Area Forecast Discussion Issued by NWS Jackson, KY
000
FXUS63 KJKL 190046
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
846 PM EDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 846 PM EDT SAT MAY 18 2013
ISOLATED TO SCATTERED SHOWERS CONTINUE TO PINWHEEL AROUND THE AREA
BUT COVERAGE IS ON THE DECREASE NOW AS THE SUN SETS. IT ALSO APPEARS
ANY THREAT OF THUNDER IS OVER. SO...PUSHED ALONG AN UPDATE TO REDUCE
RAIN CHANCES INTO THE 20-30 PERCENT RANGE FOR THE REST OF THE NIGHT.
ALSO...BEEFED UP THE WORDING ON THE FOG OVERNIGHT WITH SOME GOOD
BREAKS DEVELOPING IN THE CLOUDS. PATCHY BUT LOCALLY DENSE FOG IS A
GOOD BET LATE TONIGHT INTO EARLY SUNDAY MORNING.
&&
.SHORT TERM...(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 SATURDAY)
ISSUED AT 231 PM EDT SAT MAY 18 2013
THE PERIOD BEGINS WITH UPPER AND SURFACE LOW PRESSURE OVER THE
CENTRAL/NORTHERN PLAINS AND UPPER RIDGING ACROSS THE
CENTRAL/SOUTHERN APPALACHIANS. WITH VERTICALLY STACKED LOW OVER THE
PLAINS THE PATTERN WILL UNDERGO ONLY A VERY SLOW TRANSITION. OUR
REGION WILL BE IN A WARM MOIST SOUTHWEST FLOW THROUGH MUCH OF THE
UPCOMING WEEK...WITH A FEW SHORTWAVES PASSING TO OUR WEST AS THEY
ROTATE AROUND THE MAIN UPPER LOW. WILL BE UNABLE TO RULE OUT
PRECIPITATION CHANCES EVEN IN THE EARLY PART OF THE WEEK...AND WILL
CONTINUE WITH A CHANCE OF CONVECTION DAILY. WILL ALSO CONTINUE TO
FORECAST A RATHER SUPPRESSED DIURNAL TEMPERATURE RANGE WITH FAIRLY
HIGH DEWPOINTS...DAILY CONVECTION CHANCES AND RESIDUAL CLOUD COVER
ACROSS THE AREA. A COLD FRONT WILL ONLY SLOWLY APPROACH EASTERN KY
BY THE SECOND HALF OF THE WORK WEEK...BRINGING A CHANCE FOR MORE
ORGANIZED CONVECTION. THE CENTRAL REGION BLENDED LOAD FOR NDFD
DEPICTS THIS WELL...WITH THE MOST LIKELY SCENARIO PRODUCING THE BEST
RAIN CHANCES FROM WEDNESDAY INTO THURSDAY...BUT WITH HIGH CHANCE
PROBABILITIES LINGERING IN THE SOUTHEAST INTO FRIDAY. WHILE THERE
ARE SOME DIFFERENCES IN HOW THE EVOLVING UPPER AIR PATTERN AND
SURFACE FRONT ARE HANDLED BY THE MODELS...A SLOW PROGRESSION IS
PREFERRED...WITH THE FRONT NOT BEING SOUTH OF THE AREA UNTIL
SATURDAY. DRIER AND COOLER WEATHER WILL THEN BE ON TAP FOR THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 749 PM EDT SAT MAY 18 2013
SCATTERED SHOWERS WILL DIMINISH IN COVERAGE AFTER SUNSET TONIGHT
WITH MAINLY VFR CONDITIONS EXPECTED THROUGH THE EVENING. FOG WILL
THEN BECOME AN INCREASING PROBLEM OVERNIGHT...WITH THE AREAL EXTENT
OF THE FOG DEPENDING ON ULTIMATELY HOW MUCH CLEARING TAKES PLACE.
RECENT TRENDS POINT TO HIGHER CLOUDS SCATTERING OUT SO EXPECT AT
LEAST PATCHY DENSE FOG TO FORM ALONG WITH SOME STRATUS. THE
FOG/STRATUS SHOULD PRODUCE AT LEAST IFR CONDITIONS AT ALL 3 TAF
SITES LATE TONIGHT. WE SHOULD THEN SEE A SIMILAR SITUATION ON SUNDAY
AS WE SAW TODAY WITH SCATTERED SHOWERS DEVELOPING DURING THE LATE
MORNING AND AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...DUSTY
LONG TERM...SBH
AVIATION...ABE