823
FXUS61 KCLE 162001
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
401 PM EDT WED OCT 16 2013
.SYNOPSIS...
LOW PRESSURE LOCATED NORTH OF LAKE HURON WILL TRACK NORTHEAST ACROSS
QUEBEC ON THURSDAY WHILE A TROUGH LINGERS ACROSS THE GREAT LAKES
REGION. HIGH PRESSURE WILL BUILD OVER THE OHIO VALLEY ON THURSDAY
NIGHT AND FRIDAY. ANOTHER TROUGH WILL MOVE INTO THE GREAT LAKES
REGION ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
COLD FRONT BISECTS THE AREA THIS AFTERNOON BUT HAS BEEN MAKING SLOW
EASTWARD PROGRESS AS WE REMAIN ENTRENCHED IN DEEP SOUTHWESTERLY FLOW
ON THE LEADING EDGE OF A BROAD LONGWAVE TROUGH. SHOWERS AND A FEW
THUNDERSTORMS HAVE DEVELOPED ALONG THE FRONT FROM ASHTABULA TO MOUNT
VERNON AND WILL BRING ONE MORE ROUND OF RAIN TO MOST LOCATIONS AS IT
MOVES EAST THROUGH 01Z. SOME OF THE SHOWERS ARE PRODUCING HEAVY
BURSTS OF RAIN BUT WILL BE SHORT LIVED THIS EVENING.
THE SURFACE LOW LOCATED NORTH OF LAKE HURON WILL MOVE NORTHEAST INTO
QUEBEC OVERNIGHT WITH LOW LEVEL FLOW FINALLY SHIFTING TO MORE
WESTERLY. THE COOLER AIR WILL FINALLY OVERSPREAD THE AREA TONIGHT
WITH 850MB TEMPERATURES OF 4-5C OVER LAKE ERIE. WE HAVE BEEN
WATCHING THE STRATUS DECK ASSOCIATED WITH THE COLD POOL APPROACH
FROM THE WEST ON VISIBLE SATELLITE. THE STRATUS WILL LIKELY EXPAND
INTO NW OHIO AND OVER LAKE ERIE BUT WILL STRUGGLE TO OVERSPREAD THE
REST OF THE AREA WITH A WEDGE OF VERY DRY AIR PRECEDING IT. IT WILL
TAKE UNTIL AFTER MIDNIGHT AND LIKELY MORE LIKE 3-4 AM FOR LAKE
EFFECT SHOWERS TO START TO DEVELOP. GIVEN THE SOUTHWESTERLY FLOW
OVER THE LAND AND TROFINESS OVER THE LAKE...ANY SHOWERS THAT DO
DEVELOP WILL LIKELY BE OUT OVER THE LAKE...AND WILL CONFINE ANY LOW
CHANCE POPS TO THE SHORELINE. TEMPERATURES ARE A LITTLE TRICKY
OVERNIGHT WITH VARIABLE CLOUDINESS AS CLOUDS ATTEMPT TO CLEAR FROM
THE WEST BUT AT LEAST PARTIALLY FILL BACK IN OVERNIGHT. WENT WITH
FORECAST LOWS IN THE LOW TO MID 40S INLAND...HOLDING CLOSER TO 50
NEAR THE LAKE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
WE REMAIN IN AN ACTIVE PATTERN THROUGH THE SHORT TERM AS A SERIES OF
SHORTWAVES LIFT ACROSS THE AREA IN ADVANCE OF A DEEP TROUGH
TAKING SHAPE OVER THE PLAINS/UPPER MIDWEST. TEMPERATURES WILL FALL
BELOW NORMAL WITH COLD ADVECTION CONTINUING ON THURSDAY AND
ANOTHER SHOT OF COOLER AIR ARRIVING BEHIND A FRONT ON SATURDAY.
THE UPPER LEVEL TROUGH SEEN ON WATER VAPOR IMAGERY IN THE LEE OF THE
ROCKIES TODAY WILL CURL NORTHEAST AND MOVE ACROSS THE AREA THURSDAY
AFTERNOON. FAVORABLE INSTABILITY WILL DEVELOP ABOVE 650MB WITH THE
APPROACH OF THE COLD POOL ALOFT BRINGING A GOOD OPPORTUNITY FOR
SHOWERS. MOST LOCATIONS WILL SEE A PERIOD RAIN ON THURSDAY AFTERNOON
BUT EXPECT THE DURATIONS TO ONLY LAST A FEW HOURS. MOSTLY CLOUDY
SKIES AND SHOWERS WILL KEEP HIGH TEMPERATURES COOL IN THE UPPER 50S.
HIGH PRESSURE WILL EXPAND NORTHEAST UP THE OHIO VALLEY FROM THURSDAY
NIGHT INTO FRIDAY WITH THE AIRMASS DRYING OUT. SKIES WILL ATTEMPT TO
CLEAR FROM THE SOUTH ON FRIDAY BUT EXPECT SCATTERED CU TO LINGER IN
MOST AREAS WITH STEEP LOW LEVEL LAPSE RATES.
THE UPPER LEVEL TROUGH STRENGTHENS OVER THE PLAINS ON FRIDAY AS THE
NEXT SURGE OF COLD AIR PLUNGES SOUTH OUT OF CANADA. LARGE SCALE
ASCENT INCREASES AGAIN ON SATURDAY BRINGING ANOTHER ROUND OF SHOWERS
AS THE TROUGH PIVOTS ACROSS THE GREAT LAKES REGION. COLD ADVECTION
WILL RESUME ON FRIDAY NIGHT AND SATURDAY AND LOWERED HIGHS TO THE
LOW AND MID 50S ON SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A CONTINUED UNSETTLED PATTERN AND AS USUAL SOME MODEL DIFFERENCES. A
COLD FRONT AND OR TROFS WILL BE MOVING THROUGH AT TIMES THROUGH THE
PERIOD. THE GFS MOVES A COLD FRONT THROUGH ON SUNDAY. ANOTHER COLD
FRONT MOVES THROUGH MONDAY AND THEN ON WEDNESDAY. A COLD UPPER TROF
CONTINUES OVER THE AREA. CONTINUED TIMING DIFFERENCE. THE BEST AREA
THAT WILL HAVE SHOWERS WILL BE THE SNOW BELT AREAS...HOWEVER...MUCH
OF THE FORECAST AREA WILL HAVE A CHANCE OF SHOWERS DEPENDING ON THE
STRENGTH OF THE TROF/FRONT. USED A BLEND OF WPC GUIDANCE FOR THE
TEMPERATURE FORECAST.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT 18Z THE COLD FRONT WAS LOCATED FROM NEAR CLE TO MFD AND SOME
SHOWERS WERE ALONG IT. MAINLY MVFR CONDITIONS ARE EXPECTED AHEAD
OF AND JUST BEHIND IT. AN AREA OF HARDILY ANY CLOUDS IS ALSO
BEHIND THE FRONT THAT WILL MOVE EAST THROUGH THE EVENING. THE
LEADING EDGE OF AN AREA OF STRATUS LOCATED FROM NEAR DETROIT TO
FORT WAYNE SHOULD CONTINUE TO MOVE EAST. THE EASTWARD PROGRESS HAS
SLOWED DOWN. THE MODELS ARE NOT SURE IT WILL MOVE ACROSS THE WHOLE
FORECAST AREA BUT IT IS SUCH A LARGE AREA OF STRATUS AND WITH A
WESTERLY FLOW AND NIGHTTIME THAT ALWAYS HELP THE LOW CLOUDS TO
CONTINUE TO SPREAD AND OR EXPAND. MODERATE CONFIDENCE IN
FORECASTING MVFR CEILINGS TO SPREAD WEST TO EAST AFTER DARK. AFTER
DARK IT SHOULD BE MAINLY DRY.
A SURFACE AND UPPER TROF WILL AFFECT THE AREA ON THURSDAY WITH
WIDESPREAD SHOWERS AND MVFR CONDITIONS DEVELOPING FROM THE WEST BY
NOON THURSDAY.
OUTLOOK...NON-VFR LIKELY AT TIMES THURSDAY EVENING INTO FRIDAY
MORNING MAINLY ACROSS NE OH/NW PA. NON-VFR CONDITIONS WILL LIKELY
REDEVELOP SATURDAY WITH THE NEXT COLD FRONT.
&&
.MARINE...
CONTINUING THE SMALL CRAFT ADVISORY ON BOTH ENDS OF THE LAKE. ON THE
EDGE ABOUT THE WEST END. ON THE WEST END IT IS MAINLY FOR WIND
SPEEDS OF 15 TO 25 KNOTS. IT IS CLOSE BUT WITH THE COLD ADVECTION
WILL CONTINUE THE ADVISORY. THE WINDS ARE JUST STARTING TO PICK UP
ON THE EAST END OF THE LAKE AS THE FRONT IS MOVING THROUGH.
THIS WILL BE A VERY UNSETTLED PATTERN ON THE LAKE WITH A THREAT OF
SMALL CRAFT ADVISORIES AT TIMES THROUGH THE MIDDLE OF NEXT WEEK. IT
ALL DEPENDS ON THE TIMING OF THE TROFS/COLD FRONTS AS THEY MOVE
THROUGH. MARINERS WILL NEED TO MONITOR THE FORECASTS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THURSDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA