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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 260320
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
1020 PM EST SUN JAN 25 2015

.SYNOPSIS...
THE CENTER OF AN ALBERTA CLIPPER WILL SWING THROUGH KENTUCKY TONIGHT.
THIS WILL BE FOLLOWED BY A WEAK UPPER DISTURBANCE DROPPING ACROSS
THE AREA MONDAY NIGHT INTO TUESDAY MORNING. HIGH PRESSURE WILL
BUILD IN WEDNESDAY...BRINGING QUIET WEATHER FOR MID WEEK BEFORE
YET ANOTHER SYSTEM BRINGS MIXED PRECIPITATION ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
RAIN/SNOW LINE CONTINUES TO MAKE IT WAY SLOWLY SOUTH AND
SOUTHEASTWARD. THE 1304 1000-850MB THICKNESS FROM THE RAP IS
HANDLING THE CHANGEOVER NICELY. STARTING TO SEE SOME BREAKS IN
THE PCPN IN THE WHITEWATER VALLEY AND THE BACKEDGE OF APPROACHING
NE MERCER COUNTY. ONLY MADE A FEW TWEAKS IN THE PCPN FORECAST FOR
TONIGHT. PRETTY MUCH KEPT THE SAME SNOW NUMBERS AND CHANGEOVER
TIMING. DID SPEED UP THE ENDING OF THE SNOW LATE IN THE PERIOD.

COLDER AIR HAS WORKED INTO THE N A LITTLE QUICKER THAN EXPECTED.
KNOCKED A DEGREE OR SO OFF PREVIOUS LOWS TONIGHT.



&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
BECAUSE OF THE AMPLIFICATION AND THEREFOR SLOWER DEPARTURE OF THE
SYSTEM WITH POTENTIAL FOR HIGHER SNOW RATIOS ON THE NW SIDE OF THE
DEPARTING LOW...HAVE LINGERED SNOW ACCUMULATIONS A LITTLE IN AREAS
S/E OF COLUMBUS WITH ADVISORY NOW IN EFFECT UNTIL 15Z AS WELL AS
ADDING A COUPLE OF COUNTIES. SHOULD REMAIN A RUSH HOUR IMPACT IN
ESPECIALLY AREAS EAST/SOUTHEAST OF COLUMBUS.

LINGERING NON-ACCUMULATING SNOW SHOWERS TO LINGER BEHIND THE
SYSTEM IN MAINLY THE FAR EASTERN FCST AREA...THEN WEAK SFC RIDGING
BUILDS IN TO THE WEST IN THE 21Z-00Z TIMEFRAME. ONLY LOCATION TO
RECEIVE SOME PARTIAL CLEARING WILL BE IN THE FAR NW AS MID/HIGH
CLOUDS BUILD IN FROM ADVANCING WEAK S/WV FROM THE NORTHERN PLAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE GFS/NAM HAVE TRENDED A LITTLE FARTHER WEST IN REGARDS TO A WEAK
S/WV DROPPING SOUTHEAST INTO THE MIDDLE OHIO VALLEY MONDAY NIGHT
INTO TUESDAY. AS SUCH...IT NOW APPEARS THAT THE CHANCE OF LIGHT SNOW
WITH THIS FEATURE MAY JUST GRAZE OUR FAR WEST/SOUTHWEST. HAVE
ADJUSTED THE FORECAST TO REFLECT THIS. THERE WILL BE CONSIDERABLE
CLOUDINESS THROUGH THE PERIOD.

HIGH PRESSURE WILL BRIEFLY BUILD INTO THE AREA TUESDAY NIGHT INTO
WEDNESDAY. COLD TEMPERATURES ON TUESDAY WILL MODIFY SOME BY
WEDNESDAY.

FOR THE PERIOD WEDNESDAY NIGHT INTO THURSDAY NIGHT...THE ECMWF AND
THE GFS DIFFER IN THE TIMING OF A TANDEM OF S/WVS TO AFFECT THE
REGION...ALONG WITH AN ASSOCIATED LOW PRESSURE/COLD FRONT. THE ECMWF
IS SLOWER AND SHARPER WITH THE SECOND S/WV WHILE THE GFS IS FASTER.
HAVE GONE WITH THE GFS TIMING AT THIS TIME TO KEEP CONTINUITY FROM
PREVIOUS FORECAST. WITH RETURN FLOW...TEMPERATURES WILL BEGIN TO
WARM SOME LATE WEDNESDAY NIGHT INTO THURSDAY. THERE WILL BE A RACE
BETWEEN HOW FAST IT WARMS COMPARED TO WHEN THE ONSET OF PCPN BEGINS.
AS STATED YESTERDAY...IT LOOKS LIKE THERE WILL BE SOME MIXED PCPN
(-FZRA/-PL/-SN) EARLY ON BEFORE IT BECOMES RAIN/SNOW MIXED NORTH AND
RAIN SOUTH BY THURSDAY AFTERNOON. GIVEN THAT THIS IS FOUR DAYS OUT
AND IT IS HARD TO PINPOINT THE CHANGING THERMAL FIELDS EVEN IN THE
SHORT TERM...HAVE CONTINUED WITH RAIN/SNOW WORDING ATTM. PCPN SHOULD
CHANGE BACK TO SNOW THURSDAY NIGHT BEFORE ENDING BY FRIDAY MORNING.

FOR FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE WILL ONCE AGAIN BUILD
INTO THE REGION. TEMPERATURES WILL COOL BACK DOWN TO BELOW SEASONAL
NORMALS.

LONG RANGE MODELS DISAGREE ON HOW FAST A MAJOR WEATHER PATTERN
CHANGE WILL OCCUR OVER THE WEEKEND INTO NEXT WEEK AS MUCH COLDER
ARCTIC AIR PLUNGES SOUTHEAST INTO THE GREAT LAKES AND THE OHIO
VALLEY. HAVE SIDED WITH THE ECMWF ATTM WHICH PUSHES AN ARCTIC FRONT
INTO THE REGION DURING THE SATURDAY/SUNDAY TIME FRAME. WILL FORECAST
A CHANCE OF SNOW WITH THIS SYSTEM.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
CLIPPER SYSTEM CONTINUES TO AFFECT THE TAFS. RAIN-SNOW LINE WAS
NORTH OF KDAY-KCMH LINE FOR MUCH OF THE AFTN BUT HAS SAGGED SOUTH
OF THEM IN THE PAST FEW HOURS CHANGING THE PCPN TO SNOW. NRN TAFS
WILL EXPERIENCE PERIODS OF IFR CIGS AND VSBYS OVER THE NEXT 6
HOURS OR SO.

FOR THE SRN TAFS...THE 1000-850MB CRITICAL THICKNESS WILL FALL OVERNIGHT.
MODELS HAVE IT REACHING CVG-LUK-KILN AROUND 05Z. RAIN WHICH IS
CURRENTLY FALLING IN THOSE LOCATIONS WILL CHANGE TO SNOW FOR A
COUPLE OF HOURS BEFORE ENDING.

CIGS ARE EXPECTED TO RECOVER TO MVFR AS THE SNOW COMES TO AN END
FROM WEST TO EAST BEGINNING AROUND 08Z IN THE W....BUT NOT UNTIL
AFTER 12Z IN THE E.

WINDS WILL TURN NLY AT 13-15KT AND WILL GUSTS 20-25KT OVERNIGHT AS
THE COLD AIR WORKS IN FORM THE N. GUSTS SHOULD TAPER OFF AFTER
SUNRISE MONDAY.

LOW CIGS ARE EXPECTED TO LINGER FOR MUCH OF THE
MORNING...SCATTERING OUT IN THE WRN TAFS AROUND 18Z.


OUTLOOK...MVFR CIGS AND VSBYS POSSIBLE THURSDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR OHZ026-034-
     035.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR OHZ042>046-
     051>055-060>064-072.
     WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ056-065-
     073-074.
KY...NONE.
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ050.

&&

$$
SYNOPSIS...JDR
NEAR TERM...SITES
SHORT TERM...JDR
LONG TERM...HICKMAN
AVIATION...SITES