Severe Thunderstorm Warning 57, NWS Jackson, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
300 PM EDT SAT MAY 27 2000

18Z SFC ANALYSIS SHOWS LOW PRESSURE CENTERED OVER IOWA WITH A WARM
FRONT STRETCHED EAST TO NORTHEAST KENTUCKY. A COLD FRONT RUNS SOUTH
OF THE LOW DOWN TO EAST OKLAHOMA. EAST KENTUCKY IS AWASH WITH
OUTFLOW BOUNDARIES FROM THE EARLIER CONVECTION. THE NEXT MCS ON OUR
SLATE IS JUST ENTERING THE SOUTHWEST PORTION OF KENTUCKY. HIGH
CLOUDS FROM THIS ARE SPREADING EAST AND WILL LIMIT OUR TEMPERATURE
RECOVERY LATE THIS AFTERNOON. HOWEVER...WE REMAIN IN AN UNSTABLE AND
MOISTURE LADEN ENVIRONMENT WITH THE WARM FRONT NEARBY...AS THE
OUTFLOW MOVES EAST ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS
POSSIBLE THIS EVENING.

AS FOR THE BIG PICTURE...AT 500 MB THE MODELS ARE IN GOOD AGREEMENT
EARLY ON BEFORE THE AVN RUNS OFF ON A TANGENT ATTEMPTING TO CUT OFF
THE SEMI-CLOSED LOW THAT ROLLS THROUGH THE OHIO VALLEY BY 36 HOURS.
THE ETA AND NGM ARE CONSISTENT WITH EACH OTHER AND THEIR PREVIOUS
RUNS KEEPING THE WAVE OPEN AND PROGRESSIVE ENOUGH TO MAKE IT TO THE
EAST COAST AT 48 HOURS. THE AVN ON THE OTHER HAND CUTS OFF THE LOW
OVER THE SOUTHERN APPALACHIANS AND KEEPS THE SOUTHEAST WET THROUGH
72 HOURS. IRONICALLY...DESPITE THESE STRIKING DIFFERENCES ALOFT THE
SFC PATTERN...RH AND QPF ARE SIMILAR IN TIME AND LOCATION ACROSS
EAST KENTUCKY. THE MODELS ALL TAKE THE SFC EAST THROUGH THE SOUTHERN
OHIO VALLEY TONIGHT...STRENGTHENING IT SUNDAY AS IT PASSES TO THE
NORTH. A COLD FRONT WILL WHIP ACROSS THE STATE LATE TONIGHT WITH
DRIER AIR TO FOLLOW DURING THE MORNING. A COUPLE OF VORTS SPIN
AROUND THIS LOW AND KEEP THE THREAT OF PRECIPITATION GOING SUNDAY
NIGHT.

AS FOR SENSIBLE WEATHER THE MAIN SHOW WILL BE TONIGHT. THIS EVENING
CONVECTION IS A GOOD BET...ESPECIALLY ACROSS THE SOUTH...AS THE
OUTFLOW BOUNDARIES AND ON GOING MCS PROGRESS EAST. THEN EXPECT A
LULL LATE THIS EVENING BEFORE ADDITIONAL CONVECTION AND MCS ACTIVITY
MOVES THROUGH TOWARD MORNING PUSHED BY THE LOWS COLD FRONT.
FOLLOWING THE FRONT THINGS WILL ATTEMPT TO DRY OUT FOR A TIME...
HOWEVER THE UPPER LOW BRINGS PLENTY OF DYNAMICS AND A COLD POOL TO
THE AREA FOR SUNDAY AFTERNOON CAUSING LIS TO FALL TO -9 WITH CAPES
APPROACHING 2000 J/KG. LOWERING WET BULB ZERO VALUES WILL GIVE US A
BETTER CHANCE OF HAIL AND DOWNBURST WINDS FROM THE CONVECTION
SUNDAY. EXPECT WRAP AROUND MOISTURE TO LINGER LIGHT PRECIPITATION
CHANCES THROUGH SUNDAY NIGHT. FOR NOW WILL TRY TO PLAY MEMORIAL DAY
DRY WITH JUST SOME MORNING LOW CLOUDS GOING TO CU BY AFTERNOON.
HOWEVER...IF THE AVN IS ON TO SOMETHING THEN SHOWERS WOULD REMAIN A
POSSIBILITY.

FLASH FLOOD WATCH CONTINUES TONIGHT AND INTO SUNDAY MORNING GIVEN
THE DEWPOINTS IN THE LOW 70S...PWS AROUND 1.75 INCHES...EXPECTED
ROUNDS OF CONVECTION THIS EVENING AND OVERNIGHT...AND SOAKED GROUND
FROM THE EARLIER MCS(S)

IN THE EXTENDED THE MODELS CONTINUE TO BE MUDDLED WITH THE MRF THE
BEST BET AT THIS TIME PER PMDEPD. AM CONCERNED ABOUT THE
POSSIBILITIES OF ADDITIONAL MCS ACTIVITY AS THE RIDGE BUILDS INTO
THE TENNESSEE VALLEY...BUT WILL LEAVE JUST PC FOR NOW.

FWC/FAN NUMBERS APPEAR REASONABLE AND WILL NOT STRAY FAR.

WORK ZONES AVAILABLE IN THE AFOS PRODUCT SDFOZFJKL. THANKS FOR THE
COORDINATION CALLS ILN AND RLX.

.JKL...FLASH FLOOD WATCH TONIGHT AND SUNDAY MORNING FOR THE ENTIRE
CWA.

GREIF