National Weather Service National Headquarters

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

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 181824
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
224 PM EDT SAT MAY 18 2013

.SHORT TERM...
-- Changed Discussion --
(THIS EVENING THROUGH MONDAY)
ISSUED AT 223 PM EDT SAT MAY 18 2013

THE PRIMARY WEATHER MAKER IN THE SHORT TERM IS A MID LEVEL LOW
PRESSURE AREA DRIFTING ACROSS THE COMMONWEALTH UNDER A GENERAL RIDGE.
THE GFS SHOWS THIS AS MORE OF AN OPEN WAVE WHILE THE ECMWF KEEPS THIS
SYSTEM CLOSED LONGER AND ONLY OPENS THE WAVE AS IT MOVES INTO WRN VA
SUNDAY AFTERNOON. THE NEXT SYSTEM IS A TROF THAT DROPS OUT OF THE NRN
ROCKIES LATE SUNDAY AND ONLY MAKES IT AS FAR EAST AS NEB BY MONDAY
MORNING. AT THE SFC...SEVERAL WAVES WILL ROTATE FROM SOUTH TO NORTH
ACROSS THE AREA WITH PERIODS OF RAIN ASSOCIATED WITH EACH WAVE.
DEPENDING ON THE TIMING OF INDIVIDUAL WAVES...THERE COULD BE SOME
THUNDER BUT THE CLOUD COVER AND DEEP LAYER OF MOISTURE WILL PRECLUDE
MOST THOUGHTS OF SEVERE WEATHER. PCPN WILL BE PERIODIC UNTIL MONDAY
MORNING WHEN WE APPEAR TO BE BETWEEN THE DEPARTING OPEN WAVE AND THE
NEXT DISTURBANCE IN THE CNTRL PLAINS. SOUTHERLY FLOW WILL HELP PUSH
HIGH TEMPS A BIT WARMER EACH DAY WHILE THE CLOUD COVER WILL INHIBIT
OVERNIGHT LOWS FROM DROPPING BELOW THE LOWER 60S. SUNDAY HIGHS WILL
BE WITHIN A DEG OR SO OF THE 80 DEG MARK WHILE HIGHS ON MONDAY WILL
EASILY CLIMB INTO THE MID 80S.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 425 AM EDT SAT MAY 18 2013

THE PERIOD IS EXPECTED TO BEGIN WITH A WEAKENING UPPER LEVEL
LOW/SHORTWAVE TROUGH DEPARTING TO THE EAST OF THE REGION AND
SHORTWAVE UPPER LEVEL RIDGING WORKING INTO THE LOWER OH VALLEY
REGION. FURTHER WEST...A TROUGH AND CLOSED LOW IS EXPECTED FROM THE
ROCKIES INTO THE PLAINS STATES. THE AXIS OF THE RIDGING IS EXPECTED
TO WORK EAST ACROSS THE REGION ON MON INTO MON EVENING...FOLLOWED BY
SW FLOW ALOFT AHEAD OF THE TROUGH AND CLOSED LOW. A FEW SHORTWAVES
IN THIS SOUTHWEST FLOW ROTATING AROUND THE CLOSED WILL PASS
GENERALLY TO THE WEST OF SOUTH CENTRAL AND EASTERN KY THROUGH
MIDWEEK. EVENTUALLY THIS SYSTEM WILL BEGIN TO OPEN UP A BIT AND
WEAKEN BUT THERE IS CONSIDERABLE UNCERTAINTY AS TO WHETHER OR NOT IS
BECOMES ABSORBED BY AN UPPER LEVEL LOW DROPPING SOUTH INTO ONTARIO
AND QUEBEC LATE IN THE PERIOD PER LATEST ECMWF RUN OR MEANDERS
ACROSS THE OH VALLEY TOWARD THE APPALACHIANS OR MID ATLANTIC STATES
ABOUT A WEEK FROM NOW. AT THE SFC...THE COLD FRONT ASSOCIATED WITH
THE SHORTWAVE TROUGH SHOULD WORK INTO THE REGION LATE IN THE
PERIOD...BUT POSSIBLY NOT EXIT THE CWA BEFORE THE END OF THE PERIOD.

AT THIS POINT...THE FORECAST LEANS A BIT TOWARD THE 00Z ECMWF AND 00Z
GFS FOR TRENDS LATE IN THE PERIOD...BUT THE MODEL CONSENSUS GRID LOAD
WAS GENERALLY FOLLOWED. POPS FROM LATE MON INTO MON NIGHT WERE
LOWERED 10 OR SO PERCENT ON AVERAGE FROM THE GRID LOAD THE RIDGE
SHOULD BRING SOME CAPPING. HOWEVER...EVEN LATE IN THE PERIOD...IF
THE ECMWF VERIFIES THE SFC BOUNDARY WILL BE IN THE VICINITY...AND
THUS CHANCES FOR PRECIP REALLY CANNOT BE RULED OUT COMPLETELY IN ANY
PERIOD. AT THIS POINT THE LOWEST CHANCES APPEAR TO BE FROM LATE
AFTERNOON MONDAY INTO MONDAY NIGHT...AND PERHAPS INTO TUESDAY.

DIURNAL RANGES WILL BE A BIT SUPPRESSED BY ANTICIPATED PERIODIC
CLOUD CLOUD COVER...RELATIVELY WARM AND MOIST AIR MASS IN THE WARM
SECTOR...AND SCATTERED CONVECTION FROM TIME TO TIME. HIGHS WILL
GENERALLY BE IN THE LOW TO MID 80S THROUGH MIDWEEK WITH LOWS IN THE
LOW TO MID 60S. AS THE BOUNDARY AND UPPER SYSTEM WORK ACROSS THE
AREA LATER IN THE PERIOD...HIGHS SHOULD GENERALLY BE IN THE 70S WITH
LOWS IN THE 60S.
-- End Changed Discussion --

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 140 PM EDT SAT MAY 18 2013

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL PASS ACROSS EASTERN KENTUCKY
THROUGH TODAY...PROVIDING A FOCUS FOR BOUTS OF SHOWERS AND SCATTERED
THUNDERSTORMS. THE COVERAGE WILL BE GREATEST DURING THE AFTERNOON AND
EARLY EVENING HOURS. TEMPORARY IFR OR WORSE CONDITIONS WILL BE
POSSIBLE WITHIN ANY THUNDERSTORMS. THE ADDED MOISTURE WILL PRODUCE
SOME PATCHY IFR FOG IN THE MORNING.


&&

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

$$

SHORT TERM...DUSTY
LONG TERM...JP
AVIATION...DUSTY