Flash Flooding in Kentucky, September 23, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
157 AM EDT SAT SEP 23 2006

.AVIATION...

CONVERGENCE BOUNDARY HAS SET UP ALONG THE OHIO RIVER AND HAS
BECOME A FOCUS FOR A LARGE COMPLEX OF SHOWERS AND THUNDERSTORMS.
THE MAJORITY OF CONDITIONS ALONG THIS LINE ARE STILL VFR OR MVFR
WITH CEILINGS HOLDING ABOVE 3000 FT...BUT SOME TEMPORARY
REDUCTIONS ARE POSSIBLE AS THERE ARE SOME EMBEDDED THUNDERSTORMS
IN THE MAIN RAIN SHIELD. HTS/PKB HAVE ALREADY STARTING RAINING AND
IT SHOULD SPREAD OVER THE REMAINDER OF SITES...CRW 7Z EKN 8Z BKW
10Z. BOTH MODELS SHOW GOOD INFLOW INTO THIS LINE OF STORMS SO THEY
SHOULD CONTINUE INTO THE MORNING HOURS SATURDAY BEFORE LIFTING
NORTHWARD INTO PA BY EARLY AFTERNOON. AS THE SHORTWAVE ENERGY THAT
IS DRIVING THE CONVECTION TO THE WEST NOW...ARRIVES BETWEEN 12Z
AND 18Z...EXPECT THE RAINFALL TO INTENSIFY AND THE CEILINGS SHOULD
FALL INTO THE MVFR/IFR RANGE. BY 19Z...EXPECT THAT THE MAIN BAND
OF RAIN WILL HAVE LIFTED NORTH OF THE REGION AND SHOULD SEE VFR
CONDITIONS RETURN AS THE REGION WILL BE TRULY IN THE WARM SECTOR.
CEILINGS SHOULD CLIMB TO AROUND 8K-10K FT.

AFTER 00Z...THE COLD FRONT TO THE WEST WILL BEGIN TO INVADE THE
REGION. SHOWERS COULD RETURN TO HTS/PKB BETWEEN 3Z AND 6Z. THEY
WILL HIT THE REMAINDER THE AREA AFTER 6Z.

&&

.PREV DISCUSSION...
 /ISSUED 827 PM EDT FRI SEP 22 2006/

AVIATION /00Z TO 00Z/...

CONVECTION AHEAD OF WARM FRONT MOVING ACROSS THE AREA HAVE
DIMINISHED IN INTENSITY AND COVERAGE MAINLY ACROSS THE EXTREME SOUTH
AND EASTERN MOUNTAINS. STILL SOME SHOWERS MOVING NORTHEAST ACROSS
SOUTHEAST OH AND CENTRAL WV. ADDITIONAL SHOWERS AND THUNDERSTORMS
CONTINUE MOVING EAST NORTHEAST ACROSS EASTERN AND NORTHERN KY.
HOWEVER...CAPE AND OTHER FORCING FEATURES SEEMS TO DIMINISH AND STAY
JUST WEST OF OUR CWA. KEPT -SHRA AT PKB AND HTS EXPECTING REMNANTS
OF THIS STRONG CONVECTION TO REACH SE OHIO OVERNIGHT.

OVERALL...MVFR/IFR CEILINGS AND MVFR VIS EXPECTED OVERNIGHT EXCEPT
TEMPORAL IFR VIS ALONG SHOWERS.

WARM FRONT WILL APPROACH TO THE AREA ON SAT BRINGING BACK GOOD
CHANCES OF SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE WESTERN AND
CENTRAL SITES WITH MORE CONFIDENCE AT PKB AND HTS ON SAT MORNING AND
AFTERNOON.

PREV DISCUSSION...
 /ISSUED 230 PM EDT FRI SEP 22 2006/

SHORT TERM /TONIGHT THROUGH SATURDAY/...

NEVER TRUST A WARM FRONT

NEAR DAWN THIS MORNING WE FIGURED THE BEST SHOT OF RAIN TODAY WOULD
LIFT OUT OF NE KY MORE TOWARD PKB AND SE OHIO.  BY 14Z...SAW THE
WRITING ON THE WALL...AND ADJUSTED POPS AND TEMPS...SINCE THE PCPN
FOLLOWED MORE ALONG WARM FRONT ALOFT...AND DEVELOPED E...WITH NRN
EDGE OF PCPN SHIELD BECOMING LIGHTER/SPOTTY.  HEAVIEST RAIN 15-19Z
HAS THUS BEEN ALONG ALONG I-64 AND A BIT S.  SOME .5 TO 1.0 INCHES
TODAY.

THAT SUPPORT LIFTS QUICKLY NE 21-00Z...SO WE CONTINUE TO THINK THE
AREAL COVERAGE IN THE SOUTH WILL DECREASE.

MORE SUPPORT ARRIVES OVERNIGHT INTO SE OHIO...SO POPS INCREASE
DURING THE NIGHT FOR SE OHIO.  MEANWHILE...TEMPERATURES WILL NOT
HAVE THEIR NORMAL DIURNAL TRACE...WITH READINGS STEADY THEN RISING
OVERNIGHT.

NO MAJOR CHANGES TO POP FIELD ON SATURDAY...WITH 60 PCT AND HIGHER
MAINLY FROM PKB-HTS ON W.  WITH 35-40 KNOTS FLOW AT 850 MB SATURDAY
AFTERNOON...SOME GUSTY WINDS ARE EASILY POSSIBLE IN SHOWERS.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...

COLD FRONT ENTERING NW INTO SUN MORNING. GOOD MIDLEVEL WINDS WITH
50-60 KT LLVL JET OFF BUFKIT PROFILES...CONTRIBUTING TO 0-6 KM SHEAR
TO 50 M/S SATURDAY NIGHT IN NORTHWESTERN CWA. SE OHIO MAY MERIT AN
HWO MENTION IN FUTURE ZONE PACKAGES FOR STRONG TSTORMS...LAYING IN
THE EASTERN FRINGE OF SPCS SLIGHT RISK. HOWEVER...WITH H7-H5 LAPSE
RATES BELOW 6C/KM AND EVEN MLCAPES MARGINAL...UPWARD MOTION WILL
LARGELY DEPEND UPON SHEAR.

FRONT PASSES THROUGH SUNDAY MORNING...AND SE COUNTIES MAY RUN WARMER
IF FRONT SLOWS DOWN A FEW HOURS. NOT MUCH OF A DIURNAL ELSEWHERE.
KEEP SLT CHC POPS LITTLE LONGER IN NW LATE SUNDAY AND PART OF SUNDAY
NIGHT WITH ADDITIONAL DISTURBANCE BEHIND FRONT AND SOME MOISTURE
LEFT OVER IN THE MIDLEVELS. FEW CHANGES MADE UP TO THIS POINT.

HIGH PRESSURE SETTLES IN FOR MUCH OF NEXT WEEK...BEFORE NEXT CHUNK
OF COOLER AIR APPROACHES LATE NEXT WEEK INTO NEXT WEEKEND WITH A
COLD FRONT CROSSING ON THURSDAY. LONG RANGE MODELS IN FAIR AGREEMENT
FOR DAYS 6 AND 7 WITH TROUGH OVER EAST...AND H85 TEMPS OFF THE MREF
NEAR 2 STD DEV BELOW NORMAL. HPC GUIDANCE WAS FOLLOWED...ALTHOUGH
FEEL MEX NUMBERS LOOK TOO WARM AT THE END OF THE LONG RANGE
CONSIDERING THE ABOVE.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&

AVIATION...ESS