-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 282200 CCA
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
ISSUED BY NATIONAL WEATHER SERVICE JACKSON KY
341 PM EST WED JAN 28 2015

.SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL APPROACH TONIGHT AND MOVE THROUGH THE REGION ON
THURSDAY. THIS SYSTEM WILL BRING A THREAT OF WINTRY PRECIPITATION AT
LEAST AT THE ONSET IN SOME LOCATIONS. AS THE LOW PRESSURE SYSTEM
DEPARTS...ANY LINGERING SHOWERS SHOULD TURN TO SNOW SHOWERS FROM
LATE THU AFTERNOON INTO THURSDAY EVENING. HIGH PRESSURE WILL BEGIN
TO BUILD BACK INTO THE AREA ON FRIDAY AND REMAIN IN CONTROL OF THE
WEATHER INTO THE START OF THE WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...

DRY CONDITIONS ARE EXPECTED INITIALLY DUE TO HIGH PRESSURE THAT
WILL BEGIN TO DEPART THE REGION. SATELLITE IMAGERY AND MODEL DATA
CONTINUE TO SUGGEST AN INCREASE IN HIGH CLOUDS THROUGH THE EVENING
AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.

IT STILL APPEARS THAT TEMPERATURES WILL GENERALLY BE STEADY
DURING THE EVENING HOURS WITH GUIDANCE SUGGESTING MIN TEMPERATURES
AROUND MIDNIGHT IN MANY LOCATIONS OUTSIDE OF ANY DECOUPLED VALLEYS
IN EASTERN AND SOUTHEAST PART OF THE CWA. SOUTHERLY FLOW WILL
INCREASE TONIGHT. AS SOUTHERLY FLOW INCREASES TEMPERATURES WILL
BEGIN TO SLOWLY RISE THROUGH THE OVERNIGHT HOURS.

PRECIPITATION WILL HOLD OFF FOR MOST OF THE OVERNIGHT HOURS. THERE
IS ENOUGH CONCERN FOR SOME OF THIS TO REACHING THE GROUND TOWARD
DAWN THAT A FREEZING RAIN ADVISORY IS PLANNED FOR THE NORTHERN
TIER OR TWO OF COUNTIES...THOUGH MOST OF THIS SHOULD HOLD OFF
UNTIL THE SHORT TERM PERIOD.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...

-- Changed Discussion --
IN THE SW PART OF THE AREA...EXPECT TEMPERATURES TO ALREADY BE
NEAR OR ABOVE FREEZING TO START THE PERIOD AND THE PRECIPITATION
WILL LIKELY JUST BEGIN AS RAIN. HOWEVER...THERE IS SOME
UNCERTAINTY WITH THE TIME OF ARRIVAL OF PRECIPITATION AS THE GFS
SATURATES THIS AREA A BIT QUICKER AND THE TOP DOWN APPROACH WOULD
SUGGEST THE POSSIBILITY OF A MIX AT ONSET THERE AS WELL.

THE CHANCES FOR A MIX AT ONSET ARE BETTER FURTHER TO THE NORTH
AND EAST AS THE INITIALLY DRY AIRMASS WILL BE ABLE TO WET BULB AND
FREEZING RAIN OR SLEET WOULD BE POSSIBLE FOR A LONGER PERIOD OF
TIME...BUT THIS PRECIPITATION WOULD BE VERY LIGHT. IN THIS
AREA...THERE WILL BE A BRIEF WINDOW FOR A COUPLE OF HOURS WHERE
TEMPERATURES COULD BE AT OR JUST BELOW FREEZING AS PRECIPITATION
MOVES INTO THE AREA. DUE TO THIS...A BRIEF PERIOD OF FREEZING RAIN
WILL BE POSSIBLE CONSIDERING THE COLD AND INITIALLY FROZEN OR SNOW
COVERED GROUND IN PLACE PARTICULARLY ACROSS THE NORTH AND
NORTHEASTERN PART OF THE AREA DUE TO THE RECENT COLDER WEATHER. ANY
PRECIPITATION THAT REACHES THE GROUND BEFORE MID MORNING IN THE FAR
NORTH AND EAST COULD LEAD TO SOME IMPACTS OF SLICK OR ICY SPOTS ON
UNTREATED OR SECONDARY ROADS...BRIDGES...OVERPASSES AND WALKWAYS
DURING THE MORNING...SO A FREEZING RAIN ADVISORY HAS BEEN ISSUED FOR
THE NORTHERN TIER OR TWO OF COUNTIES TO INCLUDE THE COLUMBUS METRO
AREA. ANY FREEZING RAIN IS EXPECTED TO BE LIGHT...BUT STILL A
POTENTIAL THREAT. AS FOR THE HWO...WE PLAN TO CONTINUE TO MENTION
FREEZING RAIN OR MIX AT ONSET FOR THE SOUTHWEST THREE QUARTERS OF
THE AREA.

WARMER AIR WILL CONTINUE TO SURGE INTO THE AREA BY MID TO LATE
THURSDAY MORNING AND AS IT DOES TEMPERATURES WILL RISE ABOVE
FREEZING ACROSS THE ENTIRE FA AHEAD OF THE COLD FRONT. THIS COLD
FRONT MOVE THROUGH THE FA DURING THE AFTERNOON AND EARLY EVENING
HOURS ON THURSDAY BRINGING ADDITIONAL PRECIPITATION CHANCES TO THE
AREA. AS THE COLDER AIR BEGINS TO WORK INTO THE REGION LATER IN
THE AFTERNOON AND EVENING...PRECIPITATION WILL CHANGEOVER TO SNOW
SHOWERS FROM NORTH OR NORTHEAST TO SOUTHEAST. THE CHANCES FOR
LIGHT SNOW SHOWERS WILL CONTINUE THURSDAY NIGHT AND POSSIBLY INTO
EARLY ON FRIDAY DUE TO A COMBINATION OF A WEAK DISTURBANCE PASSING
THROUGH AND WINDS OFF OF LAKE MICHIGAN. SNOWFALL ACCUMULATION FROM
THIS IS STILL EXPECTED TO LIGHT AND AN INCH OR LESS.

HIGH PRESSURE WILL BEGIN TO WORK INTO THE FA LATER FRIDAY
AFTERNOON INTO FRIDAY NIGHT. CLOUD COVER WILL DECREASE THROUGH THE
NIGHT FRIDAY NIGHT AND WINDS WILL BE LIGHT. WITH THIS COMBINATION
EXPECT TEMPERATURES TO DROP DOWN INTO THE SINGLE DIGITS TO THE
TEENS ACROSS THE FA.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

-- Changed Discussion --
SURFACE HIGH PRESSURE PASSING NW TO SE OVER THE REGION AT THE START
OF THE PERIOD WILL PROVIDE CLEAR TO PARTLY CLOUDY SKIES AND COLD
TEMPERATURES FRIDAY NIGHT AND SATURDAY. AFTER THIS...THE FORECAST
TROUBLES BEGIN. AN UPPER LEVEL TROUGH ABOUT TO MOVE ONSHORE ON THE
WEST COAST WILL CLOSE OFF A LOW OVER THE SW CONUS LATE IN THE WEEK.
AN UPPER LEVEL IMPULSE SHOULD THEN DROP SE OUT OF CANADA ACROSS THE
GREAT PLAINS THIS WEEKEND. THE DEGREE TO WHICH THIS PHASES WITH THE
UPPER LOW/RESIDUAL TROUGH OVER THE SW CONUS IS STILL UNCERTAIN. THE
EVENTUAL TRACK AND STRENGTH OF THE UPPER LEVEL SYSTEM WILL AFFECT
SUBSEQUENT SURFACE LOW DEVELOPMENT IN THE EASTERN CONUS. A WIDE
RANGE OF TRACKS AND STRENGTHS OF SURFACE SYSTEMS HAS BEEN OBSERVED
IN THE MODELS IN RECENT DAYS...WITH THE GFS AND ECMWF SHOWING BOTH
RUN TO RUN AND MODEL TO MODEL INCONSISTENCIES...AND NO CONSENSUS
YET. THE LATEST 12Z RUNS HAVE GENERALLY TRENDED WEAKER WITH THE
SYSTEM. BOTTOM LINE...THERE IS STILL A LARGE DEGREE OF UNCERTAINTY
REGARDING THE FORECAST DURING THIS PERIOD. AT THIS POINT THE
FORECAST IS STILL ONE OF LOW CONFIDENCE...AND IS BASED ON A BLEND OF
RECENT MODEL RUNS. THE PRECIP THREAT WILL BE FROM SATURDAY NIGHT
INTO SUNDAY NIGHT...AND MAINLY IN THE FORM OF SNOW. HAVE ALLOWED FOR
A POTENTIAL MIX WITH RAIN IN SOUTHERN OH AND NORTHERN KY.

IN THE WAKE OF THE WEEKEND SYSTEM...HIGH PRESSURE WITH ANOTHER
ARCTIC AIR MASS IS EXPECTED TO MOVE IN FROM THE NW AND DOMINATE
THROUGH TUESDAY. ON WEDNESDAY...ANOTHER LARGE SCALE UPPER TROUGH
BEGINS TO DEEPEN AS IT MOVES IN FROM THE NW...AND LOW LEVEL WARM AIR
ADVECTION BEGINS IN ADVANCE OF IT. TIMING OF WEAK UPPER LEVEL
IMPULSES IN THAT TIME FRAME WOULD BE A GUESS AT THIS POINT...BUT
SOME MODEL RUNS HAVE SHOWN A POTENTIAL FOR A BIT OF SNOW...AND HAVE
USED A 20 PERCENT POP ON WEDNESDAY.
-- End Changed Discussion --

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BRING INITIAL VFR WHICH SHOULD PREVAIL IN MOST
LOCATIONS THROUGH AT LEAST 12Z ON THU. HIGH CLOUDS SHOULD
OVERSPREAD BY THIS EVENING AND OVERNIGHT WITH A MID DECK TO
FOLLOW...MOVING IN AFTER 9Z ON THU.

OUTLOOK...FROM 11Z TO 17Z ON THU...MVFR CIGS AND OR VIS SHOULD
DEVELOP AND SOME AT LEAST BRIEF PERIODS OF IFR CEILINGS AND VIS
ARE POSSIBLE 18Z THU THROUGH AT LEAST 12Z FRI. A GRADUAL
IMPROVEMENT TO VFR SHOULD OCCUR IN ALL AREAS 9Z TO 15Z FRI WITH
THE VFR CONTINUING INTO SUNDAY. AT THE ONSET OF THE PRECIPITATION
ON THU...A PERIOD OF FREEZING RAIN WILL BE POSSIBLE GENERALLY
NORTH OF THE OH RIVER OR MAINLY FOR LOCATIONS NORTH AND EAST OF
LUK AND CVG. CEILINGS AND VISIBILITIES ARE ANTICIPATED TO
DETERIORATE AGAIN ON SUNDAY...TO MVFR AND THEN TO IFR AND PERHAPS
AIRPORT MINS BY SUNDAY EVENING.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY FROM 4 AM TO 11 AM EST THURSDAY FOR
     OHZ026-034-035-043>046-052-054>056-065.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...JP
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...HAL
AVIATION...JP