IN BEHIND LOW PRESSURE WEDNESDAY NIGHT. GFS
A BIT QUICKER WEDNESDAY NIGHT BUT ECMWF CATCHES UP BRINGING H850
TEMPS DOWN TO -15 TO -20C FOR THURSDAY MORNING. HIGHS ON THURSDAY
ARE ONLY EXPECTED TO BE IN THE 20S AREA WIDE WITH LAKE EFFECT
SNOW SHOWERS LIKELY ACROSS NE OH/NW PA CONTINUING THROUGH THURSDAY
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE BUILDS ACROSS THE MIDDLE ATLANTIC COAST IN THE WAKE OF
THE MID WEEK STORM SYSTEM. THIS WILL LEAVE A WESTERLY WIND ACROSS
LAKE ERIE WITH SOME LAKE EFFECT SNOWS CONTINUING UNTIL EARLY
SATURDAY. TEMPERATURES WILL REMAIN BELOW AVERAGE FOR FRIDAY INTO
SATURDAY WITH MOST LOCATIONS REMAINING BELOW FREEZING.
UNCERTAINTY ON A STORM THAT LOOKS TO MOVE UP THE EAST COAST FOR THE
END OF NEXT WEEKEND. HAVE NOT GONE ANYTHING MORE THAN A SLIGHT
CHANCE IN THE GRIDS WHICH WILL NOT BE MENTIONED IN THE ZONES.
REMAINING BELOW AVERAGE ON TEMPERATURES INTO SUNDAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
CONTINUED WITH VFR CONDITIONS THROUGH THE PERIOD ALTHOUGH IT MAY
BE CLOSE IN THE WEST TOWARDS 22-24Z IN THE WEST. FOR THE EVENING
AND OVERNIGHT HIGH LEVEL MOISTURE WILL CONTINUE TO INCREASE AND
THICKEN AHEAD OF LOW PRESSURE MOVING TOWARD THE MISSISSIPPI VALLEY.
FOLLOWING THE NAM12...DEEP MOISTURE REACHES INTO THE AREA AFTER
ABOUT 22Z MONDAY WITH 5KFT RH REACHING 95%. BROUGHT IN THE CEILING
AROUND 45 HUNDRED FEET WEST HALF AFTER 20Z AND ALSO BROUGHT IN
THE POSSIBILITY OF A (SNOW) SHOWER AS FAR EAST AS KCLE. WITH ANY
SNOW SHOWERS IN THE WEST CONDITIONS COULD DIP TO MVFR BUT FOR NOW
WILL ONLY HAVE VCSH GIVEN LOW PROBABILITY.
.OUTLOOK...NON VFR MONDAY EVENING AND AGAIN TUESDAY NIGHT THROUGH
THURSDAY. STRONG WINDS WEDNESDAY INTO THURSDAY.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO MOVE EASTWARD TONIGHT AS LOW PRESSURE
TAKES SHAPE OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. STILL MAY BE
SOME SLIGHTLY STRONGER WINDS OVER THE EASTERN THIRD OF THE LAKE
WHERE THE TIGHTER PRESSURE GRADIENT WILL EXIST. SO MAY GET SOME
WAVES AROUND 3 FEET INTO THE EVENING BUT LOOKS AS IF WIND SPEEDS
WILL REMAIN UNDER 20 KNOTS.
LOW PRESSURE WILL TRACK THROUGH THE CENTRAL LAKES ON MONDAY DRAGGING
A WEAK COLD FRONT ACROSS LAKE ERIE. AS WINDS BECOME SWING TO THE
WEST IN THE WAKE OF THE FRONT THEY MAY INCREASE TO AROUND 20 KNOTS.
WILL HAVE TO WATCH WAVE CONDITIONS BY MONDAY AFTERNOON AND MAY NEED
A SMALL CRAFT ADVISORY FOR THE LATE AFTERNOON INTO THE OVERNIGHT.
THE MAIN WEATHER STORY FOR THE WEEK WILL BE THE STRONG STORM SYSTEM
THAT WILL TRACK ACROSS THE CENTRAL GREAT LAKES. SOUTHERLY WINDS IN
ADVANCE OF THIS STORM SYSTEM WILL INCREASE SIGNIFICANTLY. HOWEVER
THE STRONGEST WINDS WILL LIKELY OCCUR AS THE COLD FRONT SWEEPS
ACROSS THE LAKE ON WEDNESDAY AFTERNOON AND EVENING. SW TO W WINDS
WILL INCREASE TO AT LEAST GALE CONDITIONS AND ARE STARTING TO LOOK
AS IF STORM CONDITIONS MAY BE REACHED. IF THESE STRONG SW TO W WINDS
MATERIALIZE THEN THERE WILL BE SOME LOW WATER ISSUES IN THE TOLEDO
AREA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...MULLEN
AVIATION...TK
MARINE...MULLEN
