FXUS63 KJKL 270528
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1228 AM EST FRI NOV 27 2009

.SHORT TERM.../THE REST OF TONIGHT/

CONSIDERABLE RAIN AND SNOW SHOWER ACTIVITY ACROSS THE CWA THIS
EVENING. SNOW HAS ALREADY MIX DOWN INTO THE VALLEYS THIS EVENING...
WITH EVEN SME REPORTING SOME LIGHT SNOW...UNKN PRECIP. RADAR RETURNS
ARE QUITE HIGH IN OUR MORE NORTHEASTERN ZONES...CLIMBING ABOVE 40 DB
AT TIMES. UPDATE THIS EVENING WAS TO INCREASE POPS ACROSS THE NORTH
AND EAST WITH MORE ROBUST PRECIPITATION OCCURRING IN UPSLOPE FLOW. IN
ADDITION...HOURLY TRENDS IN TEMPS WOULD SUGGEST OVERNIGHT LOWS A FEW
DEGREE BELOW THOSE ORIGINALLY ADVERTISED. IN GENERAL SNOWFALL AMOUNTS
LOOKS GOOD...WITH UP TO AN INCH POSSIBLE ABOVE 2000 FEET. HOWEVER...
THE GROUND IS STILL QUITE WARM AND WOULD EXPECT THE BEST OPPORTUNITY
FOR ANY SIGNIFICANT ACCUMULATIONS TO BE LIMITED TO THE VERY HIGHEST
ELEVATIONS ALONG THE KY...VA STATE LINE. FOR EXAMPLE...BLACK MOUNTAIN
MIGHT PICK UP 2 INCHES...MAYBE THREE AND THEN MAINLY ON GRASSY OR
EXPOSED SURFACES.

THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...

/TONIGHT THROUGH SATURDAY NIGHT/

A TROUGH WILL PASS EAST OVER THE REGION TONIGHT. THE LOWER/MID LEVEL
PORTION OF THE TROUGH WILL BE PRECEDED BY WARM AIR ADVECTION IN THE
850-700 MB LAYER...WITH THE ASSOCIATED ISENTROPIC LIFT BRINGING
CLOUDS AND A POTENTIAL FOR PRECIP. PRECIP TYPE WILL BE A FUNCTION OF
TEMPS IN THE LOWEST LEVELS...WITH AIR ALOFT COLD ENOUGH TO SUPPORT
FORMATION AS SNOW. WITH THE WARMEST AIR AT THE SURFACE AND THE FREEZING
LEVEL EXPECTED AROUND 2K FEET IN THE PRECIP AREA...WILL EXPECT SNOW
TO MIX IN AT SURFACE TEMPS WELL ABOVE FREEZING...PROBABLY AROUND 36.
ABOVE 2K FEET WHERE SURFACE TEMPS WILL DIP BELOW FREEZING...SOME
LIGHT ACCUMULATION OF UP TO AN INCH MAY OCCUR.

DEEP MOISTURE WILL BE MOVING OUT BY 12Z...WITH DRY AIR AT LEVELS
COLDER THAN -10C BY THAT TIME...SO WILL NOT INCLUDE PRECIP ON
FRIDAY. WITH RIDGING AT THE SURFACE AND ALOFT BUILDING IN FROM THE
WEST ON FRIDAY...SKIES WILL BECOME MOSTLY SUNNY DURING THE DAY.
CLEAR OR MOSTLY CLEAR SKIES THEN LAST THROUGH SATURDAY NIGHT. AS THE
SURFACE RIDGE SLIPS TO OUR EAST ON FRIDAY NIGHT...WARM AIR ADVECTION
WILL RETURN THROUGH THE REMAINDER OF THE PERIOD. THIS WILL LEAD TO
RIDGE/VALLEY LOW TEMP DIFFERENCES BOTH FRIDAY NIGHT AND SATURDAY
NIGHT. 

.LONG TERM.../SUNDAY THROUGH THURSDAY/

SPLIT STEAM FLOW BETWEEN POLAR AND SUBTROPICAL JET WILL MAKE THE 
EVOLUTION OF THE EXTENDED UNPREDICTABLE...ALTHOUGH IT CAN BE SAID 
WITH CONFIDENCE THAT THE PERIOD WILL BE QUITE ACTIVE. CONFIDENCE 
REMAINS FAIRLY HIGH IN THE FIRST OF WEATHER MAKING SYSTEM IMPACTING 
THE AREA MAINLY ON MONDAY. HAVE CONTINUED LIKELY POPS FOR THE MONDAY 
AFTERNOON TIME PERIOD...WITH GRADUALLY INCREASING/DECREASING POPS ON 
EITHER SIDE. THIS EVENT...IN THE FORM OF ALL RAIN...WILL BE THANKS 
TO A STRONG COLD FRONT PUSHING THROUGH THE AREA ON MONDAY NIGHT. MID 
LEVEL SUPPORT WILL EXIST IN THE FORM OF POSITIVE TILT TROUGH AND THE 
UPPER LEVELS SUPPORTED BY A 140 KNOT H3 JET. WILL LINGER POPS IN A 
BIT LONGER ON TUESDAY TO ACCOUNT FOR BRIEF PERIOD OF UPSLOPE FLOW...
HOWEVER MOISTURE SHOULD BE FAIRLY SHALLOW AND FLOW BECOMES 
UNFAVORABLE BY LATE TUESDAY MORNING.

BRIEF RIDGING LOOKS TO BUILD INTO THE AREA TUESDAY AND TUESDAY NIGHT 
BEFORE THE APPROACH OF A MID LEVEL WAVE AROUND THE GULF OF MEXICO 
DRIVEN BY AN ACTIVE SUBTROPICAL JET. AT THIS POINT...MODELS ARE 
DEVELOPING A SURFACE LOW THAT TRACKS SOUTH OF THE CWA WITH PLENTY OF 
MOISTURE TO WORK WITH. LOW LEVELS LOOK TO BE TOO WARM FOR MUCH IN 
THE WAY OF FROZEN PRECIPITATION AT THIS POINT...HOWEVER WILL HAVE TO 
KEEP AN EYE ON HOW THIS SYSTEM EVOLVES. HAVE GRADUALLY INCREASING 
POPS FROM SOUTH TO NORTH ON WEDNESDAY AND WEDNESDAY NIGHT...HOWEVER 
WILL TAPER POPS IN THE EASTERN CWA AS STRONG SOUTHEASTERLY FLOW IN 
THE LOW LEVELS OVER THE TERRAIN WILL CREATE DOWNSLOPING/DRYING AND 
WILL TAKE LONGER TO SATURATE COLUMN. WILL GO WITH CHANCE POPS FOR 
NOW UNTIL DETAILS BECOME A BIT MORE AGREEABLE AMONGST MODELS.

KEPT WITH THE TREND WELL BELOW GUIDANCE ON SUNDAY AFTERNOON AS CLOUD 
COVER DAMPENS MIXING HEIGHTS AND STAYED WELL BELOW GUIDANCE. SUNDAY 
NIGHT AND MONDAY SHOULD BE A LOW DIURNAL RANGE AS RAIN KEEPS LOW 
TEMPS UP AT NIGHT AND CLOUDY SKIES KEEP HIGH TEMPS DOWN. SKIES BEGIN 
TO CLEAR ON MONDAY NIGHT AND TUESDAY AND PARTLY CLOUDY SKIES SHOULD 
ALLOW FOR SOME TEMPERATURE RECOVERY DESPITE COLD FRONTAL PASSAGE. 
HIGHS IN THE MID TO UPPER 40S LOOK REASONABLE. TUESDAY NIGHT COULD 
FAVOR A SMALL RIDGE/VALLEY SPLIT UNDER PARTLY CLOUDY SKIES AND 
RETURN FLOW AT THE RIDGETOP LEVEL. SECOND SYSTEM APPROACHES FROM THE 
SOUTH WITH SMALL DIURNAL RANGES ONCE AGAIN ON WEDNESDAY...WEDNESDAY 
NIGHT...AND THURSDAY.
&&

.AVIATION.../06Z TO 06Z/...UPDATED

SCATTERED RAIN/SNOW SHOWERS WILL DIMINISH OVER THE NEXT FEW HOURS AS
RESPONSIBLE UPPER TROUGH MOVES PAST AND MOISTURE DEPTH SHRINKS. LOW
CLOUDS WILL LINGER DEEP INTO THE MORNING HOURS HOWEVER. IFR
CONDITIONS WILL LIKELY CONTINUE FOR JKL AND OTHER RIDGETOP LOCATIONS
UNTIL CIGS BEGIN TO RISE SHORTLY AFTER SUNRISE. OTHERWISE... EXPECT
LOW MVFR CIGS TO REMAIN IN PLACE BEFORE SLOWLY RISING AND BREAKING
UP FROM SOUTHWEST TO NORTHEAST LATE MORNING/EARLY AFTERNOON ON
FRIDAY. WEST WINDS WILL ALSO REMAIN A BIT GUSTY THROUGH THE DAYTIME
FRIDAY BUT WILL RELAX WITH THE SETTING SUN FRIDAY EVENING.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...HAL/RAY
LONG TERM....SCHOETTMER
AVIATION...ABE