000
FXUS63 KPAH 212013
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
313 PM CDT TUE MAY 21 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 245 PM CDT TUE MAY 21 2013

A VERY COMPLEX SITUATION DURING THE NEXT 24-36 HOURS.

SEVERAL GROUPS OF THUNDERSTORMS GOING ON TO OUR SOUTH WHILE ISOLATED
STORMS HAVE DEVELOPED OVER SOUTHEAST MISSOURI AND FAR WESTERN
KENTUCKY.

THE MAIN SHORT WAVE AND MAIN BAND OF THUNDERSTORMS...CURRENTLY
OVER EASTERN OKLAHOMA...WILL ARRIVE IN THE WESTERN SECTIONS THIS
EVENING AND SHOULD BE NEAR THE MISSISSIPPI RIVER BY MIDNIGHT. HIGH
RESOLUTION MODELS PRODUCE DIFFERENT SCENARIOS...ONE OF WHICH IS TO
TAKE THE MAIN AREA OF THUNDERSTORMS SOUTH. HOWEVER...STILL LOOKS
LIKE A GOOD CHANCE OF STORMS ACROSS AT LEAST THE SOUTHERN SECTIONS
TONIGHT. PRECIPITABLE WATER VALUES OVER 1.5 OVER MOST OF THE
SOUTHERN SECTIONS CURRENTLY. AS WAVES OF STORMS MOVE THROUGH THERE
ARE HINTS OF SOME REGENERATION OVER WESTERN KENTUCKY TONIGHT. SO
HEAVY RAINFALL HAS BEEN ADDED TO THE GRIDS.

CHANCES OF SEVERE WEATHER ARE NOT CLEAR. ISOLATED SEVERE LATE
THIS AFTERNOON AND EARLY EVENING. STORMS MAY RAMP UP AGAIN AROUND
MIDNIGHT AS A LOW LEVEL JET STREAK DEVELOPS OVER WEST KENTUCKY AT
06Z HOWEVER CAPE VALUES WILL BE LESS THAN 1000 J/KG. WILL HAVE THE
EVENING SHIFT KEEP A CLOSE EYE ON THIS SITUATION.

STORMS SHOULD MOVE GENERALLY EAST TOMORROW AND AS STORMS WEAKEN
IN THE MORNING...SOME SUNSHINE MAY CREATE SOME BETTER INSTABILITY
OVER THE EASTERN SECTIONS DURING THE AFTERNOON. SPC HAS PUT THE
AREA IN A SLIGHT RISK.

WE MOVE ALL OF THE PRECIPITATION OUT BY 06Z THURSDAY...BUT BRING
BACKS SHOWERS AND A FEW STORMS WITH A WAVE MOVING IN FROM THE
PLAINS DURING THE DAY ON THURSDAY. THESE WILL MAINLY BE OVER THE
SOUTHERN SECTIONS. MUCH LOWER DEW POINTS COME IN BEHIND THIS
SHORTWAVE WITH UPPER 40S DEW POINTS BY FRIDAY MORNING.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 245 PM CDT TUE MAY 21 2013

MODELS SHOW HIGH PRESSURE BUILDING SOUTH OUT OF CENTRAL/EASTERN
CANADA FRIDAY INTO FRIDAY NIGHT. THIS WILL LEAD TO DRY AND COOLER
THAN AVERAGE CONDITIONS. BY 12Z SATURDAY...ECMWF DIVERGES FROM THE
GEM AND GFS...SHOWING THE SURFACE HIGH MOVING FARTHER EAST AND A
WEAKER UPPER LEVEL RIDGE ACROSS THE CENTRAL U.S. THIS ALLOWS A
WEAK SURFACE BOUNDARY TO SET UP FROM EAST TO WEST ACROSS THE
MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS...THUS SHOWING SOME
PRECIP ACROSS THE REGION. GEM AND GFS...SHOWING THE STRONGER
SURFACE HIGH AND UPPER LEVEL RIDGE...KEEP THE BOUNDARY FARTHER
NORTH AND KEEP ANY PRECIP NORTH OF THE PAH FORECAST AREA UNTIL AT
LEAST LATE SUNDAY. GEM AND GFS HAVE BEEN MORE CONSISTENT AND
PREFER TO CONTINUE TO LEAN TOWARD THESE SOLUTIONS. WENT WITH
SLIGHT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS IN OUR EXTREME
NORTHERN COUNTIES ON SUNDAY...THEN CHANCE POPS NORTH TO SLIGHT
CHANCE POPS SOUTH SUNDAY NIGHT AS THE GFS SHOWS THE FRONT DIPPING
SOUTH. GFS THEN SHOWS THE UPPER LEVEL RIDGE SLIDING A LITTLE
FARTHER EAST AND BUILDING NORTH ON MONDAY...WHICH WILL HELP PUSH
THE FRONT BACK NORTH. WENT WITH SLIGHT CHANCE POPS SOUTHWEST TO
CHANCE POPS NORTHEAST ON MONDAY...WITH DRY CONDITIONS RETURNING BY
MONDAY NIGHT AND CONTINUING INTO TUESDAY.

WINDS WILL BECOME SOUTHERLY BY LATE SATURDAY.  AFTER A COOLER START
TO THE WEEKEND...THE SOUTH WINDS WILL LEAD TO GRADUALLY MODERATING
TEMPERATURES FROM SATURDAY THROUGH THE EARLY PART OF NEXT WEEK.
TEMPERATURES WILL REMAIN A LITTLE BELOW NORMAL SATURDAY...WITH NEAR
TO A LITTLE ABOVE SEASONAL READINGS SATURDAY NIGHT THROUGH
TUESDAY.

&&

.AVIATION...
ISSUED AT 1232 PM CDT TUE MAY 21 2013

VFR CONDITIONS EXPECTED THROUGH 00Z. SCT SHRA THROUGH 00Z WITH
LOW VFR CIGS AND MVFR VSBYS POSSIBLE. INCREASING TSTM CHANCES THIS
EVENING AND OVERNIGHT WITH PREDOMINANT MVFR CONDITIONS LIKELY.
GUSTY WINDS AND BRIEF HEAVY RAINFALL POSSIBLE WITH STORMS.  TSTMS
WILL DECREASE WEST TO EAST BETWEEN 08Z AND 13Z...WITH LOW VFR TO
MVFR CONDITIONS PERSISTING. WINDS WILL BE FROM THE SOUTH TO
SOUTHWEST AT 8 TO 14 KTS THROUGH THE TAF PERIOD...WITH GUSTS TO 20
TO 25 KTS THIS AFTERNOON.


&&

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

$$

SHORT TERM...PS
LONG TERM...RST
AVIATION...RST