National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KJKL 031838
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
138 PM EST TUE MAR 3 2015

.UPDATE...
ISSUED AT 120 PM EST TUE MAR 3 2015

ISOLATED TO SCATTERED SHOWERS CONTINUED ACROSS A GOOD PORTION OF
KY...MAINLY ACROSS OUR NORTHERN CWA. STILL HAVE MENTION OF CHANCE
POPS...INCLUDING THUNDER...FOR THE REST OF THE AFTERNOON. MAY END
UP TRENDING BACK ON THIS A BIT GIVEN THE ONGOING RADAR TRENDS.
HOWEVER...CONDITIONS ARE RIPE FOR ANY SHOWERS TO BEGIN DEVELOPING
AT ANY TIME...SO MAY END UP KEEPING WITH THE ONGOING CHANCES TO BE
SAFE. UPDATED THE FORECAST /ZFP AND SAF/ TO TAKE OUT ANY MORNING
WORDING FOR ISOLATED SHOWERS.

UPDATE ISSUED AT 1026 AM EST TUE MAR 3 2015

LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG
NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO
EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND
NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER
TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS
SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE
HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES
ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES
THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN
SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A
LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE
LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON
TRACK WITH THE CURRENT CONDITIONS.

UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015

QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR
TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT
WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE
FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE
ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE
ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM EST TUE MAR 3 2015

A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY
THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE
THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS
MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE
THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF
SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN
HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR
NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES
RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED
CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES
DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH
IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL
BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT
THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST
PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS
RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT
TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT
EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY
RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF
THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION
AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT
2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY.
DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY
SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN
TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT
APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST
SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE
KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT
RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE
NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID
50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY
EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR
TODAY.

THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS
MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED
COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO
THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST.
WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE
THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE
EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM
RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE
I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS
FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE
DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE
PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY
AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY
OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS
PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE
ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12
BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE
MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS
SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH
SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE
MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO
SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT
AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS
CURRENTLY PREDICTING.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 557 AM EST TUE MAR 3 2015

APPEARS INCREASINGLY LIKELY THAT WE WILL BE DIVING HEADLONG INTO
A TRANSITION FROM A HEAVY RAIN INTO A SIGNIFICANT WINTER WEATHER
EVENT BY THE BEGINNING OF THE EXTENDED. GFS...ECMWF SOLUTIONS
CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH THIS SCENARIO.
HOWEVER...THE NAM CONTINUES TO TREND FURTHER TO THE NORTHWEST
WITH THE MOST SIGNIFICANT FEATURES IN OUR SENSIBLE WEATHER. WITH
THE NAM OUTSIDE ITS WINDOW OF BEST PERFORMANCE...GENERAL PREFERRED
TO REMAINED CLOSER TO THE OFFICIAL FORECAST AND A CONSENSUS OF THE
GFS AND ECMWF. ENOUGH UNCERTAINTY REMAINS IN THE MODEL SOLUTIONS
TO WARRANT STAYING WITH THE CURRENT SUITE OF WATCH PRODUCTS
THROUGH THE FIRST PORTIONS OF THE EXTENDED.

A VERY TIGHT BAROCLINIC ZONE STRETCHING WSW TO ENE ACROSS THE
OHIO VALLEY WILL GRADUALLY SHIFT SOUTHEAST INTO TENNESSEE VALLEY
THROUGH THURSDAY. WEATHER ALONG THE BAROCLINIC ZONE WILL REMAIN
OF ACTIVE AS SEVERAL WAVES OF LOW PRESSURE TRACK THROUGH THE TN
VALLEY REGION. COLDER ARCTIC AIR FILTERING INTO OUR AREA ON THE
NORTHERN SIDE OF THIS ZONE WILL CHANGE RAIN OVER TO SNOW WEDNESDAY
NIGHT. THERMAL PROFILES SUGGEST THAT THERE WILL BE A PERIOD OF
MIXED PRECIPITATION DURING THE CHANGOVER...GENERALLY SLEET IN THE
NORTH BUT SLEET OR POSSIBLY EVEN SOME FREEZING RAIN IN THE SOUTH.
OVERALL MODEL TRENDS SEEM TO BE SLIGHTLY SLOWER WITH THE
ONSLAUGHT OF COLD ARCTIC AIR INTO OUR FORECAST AREA LATE WEDNESDAY
INTO WEDNESDAY NIGHT. BUT SIGNIFICANT SNOW/SLEET ACCUMULATIONS
STILL APPEAR POSSIBLE...WITH THE HIGHEST AMOUNTS LIKELY NEAR THE
I-64 CORRIDOR AND LESSER AMOUNTS ACROSS OUR SOUTHEAST.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT BEGINNING LATE THURSDAY
NIGHT AND REMAIN OVER THE AREA THROUGH LATE SUNDAY. TEMPS FRIDAY
MORNING WILL LIKELY DIP INTO THE SINGLE DIGITS...WITH A FEW SPOTS
IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...WELL BELOW
NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO
BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK
TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL
GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE
POSSIBLE EARLY NEXT WEEK AS A WEAK FRONTAL BOUNDARY DROPS
SOUTHWARD OUT OF CANADA AND THE GREAT LAKES. BUT WEATHER WITH
THIS FEATURE HAS BEEN TRENDING DRIER WITH TIME. FOR NOW MAINTAINED
A SLIGHT POP SUNDAY NIGHT INTO MONDAY BUT FEEL THIS MAY BE
OVERDONE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EST TUE MAR 3 2015

SCT SHOWERS CONTINUE TO MOVE ACROSS NORTH CENTRAL KY...GENERALLY
PUSHING JUST NORTH OF EASTERN KY...MISSING MOST OF THE TAF SITES.
AS SUCH...TOOK OUT MENTION OF SHRA OR TSRA DIRECTLY IMPACTING THE
TAF SITES THROUGH ABOUT 00Z...THOUGH SOME VCSH OR VCTS ARE STILL
POSSIBLE. AFTER 0Z...EXPECTING PRECIP TO BEGIN INCREASING IN
COVERAGE AND INTENSITY ACROSS KY. WITH INSTABILITY STILL IN
PLACE /DUE TO A STRONG PUSH OF COLDER NORTHERLY AIR INTERACTING
WITH MOIST SRLY FLOW OFF THE GULF OF MEXICO/...COULD SEE SOME
LINGERING POTENTIAL FOR THUNDER THROUGH THE EVENING AS WELL. BY
OVERNIGHT...WE WILL LOSE OUR INSTABILITY...BUT RAIN WILL REALLY
TAKE HOLD. ALL MODELS ARE SHOWING TAF SITES GOING BELOW AIRPORT
MINS THROUGH THE REMAINDER OF THE FORECAST PERIOD...WITH PERIODS
OF VIS AND CIGS LIFR AND BELOW.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY EVENING
FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.

WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-
106>120.

&&

$$

UPDATE...JMW
SHORT TERM...AR
LONG TERM...RAY
AVIATION...JMW