Severe Thunderstorm Warning 207, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
730 AM EDT THU JUN 18 2009

UPDATED FOR SHORT TERM...

.SHORT TERM (TDA AND TONIGHT)...UPDATED

DERCHO MOVING ACROSS CWA AT THIS TIME HAS PRODUCED WIDESPREAD WIND
DAMAGE AND VERY HEAVY RAINFALL WITH ONLY ISOLATED REPORTS OF HAIL
OF 1 INCH.  SURFACE BOUNDARY EJECTING AHEAD OF LINE OF STORMS TO THE
SOUTHWEST PART OF CWA WILL PROVIDE FOCUS FOR REDEVELOPMENT W OF 1-65
THIS AFTERNOON WHILE CENTRAL TO SE CORNER OF CWA WILL EXPERIENCE
ONGOING CONVECTION AS BOWING SEGMENT RACES SOUTHEAST NEAR 50 MPH.

IN ADDITION TO DAMAGING WINDS...STREET FLOODING WILL OCCUR AS
RAINFALL RATES OF 2 INCHES PER HOUR HAVE BEEN REPORTED OVER 10-15
MINUTE TIME PERIODS.  RAPID MOVEMENT OF STORMS SHOULD REDUCE THREAT
FOR WIDESPREAD FLOODING.

PREVIOUS DISCUSSIONS FOLLOW...

LIKE YESTERDAY...WE SHUD DESTABILIZE WITH HEATING TO MODERATE TO
VERY UNSTABLE RANGES WITH SBCAPES LIKELY EXCEEDING 3000 J/KG AS
DEWPOINTS CLIMB TO THE LOWER/MID 70S DURG THE MORNING AFTER SUNRISE.
UNLIKE YESTERDAY...SCATTERED STORM DEVELOPMENT SHUD BE FOCUSED OVER
OUR NRN/ERN FA AS REMNANTS OF IA/WRN IL MCC DROP SEWD INTO OUR FA
TDA...LEAVING MESOSCALE BNDRYS TO GO ALONG WITH A SLOWLY NWD MOVG
SYNOPTIC BNDRY ACRS SRN INDIANA. WILL BUMP POPS A BIT ACRS THE N/E
TODAY TO ABOUT THE 40-45% RANGE...THIS IN LINE WITH OUR NEIGHBORS TO
THE N/NE/E. MODELS APPEAR TO BE UNDERPLAYING DEWPOINTS JUST A
BIT...WITH NAM FAVORED FOR TDA WITH AT LEAST SOME LO CHC MOS POPS
AND A BETTER REFLECTION OF IA/WRN IL MCC AT 06Z. FCST SOUNDINGS
AGAIN SHOW HIGH PRECIPITABLE WATER (ARND 1.75 INCH THRU THE DAY) AND
DRY MID LEVELS/40-50K FLOW...SUITABLE FOR BOTH SUPERCELLS
(SUFFICIENT BULK SHEAR) AND MULTICELLS (PULSING TO SVR LEVELS AT
TIMES) POSSIBLY CLUSTERING/EVOLVING INTO BOWING SEGMENTS. DAMAGING
WINDS AND LARGE HAIL SHUD BE EQUAL THREATS WITH PRIME TIME DURG THE
AFTN AND EARLY EVE.

WILL DROP POPS BY ABOUT 03Z TNGT WITH WANING INSTABILITY AND SUBTLE
HEIGHT RISES AS UPR LEVEL RIDGE BUILDS A BIT NEWD. LAST REMAINING
STORMS SHUD BE EXITING OUR ERN COUNTIES BY THEN.

WILL LEAVE MAX TEMPS ABOUT WHERE THEY WERE PREVIOUSLY FCST FOR
TDA...I.E. LOWER 90S WRN FA AND AROUND 90 EAST WITH SUNSHINE
FILTERING THRU HIGH CLOUDS THRU MID/LATE MORNING BEFORE CONVECTIVE
DEVELOPMENT BEGINS.

.LONG TERM (FRIDAY THROUGH WEDNESDAY)...

FRIDAY THROUGH SATURDAY...

THE MAIN CHALLENGE FOR THIS FORECAST PERIOD WILL BE TIMING/LOCATION
OF CONVECTION FRIDAY NIGHT INTO SATURDAY. THE MODELS OVER THE LAST
COUPLE RUNS HAVE TRENDED SLIGHTLY SLOWER AND A BIT FARTHER FROM THE
FORECAST AREA WITH THE SHORTWAVE EJECTING ACROSS THE GREAT LAKES
INTO THE NORTHEAST. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM LOOKS
TO TRAVERSE THE FORECAST AREA SATURDAY MORNING TO EARLY AFTERNOON.

AHEAD OF THIS FRONT IT IS LOOKING MORE LIKELY THAT A SIGNIFICANT
WEATHER SYSTEM IN THE FORM OF A SQUALL LINE WILL DEVELOP OVERNIGHT
FRIDAY INTO SATURDAY ACROSS THE OHIO VALLEY. THE MAIN THREAT FOR
SEVERE WEATHER WILL BE OVER SOUTHERN INDIANA BETWEEN 00-12Z
SATURDAY...WITH A SLIGHT POSSIBILITY OF THIS ACTIVITY REACHING JUST
SOUTH OF THE OHIO RIVER INTO NORTH CENTRAL KENTUCKY. AFTER
12Z...WILL MAINTAIN SLIGHT CHANCE TO CHANCE POPS THROUGH THE DAY
SATURDAY AS THE FRONT SAGS SOUTHWARD.

TEMPERATURES ON FRIDAY LOOK TO BE VERY WARM.  THE LATEST GFS RUN
SHOWS HIGHS IN THE UPPER 90S WITH DEWPOINTS AROUND 70 ON FRIDAY.
FEEL THIS MAY BE A LITTLE OVERDONE SO WILL STICK WITH GOING FORECAST
OF LOWER TO MID 90S WITH DEWPOINTS AROUND 70. THIS WILL RESULT IN
OUR WARMEST DAY THIS YEAR WITH THE HEAT INDEX HOVERING AROUND 100
DURING THE WARMEST PART OF THE DAY. THE PASSAGE OF THE COLD FRONT
WILL DROP HIGHS BACK INTO THE UPPER 80S ON SATURDAY.

.SUNDAY THROUGH WEDNESDAY...

THE MODELS DISAGREE SLIGHTLY WITH THE SETUP FOR SUNDAY...WITH THE
GFS LINGERING THE FRONTAL BOUNDARY ACROSS THE FORECAST AREA ALONG
WITH PRECIPITATION. FOR NOW WILL KEEP THE FORECAST DRY SUNDAY
THROUGH WEDNESDAY. TEMPERATURES THIS PERIOD WILL BE QUITE SUMMERLIKE
WITH HIGHS IN THE UPPER 80S/LOWER 90S AND LOWS IN THE UPPER 60S.

&&

.AVIATION (12Z TAFS)...

REMNANTS OF IL MCC WILL MOVE SEWD INTO OUR REGION TODAY LEAVING
OUTFLOW BNDRYS TO GENERATE NEW STORM DEVELOPMENT TDA DURG MAX
HEATING IN CONTINUED VERY MOIST/UNSTABLE AMS. SLOW NWD MOVG SFC
BNDRY OVER SRN INDIANA WILL ADD WEAK CONVERGENCE OVER OUR NRN MOST
REGION FOR STORM DEVELOPMENT. TSTMS SHUD BE SCATTERED IN
CLUSTERS...WITH THE MOST NUMEROUS CELLS ACRS OUR NRN/ERN
FA...INCLUDING SDF AND LEX. SCT NATURE OF STORMS PREVENTS MORE THAN
A VCNTY REMARK AT THIS TIME. ANY TAF SITE UNDER THE CORE OF A STORM
WILL LIKELY SEE BRIEF LIFR TO IFR VSBY AND MVFR CIG IN HEAVY RAIN.

STORMS SHUD BE DISSIPATING/MOVG EAST OF OUR REGION BY 00Z THIS
EVE...FOLLOWED BY DECREASING CLOUDS AND LIGHT S/SW FLO.

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&

SHORT TERM....KIRKPATRICK
LONG TERM.....EES
AVIATION......JDA/DK
UPDATE........JBS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOUISVILLE KY
820 AM EDT THU JUN 18 2009

INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067-
070>078-081-082-190830-
ORANGE IN-WASHINGTON IN-SCOTT IN-JEFFERSON IN-DUBOIS IN-
CRAWFORD IN-PERRY IN-HARRISON IN-FLOYD IN-CLARK IN-HANCOCK KY-
BRECKINRIDGE KY-MEADE KY-OHIO KY-GRAYSON KY-HARDIN KY-BULLITT KY-
JEFFERSON KY-OLDHAM KY-TRIMBLE KY-HENRY KY-SHELBY KY-FRANKLIN KY-
SCOTT KY-HARRISON KY-SPENCER KY-ANDERSON KY-WOODFORD KY-
FAYETTE KY-BOURBON KY-NICHOLAS KY-NELSON KY-WASHINGTON KY-
MERCER KY-JESSAMINE KY-CLARK KY-LARUE KY-MARION KY-BOYLE KY-
GARRARD KY-MADISON KY-BUTLER KY-EDMONSON KY-HART KY-GREEN KY-
TAYLOR KY-CASEY KY-LINCOLN KY-LOGAN KY-WARREN KY-SIMPSON KY-
ALLEN KY-BARREN KY-MONROE KY-METCALFE KY-ADAIR KY-RUSSELL KY-
CUMBERLAND KY-CLINTON KY-
820 AM EDT THU JUN 18 2009 /720 AM CDT THU JUN 18 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
INDIANA AND CENTRAL KENTUCKY.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED STRONG THUNDERSTORMS ARE EXPECTED TO DROP INTO SOUTHERN
INDIANA AND NORTH CENTRAL KENTUCKY THIS MORNING. THE STRONGEST
STORMS WILL BE CAPABLE OF PRODUCING STRONG AND GUSTY WINDS...LARGE
HAIL... FREQUENT CLOUD TO GROUND LIGHTNING AND A PERIOD OF VERY
HEAVY RAIN. ADDITIONAL STRONG STORMS WILL BE POSSIBLE THIS AFTERNOON
ACROSS SOUTH CENTRAL INDIANA AS WELL AS NORTH CENTRAL AND EAST
CENTRAL KENTUCKY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

ON FRIDAY...AFTERNOON HIGH TEMPERATURES ARE FORECAST TO BE IN THE
LOWER AND MID 90S. GIVEN EXPECTED HUMIDITY LEVELS...MAXIMUM
AFTERNOON HEAT INDICES WILL RISE TO AROUND 100. THEREFORE...EXTRA
CAUTION AND PLENTY OF WATER ARE ADVISED IF OUTSIDE FOR EXTENDED
PERIODS OF TIME.

A COLD FRONT WILL APPROACH THE AREA LATE FRIDAY NIGHT INTO SATURDAY
MORNING. A LINE OF THUNDERSTORMS IS EXPECTED TO DEVELOP OVER THE
NORTHERN OHIO VALLEY FRIDAY EVENING AND MOVE SOUTHEAST TOWARD
SOUTHERN INDIANA AND NORTH-CENTRAL KENTUCKY AFTER MIDNIGHT. THESE
STORMS WILL HAVE THE POTENTIAL TO BE SEVERE WITH DAMAGING WINDS THE
MAIN HAZARD...ALONG WITH BRIEF HEAVY RAINFALL AND FREQUENT CLOUD TO
GROUND LIGHTNING. THE BEST CHANCE FOR SEVERE WEATHER WILL BE OVER
SOUTHERN INDIANA.

SCATTERED THUNDERSTORMS WILL BE POSSIBLE SATURDAY OVER SOUTHERN
INDIANA AND CENTRAL KENTUCKY AS A COLD FRONT SAGS SOUTHWARD. ANY
STORMS THAT DEVELOP COULD PRODUCE GUSTY WINDS...HEAVY RAIN...AND
DANGEROUS CLOUD TO GROUND LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND AGAIN FRIDAY
NIGHT.

DK/EES/JA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1033 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

1005 AM     TSTM WND DMG     CHAMBERSBURG            38.52N  86.38W
06/18/2009                   ORANGE             IN   TRAINED SPOTTER

            TREE DAMAGE

&&

EVENT NUMBER LMK0900064

JMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1035 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0954 AM     TSTM WND DMG     ORLEANS                 38.66N  86.45W
06/18/2009                   ORANGE             IN   TRAINED SPOTTER

            LIMBS DOWN ALL OVER ORLEANS...MAX DIAMETER 1 FOOT

&&

EVENT NUMBER LMK0900065

JMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1037 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

1036 AM     TSTM WND GST     FLOYDS KNOBS            38.32N  85.87W
06/18/2009  E60 MPH          FLOYD              IN   TRAINED SPOTTER

&&

EVENT NUMBER LMK0900066

JMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1039 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

1025 AM     TSTM WND GST     MARTINSBURG             38.45N  86.03W
06/18/2009  E65 MPH          WASHINGTON         IN   ESPOTTER

&&

EVENT NUMBER LMK0900067

JMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1042 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

1041 AM     TSTM WND GST     FLOYDS KNOBS            38.32N  85.87W
06/18/2009  E70 MPH          FLOYD              IN   BROADCAST MEDIA

&&

EVENT NUMBER LMK0900068

JMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1044 AM EDT THU JUN 18 2009

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

1042 AM     TSTM WND DMG     NEW ALBANY              38.30N  85.83W
06/18/2009                   FLOYD              IN   BROADCAST MEDIA

            POWER LINES DOWN

&&

EVENT NUMBER LMK0900069

JMW