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000
FXUS63 KPAH 210736
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
236 AM CDT TUE MAY 21 2013

.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 215 AM CDT TUE MAY 21 2013

NEAREST TERM IS DEALING WITH REMAINING CONVECTION/TOR WATCH BOX.
IN GENERAL...THE TREND IS DIMINISHING IN STRENGTH/INTENSITY AS THE
LINE SINKS SOUTHWARD AND EASTWARD. A FEW HEALTHY CELLS MAY
CONTINUE TO PULSE...HOWEVER...AND WITH A COUPLE OF OUTFLOW
BOUNDARIES WORKING OUT OF THE NORTHERN AND SOUTHERN PORTIONS OF
THE CONVECTIVE LINE...WE`LL ONLY DROP WATCH BOX COUNTIES BEHIND
THE LINE.

THE MODELS SHOW THE CONVECTION MOVING EAST...WEAKENING...AND THEN
REFIRING THIS PM/EVENING AS THE UPPER LEVEL JET ENTERS THE
PICTURE. BEST LIFT/INSTABILITY WILL BE TO OUR SOUTH...BUT A SLGT
RISK OF SVR WILL CONTINUE. WOULD NOT BE SURPRISED TO SEE A PTN OF
THE CWA/ESP SEMO/SWKY/SWIL...INCLUDED IN A LATE DAY-EARLY EVENING
WATCH BOX.

ASSOCIATED SURFACE WAVE OPENS UP AND LIFTS ACROSS MO/IL/IN
TONIGHT. THIS WILL DRIVE THE FRONT AND ASSOCIATED CONVECTION THRU
THE AREA. INSTABILITY LESSENS WITH TIME/OVERNIGHT BUT ACTIVE
CONVECTION EARLY IN THE PERIOD MAY EXTEND THRU THE
NIGHT...SOMETHING TO WATCH AND A HIGH POP/CATEGORICAL MENTION IS
WARRANTED EITHER WAY.

THE UPPER TROF/BEST HEIGHT FALLS OCCUR WEDNESDAY AND DRIVE THE
SYSTEM THRU/TO THE EAST OF US THRU WEDNESDAY NIGHT. POPS MAY EVEN
LINGER THRU THURSAY AS 2NDARY UPPER TROF PASSAGE ALLOWS SOME
DIURNAL INSTABILITY SHOWERS/STORMS TO DEVELOP...PARTICULARLY NRN/ERN
PTNS FA. THE SYSTEM DEPARTS TO THE EAST BY THU NIGHT...WHEN
PLEASANTLY COOLER/DRIER AIR STARTS TO OVERTAKE THE COLUMN. 80S AND
60S COOL TO 70S AND 50S THEREAFTER.

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 236 AM CDT TUE MAY 21 2013

DRY AND TRANQUIL WEATHER IS EXPECTED LATE IN THE WEEK WITH HIGH
PRESSURE RIDGING AT THE SURFACE AND ALOFT. TEMPERATURES ARE LIKELY
TO REMAIN IN THE 70S ON FRIDAY...AND REACH JUST SHY OF THE SEASONAL
80 DEGREE MARK ON SATURDAY. A WARMING TREND WILL TAKE PLACE OVER THE
WEEKEND INTO EARLY NEXT WEEK AS LOW LEVEL FLOW BECOMES SOUTHERLY ON
THE BACK SIDE OF DEPARTING HIGH PRESSURE.

MODELS CONTINUE TO DIFFER IN THEIR HANDLING OF A BAROCLINIC ZONE
FORECAST TO DEVELOP JUST NORTH OF THE REGION EARLY NEXT WEEK...AND
THUS WITH REGARD TO PRECIPITATION CHANCES AS WELL. BOTH THE GEM AND
ESPECIALLY THE GFS HAVE BEEN FAIRLY CONSISTENT IN KEEPING THE
BOUNDARY AND CONVECTIVE POTENTIAL MAINLY NORTH OF THE REGION AS A
MID LEVEL RIDGE REMAINS IN PLACE LOCALLY. ON THE OTHER HAND...THE
ECMWF SEEMS TO SUGGEST THE BOUNDARY AND ASSOCIATED PRECIPITATION
WILL MEANDER SOUTH INTO THE REGION BY MONDAY. GIVEN THE RATHER POOR
RUN TO RUN CONSISTENCY OF THE ECMWF AND THE PRESENCE OF THE MID
LEVEL RIDGE...PREFER TO STEER THE FORECAST IN THE DIRECTION OF THE
DRIER GFS AT THIS TIME.

WILL ALSO KEEP TEMPERATURES ABOVE THE INITIALIZED GUIDANCE BLEND
LATE IN THE PERIOD. THIS YIELDS HIGHS IN THE LOWER TO MID 80S BOTH
SUNDAY AND MONDAY...WITH LOWS IN THE LOWER TO MID 60S.

&&

.AVIATION...
ISSUED AT 215 AM CDT TUE MAY 21 2013

ACTIVE ONGOING CONVECTION AT THIS WRITING. GUST FRONTS PRODUCING
WINDS/GUSTS TO 35 KTS PRECEDE MAIN LINE OF CONVECTION ROUGHLY 30-60
MINUTES WHERE STORM GUSTS MAY LIKEWISE REACH 35 KTS OR BETTER.
EXPECT MOST INTENSE ACTIVITY NEXT 2-3 HOURS TO THEN DETERIORATE TO
MORE MODERATE SHOWER ACTIVITY WITH MVFR CONDITIONS IMPROVING TO
VFR BY MID MORNING. PM REDEVELOPMENT WILL HAVE HIGHEST POPS WEST
TO LOWEST EAST...WITH RETURN TO MVFR CONDTIONS BY EVENING
EXPECTED AS ANOTHER ROUND HITS TERMINALS/FLIGHT PATHS. IN BOTH
INSTANCES A STRONG STORM MAY PRODUCE IFR CIGS/VSBYS ALBEIT SHORT-
LIVED.


&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$