525 
FXUS61 KCLE 302023
AFDCLE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
323 PM EST TUE NOV 30 2010

.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA THIS EVENING. THE COLD 
FRONT WILL USHER IN MUCH COLDER AIR TO THE REGION OVER THE NEXT 
SEVERAL DAYS. A TROUGH WILL MOVE EAST ACROSS THE AREA WEDNESDAY 
NIGHT. HIGH PRESSURE WILL BUILD EAST TOWARD THE AREA TOWARD THE END 
OF THE WEEK. 

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE COLD FRONT WILL MOVE EAST ACROSS THE AREA THIS EVENING FORCING 
THE HEAVIER RAIN TO MOVE EAST OF THE AREA. HOWEVER...SOME GOOD UPPER 
LEVEL SUPPORT AND MOISTURE WILL KEEP THE THREAT OF PRECIPITATION 
GOING THROUGH THE NIGHT. AS COLDER AIR WORKS ITS WAY INTO THE 
REGION...THE PRECIPITATION WILL GRADUALLY BECOME MIXED WITH AND 
CHANGE OVER TO SNOW OVER THE WEST HALF OF THE AREA. A MIX OF RAIN 
AND SNOW CAN BE EXPECTED OVER THE EAST HALF WITH MAINLY RAIN OVER 
THE NORTHEAST LAKE SHORE REGION. 

WINDS HAVE ALREADY BEGUN TO SUBSIDE THIS AFTERNOON TO 10 TO 20 MPH 
ACROSS THE AREA. THEREFORE...WILL GO AHEAD AND DROP THE WIND 
ADVISORY AND HIGH WIND WARNING FOR EXTREME NORTHEAST OHIO AND 
NORTHWEST PENNSYLVANIA.

TEMPERATURES DURING THE NIGHT WILL HANG IN THE LOWER 50S AHEAD OF 
THE COLD FRONT BUT WILL CONTINUE TO DROP THROUGH THE 40S INTO THE 
30S FROM WEST TO EAST DURING THE NIGHT BEHIND THE COLD FRONT.

&&

.SHORT TERM /6 AM WEDNESDAY THROUGH 6 AM WEDNESDAY/...
ONCE THE COLDER AIR BECOMES FIRMLY ENTRENCHED OVER THE AREA...THE 
FLOW WILL BECOME WELL ALIGNED OUT OF 240 TO 260 DEGREES AND SET UP A 
LAKE EFFECT SNOW BAND ALONG THE NORTHEAST LAKE SHORE. THE BAND 
APPEARS IT COULD REMAIN PERSISTENT THROUGH THURSDAY NIGHT WHEN HIGH 
PRESSURE BUILDS NORTHEAST INTO THE REGION AND A TROUGH OF LOW 
PRESSURE SWEEPS SOUTHEAST ACROSS THE FORECAST AREA. THIS WILL TURN 
THE WINDS TO A MORE NORTHWESTERLY DIRECTION THURSDAY NIGHT INTO 
FRIDAY.

DUE TO THE PERSISTENT FLOW EXPECTED...IT APPEARS THE COLD AIR 
ADVECTION WILL BE STRONG ENOUGH TO SUPPORT AT LEAST CONDITIONAL 
INSTABILITY BETWEEN THE AIR TEMPERATURE AND WATER TEMPERATURE. THERE 
IS A POSSIBILITY THAT SOME LOCATIONS IN THE HIGHER ELEVATIONS AWAY 
FROM THE LAKE COULD SEE SEVERAL INCHES OF SNOW ON THE GROUND BY 
FRIDAY. THE DURATION OF THE SNOW WILL BE A LONG DRAWN OUT ONE THAT 
CRITERIA FOR A LAKE EFFECT SNOW ADVISORY OR WARNING MAY NOT BE MET 
FOR DURATION.  NEEDLESS TO DAY...WILL STILL HAVE TO MONITOR THE 
SITUATION FOR POSSIBLE WATCHES OR WARNINGS IN THE NEXT 24 HOURS. AT 
THIS TIME...CONFIDENCE IS NOT REAL HIGH ON WHEN AND WHERE THE LAKE 
EFFECT BAND WILL SET UP SO WILL HOLD OFF ON ISSUING A WATCH AT THIS 
TIME. 

A SERIES OF TROUGHS WILL ROTATE ACROSS THE ENTIRE FORECAST AREA TO 
BRING AT LEAST A CHANCE OF SNOW TO THE REST OF THE FORECAST AREA 
EACH PERIOD THROUGH THURSDAY. THREAT FOR THE EXTREME WEST AND SOUTH 
DIMINISHES BY THURSDAY NIGHT AND FRIDAY AS HIGH PRESSURE BUILDS 
TOWARD THE REGION.

WE SHOULD SEE A SURGE OF REINFORCING COLD AIR THROUGH THIS PERIOD TO 
KEEP HIGH TEMPERATURES IN THE LOWER TO MIDDLE 30S TOMORROW AND LOWER 
30S THURSDAY AND FRIDAY. THE COLD AIR ADVECTION WILL ALSO CAUSE LOW 
TEMPERATURES TO DIP INTO THE 20S EACH NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
MODELS TRENDING EVEN WEAKER ON ENERGY THAT WOULD SUPPORT SOME
SNOW ACROSS THE AREA ON SATURDAY. WITH THAT WENT WITH MAINLY
SLIGHT CHANCE POPS ACROSS THE WESTERN HALF OF THE AREA AS WELL AS
FOR SOME LINGERING LAKE EFFECT ACROSS NW PA. GOING INTO EARLY NEXT
WEEK MODELS SHOWING LOW PRESSURE OVER NEW ENGLAND RETROGRADED
WESTWARD BACK NORTH OF THE GREAT LAKES WITH CYCLONIC FLOW
PERSISTING OVER THE REGION. GIVEN THE LITTLE CHANGE IN THE OVERALL
PATTERN TOWARD THE END OF THE PERIOD MADE LITTLE CHANGES TO THE
CURRENT FORECAST. NORTHERLY FLOW OVER LAKE ERIE WILL PERSIST
PROVIDING AT LEAST THE CHANCE FOR SOME LAKE EFFECT SNOW SHOWERS
ACROSS NE OH AND NW PA. TEMPERATURES IN THIS PATTERN WILL REMAIN
MAINLY BELOW NORMAL. GUIDANCE TEMPS TRENDING WELL IN THE BELOW
NORMAL DIRECTION SO SAW LITTLE REASON TO DEVIATE MUCH FROM A BLEND
OF MEX/MOS TEMPS. 
&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
COLD FRONT PUSHING INTO WESTERN OHIO THIS AFTERNOON AND WILL MAKE
GRADUAL PROGRESS EASTWARD THROUGH EARLY TONIGHT. STRONGER LOW
LEVEL WINDS CAUSING SOME WIND SHEAR EARLIER HAVE PUSHED OFF TO THE
NORTHEAST EARLY THIS AFTERNOON SO REMOVED MENTION OF WIND SHEAR IN
TAFS. SURFACE WINDS WILL CONTINUE TO BE GUSTY THIS AFTERNOON AND
EVENING. SOME POCKETS OF VFR...BUT OTHERWISE MAINLY MVFR WITH SOME
PERIODS OF IFR LIKELY AS THE COLD FRONT CROSSES SITES THIS
AFTERNOON AND EVENING. WINDS SHIFTING TO THE SOUTHWEST BEHIND THE
FRONT WITH MAINLY MVFR CIGS LINGERING THROUGH MUCH OF THE TAF
PERIOD. THERE MAY BE SOME IMPROVEMENT DURING THE OVERNIGHT HOURS
AS LOW PRESSURE MOVES WELL OFF TO THE NORTH OF THE REGION...BUT
MVFR CIGS EXPECTED TO RETURN WEDNESDAY MORNING.

.OUTLOOK...MVFR CEILINGS WEDNESDAY WITH SNOW SHOWERS MAINLY NE
OH/NW PA. NON-VFR CONDITIONS ALSO POSSIBLE THURSDAY AND
FRIDAY...ESPECIALLY NE OH/NW PA.

&&

.MARINE...
ENDED THE SMALL CRAFT ADVISORY FOR THE WEST END OF LAKE ERIE.  WINDS 
HAVE DIMINISHED TO 10 TO 20 KNOTS...AND WITH A SOUTH TO SOUTHWEST 
FLOW WAVES WILL REMAIN BELOW 3 TO 5 FEET.  COLD FRONT WILL PUSH 
ACROSS THE LAKE THIS EVENING.  AS IT DOES THE WINDS WILL SHIFT TO 
THE SOUTHWEST.   WILL BE A LITTLE LULL WITH THE WINDS...BUT AS THE 
COLD AIR MOVES OVER THE LAKE WINDS WILL PICK UP TO 15 TO 25 KNOTS 
AGAIN.  AS A RESULT WILL NEED TO KEEP A SMALL CRAFT ADVISORY UP ON 
THE EASTERN PART OF THE LAKE.  WITH LONG WAVE TROUGH REMAINING OVER 
THE LAKE...SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED INTO THURSDAY 
NIGHT.  THINGS FINALLY CALM DOWN ON FRIDAY AS HIGH PRESSURE BUILDS 
IN.

MODELS STILL NOT IN GOOD AGREEMENT WITH THE STRENGTH AND TRACK OR 
EXACT TIMING OF THE NEXT SYSTEM.  SO THERE REMAINS SOME UNCERTAINTY 
WITH THE WEEKEND FORECAST FOR THE WINDS AND WAVES ON LAKE ERIE.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR LEZ146>149.

&&

$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...ABE
AVIATION...ABE
MARINE...DJB