000
FXUS63 KJKL 131148
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
748 AM EDT THU MAR 13 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EDT THU MAR 13 2014

CURRENT RADAR TRENDS ARE PUSHING THE SNOW OUT SLIGHTLY FASTER THAN
WAS ORIGINALLY ANTICIPATED...WITH A FEW RADAR RETURNS REMAINING
ACROSS THE SW CWA AND THE FAR NE CWA. MOST OF THESE RETURNS ARE NOT
SHOWING UP ON THE GROUND OBSERVATION SITES...BUT SOME FLURRIES TO
ISOLATED LIGHT SNOW SHOWERS CANNOT BE RULED OUT OVER THE NEXT FEW
HOURS. OTHERWISE...COLD AND DRIER ARCTIC AIR IS CONTINUING TO DIVE
INTO THE REGION. WINDS WILL REMAIN NW DURING MOST OF THE DAY
TODAY...CONTINUING TO DIE DOWN IN MAGNITUDE AS PRESSURE GRADIENTS
CEASE AND HIGH PRESSURE TAKES CONTROL OVERHEAD.

DESPITE FAIR AMOUNT OF MOISTURE THAT MOVED ACROSS THE REGION IN THE
LAST 24 HOURS...SOUNDINGS ARE STILL SUPPORTING THAT INCOMING AIRMASS
WILL BE QUITE DRY AT ALL LEVELS. ADD IN THE MODERATE NW WINDS
PULLING IN THIS DRY AIR...AND ABUNDANT SUNSHINE...THIS WILL BE A DAY
TO WATCH FOR LOW RH VALUES AND FIRE POTENTIAL. NOT QUITE MEETING ALL
THE CRITERIA TO PUT A WATCH OUT...AND LINGERING GROUND MOISTURE WILL
HELP A LITTLE...BUT DEFINITELY SOMETHING TO KEEP AN EYE ON. EVEN
WITH TEMPS ONLY REBOUNDING INTO THE UPPER 30S AND LOW 40S ACROSS THE
REGION...STILL EXPECTING RH VALUES TO BOTTOM OUT IN THE MID 20S IN
MANY LOCATIONS BY THE AFTERNOON.

CONDITIONS WILL CHANGE AGAIN AS WE HEAD INTO THURSDAY NIGHT/FRIDAY.
AS OF 6Z FRIDAY...MODELS ARE IN GOOD AGREEMENT OF YET ANOTHER
SHORTWAVE DEVELOPING ACROSS THE NORTHERN PLAINS/SOUTH CENTRAL
CANADA...AND PUSHING SE THROUGH THE DAY FRIDAY. LUCKILY...THIS
SYSTEM WILL BE MUCH WEAKER AND THEREFORE THE SOUTHERN EXTENT OF THIS
SHORTWAVE WILL NOT COMPARE TO THE PREVIOUS...SO THERE WILL BE NO
WORRY OF ANOTHER ARCTIC BLAST. IN FACT...IT WILL BE QUITE OPPOSITE.
THE TRACK OF THIS SYSTEM WILL PUT MUCH OF THE OHIO RIVER VALLEY INTO
A SPLIT FLOW PATTERN ALOFT...WITH WEAK TROUGHING TO THE NORTH AND
GENERALLY ZONAL FLOW TO THE SOUTH BY DURING THE DAY FRIDAY. THIS
SHORTWAVE WILL ALSO PRODUCE A LOW PRESSURE SYSTEM WHICH WILL PASS
INTO THE UPPER GREAT LAKES THURSDAY NIGHT. AS THE LOW PRESSURE
SYSTEM MOVES EASTWARD...A WARM FRONT WILL EXTEND SOUTHWARD AND
TRAVERSE MUCH OF KY THROUGH THE DAY SATURDAY. WITH SUCH A DRY
AIRMASS ALREADY IN PLACE...AND LITTLE MOISTURE EXPECTED ON THE
SOUTHERN EXTENT OF THE SURFACE LOW PRESSURE SYSTEM...THE ONLY THING
THAT CAN BE EXPECTED WITH THE INCOMING WARM FRONT THROUGH 0Z
SATURDAY IS A CHANGE IN WIND DIRECTION TO THE SOUTH...INCREASING IN
MAGNITUDE ONCE MORE...AND FAST REBOUND IN TEMPERATURES. HIGHS FRIDAY
WILL JUMP BACK INTO THE UPPER 50S/AROUND 60 ACROSS THE REGION. THAT
IS A 20 DEGREE REBOUND FROM 24 HOURS BEFORE.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 357 AM EDT THU MAR 13 2014

THE MODELS START OUT IN PRETTY GOOD AGREEMENT WITH A FAIRLY ZONAL
FLOW ACROSS THE US. THE PROMINENT FEATURES ARE AN UPPER TROUGH OVER
NEW MEXICO ASSOCIATED WITH THE SOUTHERN STREAM AND A BROAD TROUGH
OVER THE GREAT LAKES ASSOCIATED WITH THE NORTHERN STREAM. THE
INITIAL FORECAST DIFFICULTLY IS TO BE ABLE TO DETERMINE HOW FAR
SOUTH THE NORTHERN STREAM WILL BE ABLE TO PUSH COLD FRONTS AND THEN
THE TIMING OF THE NEXT SOUTHERN STREAM SYSTEM WHICH WELL BE TRACKING
A SURFACE LOW SOUTH OF THE AREA ON SUNDAY. BY SUNDAY MORNING...THE
ECMWF HAS THE UPPER LOW OVER THE TEXAS PANHANDLE WHILE THE GFS JUST
DEEPENS THE LOW AND SINKS IT TO THE SOUTH OVER SOUTHERN NEW MEXICO.
JUST BASED ON VERIFICATION...TRENDED THE FORECAST TOWARD THE ECMWF
SOLUTION HOWEVER CONFIDENCE IS BELOW NORMAL DUE TO THE MODEL
DIFFERENCES. THE INTERACTION BETWEEN THE TWO SYSTEMS SHOULD RESULT
IN SOME RAIN SPREADING ACROSS THE AREA ON SATURDAY WITH THE
PRECIPITATION CONTINUING THROUGH SUNDAY AND THEN CHANGING OVER TO
SNOW AS THE COLD AIR MOVES INTO THE AREA ON SUNDAY NIGHT. THIS COULD
LEAD TO A TRACE OF SNOW IN THE SOUTH AND TO A HALF AN INCH OF SNOW
NORTH OF THE MOUNTAIN PARKWAY. THE ECMWF IS SLOWER WITH THE SYSTEM
THAN THE GFS. THE UPPER TROUGH ASSOCIATED THIS SYSTEM MOVES TO THE
EAST OF THE AREA BY MONDAY MORNING AS HIGH PRESSURE MOVES INTO THE
AREA.

FOR THE TEMPERATURES...NUDGED THE MODEL BLEND TOWARD THE
ECMWF...HOWEVER AS THE TIMING OF THESE SYSTEMS CHANGES...THERE COULD
BE SOME BIG SWINGS IN THE TEMPERATURE FORECASTS. WITH CONFIDENCE SO
LOW...DO NOT WANT TO GO TO EXTREME ON UNCERTAIN TIMING.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 744 AM EDT THU MAR 13 2014

VFR EXPECTED FOR THE ENTIRE PERIOD. WINDS WILL BECOMING MORE WESTERLY
THIS EVENING AND THEY SOUTHWESTERLY AND GUST ON FRIDAY MORNING.

&&

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

$$

SHORT TERM...JMW
LONG TERM...JJ
AVIATION...JJ