Area Forecast Discussion Issued by NWS Jackson, KY
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FXUS63 KJKL 172246
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
646 PM EDT FRI MAY 17 2013
.UPDATE...
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ISSUED AT 646 PM EDT FRI MAY 17 2013
UPPER LOW TO OUR WEST WILL CONTINUE TO OPEN TO THE MEAN FLOW AS IT
TRACKS ACROSS THE BLUEGRASS STATE TONIGHT THROUGH SATURDAY NIGHT.
WIDESPREAD LIGHT SHOWERS WILL MOVE NORTH AND AFFECT LOCATIONS ALONG
AND WEST OF I-75 THIS EVENING. TO THE EAST OF I-75...VERY LITTLE
SHOWER ACTIVITY IS CURRENTLY OCCURRING BUT HI-RES SHORT TERM MODELS
POINT TO AN INCREASE IN SHOWERS OVERNIGHT ALONG WITH A FEW
THUNDERSTORMS AND SEE NO REASON TO ARGUE. IN FACT...STORMS OCCURRING
OVER THE TRI-CITIES OF NORTHEAST TENNESSEE MAY HOLD TOGETHER AS THEY
CONTINUE TO TRAVEL NORTHWARD IN AN AREA OF HIGHER SBCAPE EXTENDING
NORTHWARD INTO THE BIG SANDY REGION. EVEN IF THEY DO NOT HOLD
TOGETHER...ADDITIONAL THUNDERSTORM ACTIVITY WILL LIKELY FIRE UP THIS
EVENING AND THEN WANE AFTER SUNDOWN.
WENT AHEAD AND FINE TUNED THE NEAR TERM FORECAST TONIGHT BASED ON
LATEST RADAR TRENDS AND NEAR TERM MODELS. ALSO...TRENDED POPS HIGHER
FOR SATURDAY WITH THE REMNANTS OF THE UPPER LOW OVERHEAD. LOCALIZED
FLOODING WILL BE A CONCERN ON SATURDAY WITH STORM MOTIONS PROGGED TO
BE LESS THAN 5 KNOTS AND PWATS APPROACHING 1.5 INCHES.-- End Changed Discussion --
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.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 220 PM EDT FRI MAY 17 2013
A CUTOFF AREA OF LOW PRESSURE CONTINUES TO SPIN OVER FAR WRN KY WITH
BANDS OF SHOWERS AND ISOLATED THUNDERSTORMS MOVING NORTH AND
NORTHEAST FROM THE CENTER OF CIRCULATION. THIS WAVE IS SCHEDULED TO
MOVE EAST TO MIDDLE KY BY LATE SAT NIGHT. THIS WILL KEEP ERN KY UNDER
THE THREAT OF NEARLY CONTINUOUS BANDS OF RAIN. TEMPS WILL REMAIN ON
THE COOL SIDE FOR MIDDLE MAY WITH HIGHS ON SAT ONLY ABLE TO SQUEEZE
OUT MIDDLE 70S WITH THE SOUTHERLY FLOW ADVECTING WARM AIR INTO THE
REGION TO COUNTER THE CHILLING EFFECT OF THE RAIN. FCST DWPTS IN THE
LOWER 60S INDICATE ENOUGH MOISTURE FOR THUNDER...HOWEVER THE SKINNY
CAPE AND CLOUD COVER WILL PRECLUDE WIDESPREAD THUNDERSTORMS AND
LIKELY NOTHING SEVERE. THE OVERCAST SKY WILL ALSO HELP TO HOLD
OVERNIGHT LOWS IN THE LOWER 60S. IN BETWEEN PERIODS OF RAIN THE
OVERNIGHT TEMPS WILL COOL ENUF FOR PATCHY FOG TO FORM. THE FOG COULD
BECOME RATHER DENSE WITH OCCASIONAL VISIBILITIES LESS THAN A QUARTER
OF A MILE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 300 PM EDT FRI MAY 17 2013
THE LONG TERM MODELS WERE NOT IN THE BEST AGREEMENT FOR THE EXTENDED
PERIOD. THE GFS WAS A BIT MORE ACTIVE THAN THE ECWMF OVERALL...WITH
TIMING DIFFERENCES ALSO SHOWING UP BETWEEN THE TWO MODELS THROUGH THE
END OF THE WEEK. THAT BEING SAID...USED A BLEND OF THE TWO TO
FORMULATE THE FORECAST THIS TIME AROUND. OVERALL...THE MEXMOS POPS
DID LOOK PRETTY GOOD FOR THE PERIODS THAT SHOWERS AND STORMS WERE
INCLUDED IN THE FORECAST. WENT PERHAPS SLIGHTLY LOWER THAN THE
HIGHEST POPS IN THE MOS DATA TO ACCOUNT FOR THE UNCERTAINTY INVOLVED.
THE MOST ACTIVE PERIOD OF THE FORECAST WOULD APPEAR TO BE SUNDAY
AFTERNOON AND EARLY EVENING...AND THE WEDNESDAY THROUGH FRIDAY TIME
FRAME. IT APPEARS THAT A FRONTAL BOUNDARY WILL BE THE CULPRIT OF ANY
PRECIPITATION THAT OCCURS FROM MIDWEEK ONWARD...ONCE THE BOUNDARY IS
ABLE TO PUSH OUT OF THE OHIO VALLEY AND ACROSS CENTRAL AND EASTERN
KENTUCKY. BEFORE THAT...A STUBBORN RIDGE OF HIGH PRESSURE COULD KEEP
THE FRONT AT BAY TO THE NORTH...WITH THE FRONT OCCASIONALLY
MEANDERING FAR ENOUGH SOUTH TUESDAY AND TUESDAY NIGHT TO BRING
SCATTERED SHOWERS AND STORMS TO THE AREA. TEMPERATURES SHOULD RUN
CLOSE TO THE MOS NUMBERS ACROSS THE BOARD...BUT DECIDED TO GO
SLIGHTLY COOLER THAN THE MEXMOS DATA TO ACCOUNT FOR THE CLOUDS AND
PRECIPITATION EXPECTED THROUGHOUT THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 118 PM EDT FRI MAY 17 2013
AN UPPER LOW OVER MISSOURI WILL PINWHEEL CLOUDS AND SHOWERS ACROSS
THE AREA TODAY AND THIS EVENING. THE AREA SHOULD STAY MOSTLY VFR
DURING THE DAY. SOME OF THE HEAVIER SHOWERS MAY DROP THE CIG AND VSBY
TO MVFR. THE WEATHER SHOULD REMAIN UNSTABLE FOR A FEW DAYS. EXPECT
THE FOG TO BE MORE WIDE SPREAD IN THE MORNING AND THE RAIN SHOULD
ENTER THE FORECAST SOONER.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...DUSTY
LONG TERM...AR
AVIATION...DUSTY