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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 131634
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
1134 AM EST FRI DEC 13 2013

.SYNOPSIS...
HIGH PRESSURE WILL PUSH OFF THE CAROLINA COAST TODAY AS A LOW
PRESSURE SYSTEM ORGANIZES OVER THE SOUTHERN PLAINS. THIS LOW WILL
MOVE FROM THE MIDDLE MISSISSIPPI VALLEY TO THE MIDDLE OHIO VALLEY
TONIGHT INTO SATURDAY...SPREADING RAIN AND SNOW ACROSS THE REGION.
THE LOW WILL WEAKEN AS IT MOVES EAST OF THE AREA SATURDAY NIGHT. A
WEAK RIDGE OF HIGH PRESSURE WILL PUSH INTO THE OHIO VALLEY ON
SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE WILL CONTINUE TO PUSH OFF TO THE EAST THROUGH
THIS AFTERNOON AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
SKIES ARE MOSTLY CLEAR ACROSS THE AREA THIS MORNING BUT EXPECT AN
INCREASE IN CLOUDS THROUGH THIS AFTERNOON AHEAD OF THIS NEXT
SYSTEM. WITH SOME LOW LEVEL WAA...TEMPERATURES WILL PUSH ABOVE
FREEZING ACROSS SOUTHERN PORTIONS OF OUR FA WITH HIGHS RANGING
FROM UPPER 20S NORTH TO UPPER 30S SOUTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
-- Changed Discussion --
AFTER AN EARLY LOOK AT 12Z MODEL GUIDANCE...6 INCHES LOOKS LIKE A
PRETTY GOOD BET ACROSS OUR FAR NORTHWEST COUNTIES. WILL GO AHEAD
AND NUDGE UP SNOW AMOUNTS IN MERCER-AUGLAIZE AND HARDIN COUNTIES
JUST A TAD AND GO AHEAD AND UPGRADE THEM TO A WINTER STORM
WARNING.

...PREV DISCUSSION...

HAVE USED A BLEND OF THE 13.00Z GFS AND ECMWF FOR THE SHORT TERM
FORECAST. THE NAM-WRF APPEARS TOO STRONG WITH THE UPCOMING SURFACE
LOW TO RIPPLE ACROSS THE OHIO VALLEY AND CONTINUES TO GENERATE
HIGHER AMOUNTS OF QPF. THIS IS A TYPICAL BIAS AND HAVE USED THE
MORE CONSISTENT GFS/ECMWF.

FOR TONIGHT AND SATURDAY...AN EMBEDDED S/WV WILL EJECT NORTHEAST
FROM THE SOUTHERN PLAINS TO THE OHIO VALLEY. AS IT DOES...A SFC
LOW WILL ALSO MOVE FROM THE MIDDLE MS VLY TO THE MIDDLE OHIO
VALLEY. DECENT MOISTURE TRANSPORT FROM THE GULF OF MEXICO IN THE
FORM OF ISENTROPIC LIFT WILL SPREAD PCPN FROM WEST TO EAST ACRS
THE AREA OVERNIGHT. COOLING TEMPERATURES OVERNIGHT AND EVAPORATIVE
COOLING SHOULD ALLOW PCPN TO BE MAINLY IN THE FORM OF SNOW NORTH
OF THE OHIO RIVER TONIGHT. FOR POINTS FARTHER SOUTH...A RAIN/SNOW
MIX CAN BE EXPECTED AS TEMPERATURES ONLY DROP INTO THE LOWER 30S.
ON SATURDAY...WIDESPREAD PCPN IS EXPECTED. THERE WILL BE A
TRANSITION TO RAIN ACRS THE FAR SOUTH AS SOME WARM AIR GETS DRAWN
NORTHWARD AHEAD OF THE LOW. FOR POINTS FARTHER NORTH...WE SHOULD
SEE A RIBBON OF RAIN AND SNOW MIXED FOR THE DAYTON/COLUMBUS AREAS
WITH THE NORTHWESTERN CWFA REMAINING ALL SNOW. GIVEN THE CHANGE IN
P TYPE AND THE FAR NW REMAINING ALL SNOW...WE WILL SEE A GRADIENT
IN SNOW ACCUMULATIONS. HAVE ANALYZED MY FORECAST SNOW AMOUNTS TO
SEE IF ANY PLACE IN OUR CWFA WILL HIT WARNING CRITERIA IN EITHER A
12 HOUR OR 24 HOUR TIME FRAME. GIVEN THAT MOST OF THE SNOW WILL
FALL BETWEEN 7 PM FRIDAY AND 7 PM SATURDAY...AM NOT FINDING THESE
VALUES. THUS...THIS SHOULD BE A HIGH END ADVISORY FOR MUCH OF THE
AREA. HAVE DIVIDED THE FORECAST AREA INTO FOUR SECTIONS WITH THE
FAR SOUTH NOT HAVING AN ADVISORY (LITTLE TO UP TO 2 INCHES
EXPECTED)...1-3 INCHES FARTHER NORTH (CINCY METRO)...2-4 INCHES
FOR THE DAYTON/COLUMBUS METRO...AND 4-6 FOR WEST CENTRAL OHIO.

FOR SATURDAY NIGHT...S/WV WILL MOVE NORTHEAST AND DAMPEN AS SFC
LOW WEAKENS AND A COASTAL LOW TAKES OVER OFF THE NEW ENGLAND
COAST. THIS WILL RESULT IN A RAPID DECREASE IN PCPN AND SHOULD
PRETTY MUCH BE OVER BY MID EVENING.

ON SUNDAY...A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE OHIO
VALLEY. CLOUDS WILL LINGER AS MODELS SHOW MOISTURE TRAPPED BELOW
AN INVERSION.

FOR SUNDAY NIGHT INTO MONDAY NIGHT...MODELS DIFFER ON EXACT
PLACEMENT OF WEAK SYSTEMS RIPPLING SOUTHEAST INTO THE GREAT LAKES
WITHIN A NORTHWEST FLOW ALOFT. HAVE TAKEN A BLEND OF THE GFS/ECMWF
WHICH RESULT IN MENTIONING A CHANCE OF SNOW FOR NORTHERN ZONES
THROUGH THE PERIOD.

HIGHS ON SATURDAY WILL RANGE FROM THE LOWER 30S NW TO THE UPPER
30S SOUTHEAST. LOWS SATURDAY NIGHT WILL RANGE FROM THE MID TEENS
NW TO THE UPPER 20S SOUTHEAST. CAA AND CLOUDS WILL ALLOW FOR
LITTLE DIURNAL RECOVERY ON SUNDAY. FOR MONDAY...WE SHOULD SEE A
GRADIENT IN HIGHS RANGING FROM THE MID 20S NORTH TO THE MID 30S
SOUTH.
-- End Changed Discussion --

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST ON
TUESDAY...AND WILL BE PRESENT NEAR THE AREA WEDNESDAY INTO THURSDAY.
THIS WILL BRING DRY CONDITIONS ACROSS THE REGION. SOUTHERLY FLOW
WILL PICK UP ACROSS THE AREA FOR THURSDAY ALLOWING TEMPERATURES TO
WARM INTO THE MIDDLE 30S TO THE LOWER 40S.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
RELATIVELY TRANQUIL CONDITIONS ARE EXPECTED THROUGH THE MAJORITY
OF THE DAY...WITH SOUTHWEST FLOW AT OR BELOW 10 KNOTS...AND
GRADUALLY INCREASING HIGH CLOUDS THROUGH THE AFTERNOON.

HOWEVER...SIGNIFICANT DISRUPTIONS TO FLIGHT CONDITIONS WILL BE
ARRIVING TONIGHT. AS WINDS SHIFT TO THE SOUTH AND EVENTUALLY
SOUTHEAST...SNOW WILL OVERSPREAD THE TAF SITES...WITH IFR
CONDITIONS EXPECTED. BRIEF LIFR CONDITIONS MAY BE POSSIBLE AT
TIMES...ESPECIALLY AT THE NORTHERN TAF SITES. AT THE SOUTHERN TAF
SITES...THERE MAY BE BREAKS IN THE PRECIPITATION EARLY SATURDAY
MORNING...WHICH COULD LEAD TO SOME MVFR PERIODS. HOWEVER...IFR IS
STILL EXPECTED TO BE THE PREVAILING CONDITION THROUGH THIS PART OF
THE FORECAST PERIOD. SOME RAIN WILL EVENTUALLY MIX IN BY SATURDAY
AFTERNOON...WHICH WILL IMPROVE VISIBILITIES SOMEWHAT...THOUGH
CEILINGS ARE EXPECTED TO REMAIN QUITE LOW.

OUTLOOK...IFR CONDITIONS ARE EXPECTED ON SATURDAY AND CONTINUING
INTO SATURDAY NIGHT.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
OH...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 PM EST
     SATURDAY FOR OHZ042>046-051>056-060>065-070>074-077>080-
     082.
     WINTER STORM WARNING FROM 9 PM THIS EVENING TO 7 PM EST
     SATURDAY FOR OHZ026-034-035.
KY...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 PM EST
     SATURDAY FOR KYZ089>093.
IN...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 PM EST
     SATURDAY FOR INZ050-058-059-066-073>075-080.
-- End Changed Discussion --

&&

$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN/JGL
LONG TERM...HICKMAN/NOVAK
AVIATION...HATZOS