000
FXUS63 KJKL 072145 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
445 PM EST SAT DEC 7 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 257 PM EST SAT DEC 7 2013

PRESENTLY...A COLD FRONT IS STALLED OVER THE TENNESSEE VALLEY WITH
MUCH OF EASTERN KENTUCKY IN THE UPPER 20S TO LOWER 30S ON THE NORTH
SIDE OF THIS BOUNDARY. THERE HAS BEEN SOME EVIDENCE BASED ON OBS THAT
WE ARE SEEING A BIT OF FREEZING FOG AT HIGHER ELEVATIONS. A MID LEVEL
WAVE OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY WILL PUSH NORTHEAST
TONIGHT INTO TOMORROW MORNING...BRINGING THE FRONTAL BOUNDARY BACK TO
THE NORTH AS A WARM FRONT. GOOD DYNAMICS WILL ARRIVE AFTER MIDNIGHT
OVER THE ARE WITH WIDESPREAD PRECIPITATION DEVELOPING. AS IT STANDS
NOW...WE SHOULD SEE A MIX OF PRECIPITATION AT THE ONSET AS THE
MOISTURE RUNS INTO THE COLD AIR ALREADY IN PLACE NORTH OF THE FRONT.
IT LOOKS LIKE DEPENDING ON HOW FAR NORTH/SOUTH YOU ARE WILL BE
DEPENDENT ON THE TYPE OF PRECIPITATION. AREAS IN THE SOUTH WILL
LIKELY START OFF AS EITHER SLEET OR FREEZING RAIN...WITH AREAS
FARTHER NORTH STARTING OFF AS A PERIOD OF SNOW. HOWEVER...IT LOOKS
LIKE ANY SNOW SHOULD QUICKLY CHANGE OVER TO A PERIOD OF SLEET...THEN
EVENTUALLY OVER TO FREEZING RAIN. AS TEMPERATURES WARM FROM THE
SOUTH...WE SHOULD SEE THE FREEZING RAIN THREAT SHIFT NORTHWARD AND
OUT OF EASTERN KENTUCKY DURING THE DAY SUNDAY. DEEPER MOISTURE WILL
EXIT BY SUNDAY AFTERNOON...BUT LOW LEVEL MOISTURE WILL REMAIN
SUPPORTING A PERIOD OF DRIZZLE.

ANOTHER WAVE WILL THEN PUSH ACROSS SOUTHEAST KENTUCKY SUNDAY NIGHT
INTO EARLY MONDAY...PRODUCING THE POTENTIAL FOR MORE RAIN...PERHAPS
HEAVY ACROSS FAR SOUTHEAST KENTUCKY. THIS WILL PRESENT THE AREA WITH
ANOTHER SOAKING RAIN...WHICH WILL CREATE ADDITIONAL FLOODING
CONCERNS. THUS...THE FLOOD WATCH WILL CONTINUE FROM LATE TONIGHT
THROUGH SUNDAY NIGHT. THIS TIME AROUND THE GREATEST THREAT FOR HEAVY
RAIN SHOULD RESIDE ACROSS FAR SOUTHEAST KENTUCKY. MILD WEATHER WILL
ACCOMPANY THE RAIN SUNDAY NIGHT WITH TEMPERATURES CLIMBING INTO THE
40S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 445 PM EST SAT DEC 7 2013

THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY SWEEP A LARGE...FULL
LATITUDE...TROUGH FROM THE PLAINS INTO THE GREAT LAKES AND GRADUALLY
SOUTH THROUGH THE REST OF THE EASTERN U.S. INTO THE DAY THURSDAY.
DEEP LAYER SOUTHWEST FLOW WILL SPREAD OVER EAST KENTUCKY DURING THIS
TIME WITH A DECENT WAVE PASSING THROUGH AT MID LEVELS MONDAY INTO
TUESDAY. FOR THE LATTER PART OF THE WORK WEEK THE PATTERN WILL
BECOME MORE SPLIT AS THE EASTERN TROUGH MOVES OFF TO THE NORTHEAST
AND A SOUTHERN STREAM LOW CROSSES INTO THE SOUTHERN PLAINS. THIS
LATTER TROUGH WILL BE MOVING INTO THE TENNESSEE VALLEY ON FRIDAY...A
BIT SHARPER IN THE ECMWF THAN THE GFS. AS THE CORE OF THIS TROUGH
MOVES THROUGH EAST KENTUCKY ANOTHER ONE WILL DROP INTO THE HIGH
PLAINS FROM THE NORTHWEST AND HELP TO REESTABLISH ONE MAIN FLOW
REGIME FOR THE NATION BY SATURDAY. THE LATEST ECMWF IS MOST
AGGRESSIVE WITH THIS PROCESS AND SWINGS A DEEPENING AND CLOSING OFF
TROUGH THROUGH THE DEEP SOUTH SATURDAY NIGHT. FOR THIS TIME FRAME...
WILL FAVOR A BLEND OF THE GFS AND ECMWF MODEL AND A BROADER BLEND OF
MODELS OVER THE REST OF THE FORECAST WHERE THEY ARE EVEN MORE IN
SYNC WITH EACH OTHER.

SENSIBLE WEATHER FOR THE FIRST PART OF THE EXTENDED WILL REVOLVE THE
WEAKENING ARCTIC FRONT JUST TO THE SOUTHEAST OF THE CWA. A SFC WAVE
OR TWO LIFTING NORTHEAST ALONG THIS BOUNDARY WILL CONTINUE A THREAT
OF LIGHT SNOW OR RAIN ON MONDAY AND INTO TUESDAY MORNING...MAINLY IN
OUR FAR SOUTHEAST. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
KEEPING MOST OF THE WX WELL TO THE NORTH OF KENTUCKY THROUGH MIDWEEK
EVEN AS COLD AIR FILTERS IN TO REINFORCE THE AIR MASS IN PLACE OVER
THE CWA. THERE WILL BE A CHANCE FOR SNOW OR RAIN TO MOVE BACK INTO
THE AREA ON FRIDAY AND LINGERING ON SATURDAY WHEN THAT SOUTHERN
STREAM TROUGH AND TRAILING DEEPER ONE MOVES INTO THE REGION. THE
ECMWF WOULD SUGGEST HIGHER POPS THAN CURRENTLY FORECASTED FOR THIS
PERIOD BUT FOR NOW HAVE TEMPERED ITS FORECAST WITH THAT FROM THE
WEAKER GFS.

THE CR GRID LOAD CAME IN PRETTY GOOD WITH POPS AND SKY COVER EARLY...
BUT NEEDED ADJUSTMENT THROUGH MID WEEK FOR THAT HIGH CROSSING THE
REGION. ALSO UPPED THE POPS AND SKY COVER SOMEWHAT FRIDAY INTO
SATURDAY WITH THAT WAVE REPRESENTED BY THE LATEST ECMWF. ALSO ADDED
IN SOME SMALL RIDGE AND VALLEY TEMPERATURE ADJUSTMENTS TO LOWS FROM
TUESDAY NIGHT THROUGH THURSDAY NIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1227 PM EST SAT DEC 7 2013

IFR/MVFR CIGS WILL REMAIN LOCKED IN ACROSS THE AREA THROUGH THE REST
OF THE DAY. ANOTHER STORM SYSTEM WILL TAKE SHAPE TONIGHT AND PUSH
NORTH INTO THE REGION. THIS WILL SEND ANOTHER SURGE OF MOISTURE
ACROSS THE AREA LATE TONIGHT THROUGH TOMORROW NIGHT. CEILINGS WILL
AGAIN REMAIN IN THE IFR CATEGORY THROUGH MUCH OF THE FORECAST PERIOD.
IN ADDITION...SNOW...FREEZING RAIN...AND SLEET WILL BE POSSIBLE
TONIGHT INTO TOMORROW MORNING BEFORE CHANGING OVER TO RAIN. THE RAIN
COULD BE HEAVY AT TIMES THROUGH MONDAY NIGHT. THIS WILL YIELD SOME
PATCHY FOG AT TIMES AS WELL.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 4 PM EST SUNDAY FOR KYZ044-
050>052-059-060-104-106-107-119.

FLOOD WATCH FROM 1 AM EST SUNDAY THROUGH MONDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.

WINTER WEATHER ADVISORY FROM 3 AM TO 1 PM EST SUNDAY FOR KYZ058-
068-069-108>114-120.

WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SUNDAY FOR KYZ079-
080-083>088-115>118.

&&

$$

SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS