River Flood Warning 25, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
608 AM EST WED DEC 9 2009

...UPDATED AVIATION DISCUSSION...

.SHORT TERM (TODAY AND TONIGHT)...

...WINDY AND COLDER TODAY...

AT 07Z A DEEPENING SURFACE LOW WAS LOCATED OVER NORTHERN ILLINOIS
AND TRACKING QUICKLY NORTHEAST. A WARM FRONT EXTENDED EAST FROM THE
LOW INTO CENTRAL INDIANA AND SOUTHERN OHIO. KENTUCKY WAS IN THE WARM
SECTOR AND TEMPERATURES HAD WARMED INTO THE LOW AND MID 50S ACROSS
THE FORECAST AREA. A STRONG COLD FRONT WILL SWEEP ACROSS THE LOWER
OHIO VALLEY THIS MORNING AND USHER IN MUCH COLDER AIR.

WIND CONCERNS...

CHECKING THE LATEST ACARS SOUNDINGS FROM AIRCRAFT LANDING AT SDF WE
CONTINUE TO SEE A SLIGHT INVERSION IN THE LOWEST LEVELS OF THE
ATMOSPHERE. THIS INVERSION WILL SERVE TO KEEP THE 50+KT WINDS AT 3K
FT AGL FROM MAKING IT TO THE SURFACE EARLY THIS MORNING. ONCE THE
COLD FRONT SWEEPS ACROSS THE AREA THE INVERSION WILL BE GONE AND THE
STRONGER WINDS WILL SURFACE. BASED ON THE 00Z BUFKIT FORECAST
SOUNDINGS 50KTS CANNOT BE RULED OUT THIS MORNING... ESPECIALLY IN
THE HIGHER ELEVATIONS OF THE EASTERN PORTION OF THE FORECAST AREA.
WE WILL ISSUE A HIGH WIND ADVISORY ACROSS ALL THE FORECAST AREA FOR
TODAY.

PRECIPITATION...

ISOLATED THUNDERSTORMS HAVE DEVELOPED ACROSS THE FORECAST AREA THIS
MORNING ALONG A PRE-FRONTAL TROUGH. I DONT THINK WINDS ARE MAKING
IT TO THE GROUND BUT IT IS POSSIBLE AND SOME SMALL HAIL IS ALSO
POSSIBLE. ONCE THE COLD FRONT ARRIVES WE ONLY EXPECT SCATTERED
SHOWERS WITH THE PRECIPITATION CHANGING TO SOME LIGHT SNOW SHOWERS
OR FLURRIES LATE THIS MORNING AND AFTERNOON. NO SNOW ACCUMULATION IS
EXPECTED.

TEMPERATURES...

AS MENTIONED READINGS THIS MORNING WERE RUNNING IN THE LOW AND MID
50S SOUTH OF THE WARM FRONT. THE WARMEST TEMPERATURES OF THE DAY
WILL OCCUR JUST AHEAD OF THE PASSING COLD FRONT WITH DROPPING
TEMPERATURES LATE THIS MORNING AND AFTERNOON. READINGS BY EVENING
WILL RANGE FROM THE LOW MID 30S.

OVERNIGHT WE EXPECT THE WINDS TO GRADUALLY DIMINISH AS TEMPERATURES
FALL INTO THE UPPER TEENS AND LOWER 20S UNDER CLOUD SKIES.

.LONG TERM (THURSDAY - TUESDAY)...

THURSDAY THROUGH FRIDAY NIGHT...

SHORT-MED RANGE DETERMINISTIC AND ENSEMBLE MODEL RUNS ARE IN PRETTY
GOOD AGREEMENT THROUGH THIS TIME FRAME.  SFC HIGH PRESSURE IS FCST
TO QUICKLY BUILD INTO THE REGION ON THURSDAY PROVIDING THE AREA WITH
DRY AND GENERALLY COLD CONDITIONS.  EVEN WITH THE SUN OUT ON
THURSDAY...TEMPERATURES WILL STRUGGLE TO WARM INTO THE LOWER-MID 20S
IN THE NORTH WITH UPPER 20S TO NEAR 30 POSSIBLE ACROSS SOUTHERN
KENTUCKY.  GOOD RADIATIONAL COOLING IS EXPECTED THURSDAY NIGHT AND
FRIDAY MORNING AS SFC HIGH DRIFTS OVERHEAD.  NEAR CALM WINDS WILL
ALLOW TEMPERATURES TO FALL INTO THE LOWER-MID TEENS ACROSS SOUTHERN
INDIANA AND NORTHERN KY...WITH MID-UPPER TEENS LIKELY ACROSS
SOUTHERN KY.  IN SOME OF OUR MOST SHELTERED LOCATIONS...WE COULD SEE
TEMPS DROP AS LOW AS 9-11 DEG.  A SLIGHT MODERATION IN TEMPS SEEMS
INCREASINGLY LIKELY FOR FRIDAY WITH AFTERNOON READINGS WARMING INTO
THE LOWER-MID 30S IN THE NORTH WITH UPPER 30S TO NEAR 40 IN THE
SOUTH.  OVERNIGHT LOWS FRIDAY NIGHT WILL LIKELY DROP BACK INTO THE
LOWER-MID 20S ACROSS THE ENTIRE REGION UNDER PARTLY CLOUDY SKIES.

SATURDAY THROUGH TUESDAY...

MED-LONG RANGE MODEL SOLUTIONS HAVE BEEN SHOWING QUITE A BIT OF
SPREAD OVER THE LAST 3-4 RUNS AND CONSISTENCY HAS BEEN RATHER POOR.
JUST 24 HOURS AGO...THE GFS RUNS WERE SUGGESTING A POSSIBLE WINTRY
MIX OF PRECIPITATION ACROSS MUCH OF THE REGION DURING THE DAY ON
SATURDAY AS A SOUTHERN STREAM SYSTEM PUSHED SOUTH OF THE REGION.
THE GFS SOLUTIONS OVER THE PAST 3-4 RUNS HAVE TRENDED CLOSER TO THE
EURO SOLUTIONS IN THAT THEY ARE DRIER AND MUCH WARMER WITH THEIR
TEMPERATURE PROFILES.  FROM A SYNOPTIC STANDPOINT...I CAN SEE WHY
THE SOUTHERN STREAM IS MORE SUPPRESSED GIVEN THE RELATIVELY FAST
ZONAL FLOW UP AROUND 500 MB.  THIS SETUP WOULD TEND TO KEEP SYSTEMS
IN THE SOUTHERN STREAM FROM GAINING LATITUDE AND GENERALLY PASSING
SOUTH OF THE REGION.  AT THIS TIME...THE BEST CHANCES OF PRECIP SEEM
TO BE IN OUR REGION FOR SAT NIGHT AND SUNDAY AS THE SOUTHERN SYSTEM
WORKS THROUGH THE REGION.  THERMAL PROFILES ARE VERY CLOSE TO
CRITICAL VALUES. GIVEN THE POOR MODEL CONSISTENCY AND UNCERTAINLY
FEEL THE BEST OPTION RIGHT NOW IS TO KEEP RAIN/SNOW IN THE FCST FOR
SAT NIGHT.  SYSTEM LOOKS TO PULL OFF TO THE EAST ON SUNDAY WITH SOME
RAIN SHOWERS POSSIBLE AS THERMAL PROFILES CONTINUE TO BE WARM.
AFTER A BRIEF LULL...NEXT SYSTEM LOOKS TO IMPACT THE REGION MONDAY
NIGHT AND TUESDAY AS A COLD FRONT PUSHES THROUGH THE AREA.
AGAIN...BOTH THE 09/00Z GFS AND EURO ARE WARMER IN THEIR RUNS
SUGGESTING RAIN AT THE MOMENT.  GENERALLY KEPT HIGHS/LOWS THROUGH
THE PD CLOSE TO THE RAW 2M TEMPS FROM THE EURO AND GFS SOLUTIONS
HERE.  THIS RESULTS IN ONLY MINOR CHANGES TO THE ONGOING FCST.

&&

.AVIATION (12Z TAF ISSUANCE)...

GUSTY SOUTHWEST WINDS WILL CONTINUE TODAY AS A DEEP SURFACE LOW
TRACKS NORTHEAST THROUGH THE GREAT LAKES REGION. WIND GUST TO 55 MPH
MAY OCCUR THIS MORNING ESPECIALLY AT THE SDF AND LEX TAF SITES.
CLOUD BASES WILL BE AROUND 3K FT AGL THIS MORNING WITH LIGHT SHOWERS
OR SNOW SHOWERS POSSIBLE.  WINDS WILL BEGIN TO DIMINISH THIS EVENING.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...HIGH WIND WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
     KYZ023>043-045>049-053>057-061>067-070>078-081-082.

IN...HIGH WIND WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
     INZ076>079-083-084-089>092.

&&

SHORT TERM........JA
LONG TERM.........MJ
AVIATION..........JA

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE LOUISVILLE KY
502 AM EST WED DEC 9 2009

INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067-
070>078-081-082-101015-
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-
502 AM EST WED DEC 9 2009 /402 AM CST WED DEC 9 2009/

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

.DAY ONE...TODAY AND TONIGHT.

A COLD FRONT WILL SWEEP THROUGH THE REGION EARLY THIS MORNING
BRINGING STRONG WINDS TO THE REGION IN ITS WAKE. SUSTAINED SURFACE
WINDS OF 30 TO 40 MPH WILL BE POSSIBLE WITH GUSTS UP TO 55 MPH. A
HIGH WIND WARNING IS THUS IN EFFECT UNTIL 7PM EST.

TEMPERATURES WILL QUICKLY FALL IN THE WAKE OF THE FRONT AS WELL.
SNOW SHOWERS ARE FORECAST TO DEVELOP DURING THE AFTERNOON BUT NO
ACCUMULATIONS ARE EXPECTED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

A COUPLE OF WEATHER SYSTEMS WILL IMPACT THE REGION THROUGH THIS
TIME PERIOD. THE FIRST SYSTEM IS EXPECTED TO AFFECT THE REGION
SATURDAY AFTERNOON AND EVENING...AND THE SECOND ONE WILL AFFECT
THE AREA MONDAY NIGHT THROUGH TUESDAY. AT THIS TIME...ATMOSPHERIC
TEMPERATURES NEAR THE SURFACE ARE EXPECTED TO REMAIN WARM ENOUGH FOR
PRECIPITATION TO FALL AS RAIN...THOUGH A MIX OF RAIN/SNOW IS
POSSIBLE SATURDAY NIGHT AND EARLY SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ASKED TO REPORT INSTANCES OF WIND DAMAGE FROM STRONG
WINDS TODAY...AS WELL AS ANY RECORDED WIND GUSTS OR TREES OR POWER
LINES DOWNED.

JA/MJ