Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KJKL 180800
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
400 AM EDT SAT OCT 18 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM EDT SAT OCT 18 2014

A COLD FRONT PASSED THROUGH ON FRIDAY EVENING. COLD AIR ADVECTION
WILL PERSIST BEHIND THE FRONT TODAY AND TONIGHT. THE CHANGE IN AIR
MASS WILL STEEPEN LOW LEVEL LAPSE RATES ENOUGH THAT LOW CLOUDS WILL
DEVELOP SOUTHWARD OVER THE AREA ON SATURDAY. MEANWHILE...A SHORTWAVE
TROUGH WILL MOVE SOUTHEAST...APPROACHING THE REGION THIS AFTERNOON
AND EVENING. THE GFS AND NAM BOTH SHOW NEARLY SATURATED FORECAST
SOUNDINGS FROM AROUND 925 MB TO 650 MB LATE TODAY AND EARLY THIS
EVENING OVER THE NORTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA...WITH THE TOP OF THE LAYER REACHING -10C FOR ICE SEEDING. THIS
SHOULD RESULT IN SHOWERS. THE QUESTION IS IN THE EXTENT OF COVERAGE.
WHERE MOISTURE DEPTH LOOKS SUPPORTIVE OF PRECIP...HAVE USED 20-30
PERCENT POP. HOWEVER...IF FORECAST SOUNDINGS DO VERIFY...THERE IS
SOME CONCERN THAT THIS MAY BE TOO CONSERVATIVE.

THE SHOWERS WILL DIE OUT TONIGHT AS THE SHORT WAVE PASSES...AND
CLOUDS SHOULD BEGIN TO THIN OUR FROM WEST TO EAST. WITH ENOUGH
CLEARING...FROST COULD BE A CONCERN...AND HAVE INCLUDED PATCHY FROST
IN OUR WESTERN COUNTIES...ESPECIALLY VALLEYS. NOT ENOUGH CONFIDENCE
FOR WIDESPREAD FROST TO CONSIDER AN ADVISORY AT THIS POINT. WILL LET
DAY SHIFT CONTINUE TO MONITOR THIS.

COOL HIGH PRESSURE DRIFTING OVERHEAD FROM THE NW UNDER NW FLOW ALOFT
ON SUNDAY WILL BRING SUNSHINE.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT OCT 18 2014

EASTERN KY WILL FIND ITSELF UNDER A BRIEF AREA OF SURFACE HIGH
PRESSURE AS AN EXITING TROUGH 0Z MONDAY CONTINUES IT/S WAY
EASTWARD. THIS WILL KEEP DRY AND MOSTLY CLEAR SKIES ACROSS THE
REGION FOR THE OVERNIGHT HOURS SUNDAY NIGHT. OPTIMAL RADIATIONAL
COOLING WILL LEAD TO A DECENT RIDGE VALLEY SPLIT IN TEMPERATURES.
WILL KEEP WITH PREVIOUS FORECAST/S MENTION OF POTENTIAL FROST
DEVELOPMENT DURING THIS TIME FRAME IN THE COOLER VALLEY REGIONS. THE
NEXT INCOMING UPPER LEVEL TROUGH WILL BEGIN INFLUENCING THE CWA A
FEW HOURS LATER SUNDAY NIGHT. AN UPPER LEVEL
SHORTWAVE-TURNED-TROUGH...ALONG WITH A SURFACE COLD FRONT WILL
APPROACH THE REGION...INCREASING CLOUD COVER ACROSS EASTERN KY...AND
SHIFTING WINDS TO A MORE SWRLY DIRECTION DURING THE NIGHT. IT WILL
ALSO PULL IN CHANCES OF RAIN SHOWERS TO MUCH OF EASTERN
KY...ESPECIALLY THE NORTH AND FAR EASTERN PORTIONS OF THE CWA. THE
ECMWF AND GFS SOLUTIONS ARE STARTING TO LINE UP A LITTLE BETTER THAN
RUNS FROM 24 HOURS AGO IN REGARDS TO THE EXTENT OF THE
PRECIP...HOWEVER THEY ARE STILL LACKING A BIT IN TIMING AGREEMENT.
THE ECMWF MOVES THE PRECIP INTO THE AREA 3 TO 6 HOURS FASTER THAN
THAT OF THE GFS. GIVEN A CONSENSUS BETWEEN THE TWO...EXPECT BEST
PRECIP CHANCES TO BEGIN ARRIVING BETWEEN 12 AND 18Z MONDAY. CLOUD
COVER WILL HINDER BEST WARMING...WITH HIGHS ONLY EXPECTED TO REACH
THE LOW 60S YET AGAIN.

AS THE UPPER LEVEL SHORTWAVE CONTINUES IT/S EASTWARD TRACK...IT WILL
PRODUCE A DEEPENING TROUGH AND EVENTUALLY A CLOSED LOW AS IT REACHES
OUR CWA. AS THIS OCCURS...MODEL CONSENSUS SHOWS PRECIP CONTINUING
ACROSS PORTIONS OF EASTERN KY THROUGH THE DAY TUESDAY AS
WELL...ESPECIALLY IN THE UPSLOPE REGIONS OF FAR SE KY UNDER THE
INFLUENCE OF NW TO N WINDS. THE UPPER LEVEL LOW WILL THEN BECOME
STAGNANT...KEEPING THE POSSIBILITY FOR UPSLOPE MOISTURE AND SHOWERS
IN THE FAR EAST THROUGH THE DAY WEDNESDAY. FOR THURSDAY INTO
FRIDAY...EXPECT THE LOW TO FINALLY SHIFT FAR ENOUGH EASTWARD THAT
DRY CONDITIONS SHOULD PREVAIL ACROSS THE ENTIRETY OF EASTERN KY.
WHILE THE RAIN AND CLOUD COVER ARE IN PLACE...EXPECT NEAR NORMAL
LOWS...BUT HIGHS WILL NOT BE ABLE TO REACH THEIR MAX
POTENTIAL...ONLY HITTING THE LOW 60S. ONCE THE RAIN MOVES OUT AND A
MUCH COOLER AIR MASS MOVES INTO PLACE...EXPECT TEMPERATURES TO DROP
TO WELL BELOW NORMAL FOR THE REMAINDER OF THE EXTENDED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 308 AM EDT SAT OCT 18 2014

VFR PREVAILED AT THE START OF THE PERIOD IN EASTERN KY...WITH CLEAR
SKIES IN OUR SW COUNTIES AND CEILINGS AROUND 6K FT AGL OVER MUCH OF
THE NE PART OF THE AREA. OVERNIGHT AND DURING THE DAY SATURDAY THE
CEILINGS WILL SHOW AN OVERALL EXPANSION TO THE SOUTH AND LOWER IN
HEIGHT. MOST LOCATIONS ARE EXPECTED TO BE MVFR BY AFTERNOON. AS
COOLING ALOFT OCCURS DURING THE DAY...THE CLOUD DEPTH WILL GROW
GREATER...AND ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO DEVELOP
GENERALLY NORTH AND EAST OF THE CUMBERLAND RIVER BASIN. THE SHOWERS
SHOULD DIE OUT BY THE END OF THE PERIOD. MVFR CEILINGS SHOULD BEGIN
TO BREAK UP ON SATURDAY EVENING OVER THE CUMBERLAND RIVER BASIN AND
THE BLUEGRASS REGION.


&&

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

$$

SHORT TERM...HAL
LONG TERM...JMW
AVIATION...HAL





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.