Special Weather Statement, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
759 PM EDT SUN SEP 25 2011

...MESOSCALE AND AVIATION UPDATE...

DIFFERENTIAL HEATING BOUNDARY HAS SET UP ROUGHLY FROM WEST OF KBWG
TO WEST OF KFFT...AS CLOUD COVER TODAY PROVIDED MUCH COOLER
TEMPERATURES NORTHWEST OF THAT LINE. HIGHS IN SOUTHWEST INDIANA WERE
AROUND 60...WHEREAS POINTS IN THE LAKE CUMBERLAND AREA REACHED
AROUND 80. SUBSEQUENTLY...A WIND SHIFT HAS OCCURRED WITH
NORTH/NORTHWESTERLY WINDS IMMEDIATELY WEST OF THE LINE AND
SOUTHEASTERLY WINDS BEHIND IT.

THE CONVERGENCE ASSOCIATED WITH THIS LINE ALONG WITH THE SHORTWAVE
FORCING ALOFT...COMING AROUND THE BASE OF AN ANOMALOUSLY STRONG
CUTOFF LOW CENTERED OVER EASTERN IOWA....WILL MEAN NEAR CERTAIN
CHANCES FOR RAIN OVER MOST OF THE REGION. GIVEN COVERAGE OF
THUNDERSTORM/S OVER PAH/S FORECAST AREA...HAVE BUMPED UP TO
SCATTERED COVERAGE FOR STORMS OVERNIGHT.

AREA SOUNDINGS INDICATE THAT THESE STORMS SHOULD REMAIN ELEVATED.
SO...DESPITE A 50-KT 850 MB JET MOVING ACROSS THE REGION
OVERNIGHT...AS DEPICTED BY VWP/S OUT OF KPAH AND KHPX...WINDS SHOULD
STAY DOWN. ACTUALLY MAY HAVE SOME STRONGER GRADIENT WINDS OVER THE
NEXT FEW HOURS AS THE SURFACE LOW DEVELOPS OVER WESTERN KENTUCKY
THIS EVENING AND MOVES NORTH NORTHEAST INTO INDIANA AFTER MIDNIGHT.
WILL CONTINUE TO MONITOR AS THE STRONGER CELLS MAY BE ABLE TO MIX A
PORTION OF THESE WINDS DOWN.

.SHORT TERM (TONIGHT AND MONDAY)...

THE CENTER OF THE PERSISTENT CUTOFF LOW CAN BE SEEN IN WATER VAPOR
IMAGERY CURRENTLY OVER NORTHERN IL/EASTERN IA. THIS WILL CONTINUE TO
WOBBLE AROUND THAT AREA THROUGH THE SHORT TERM. A SURFACE LOW IS
CURRENTLY OVER SE ARKANSAS AND THIS WILL MOVE TO THE NORTHEAST
TONIGHT INTO WESTERN KY...THEN SOUTHERN INDIANA AND WILL EVENTUALLY
ROTATE BACK INTO NORTHERN ILLINOIS. THIS SYSTEM WILL SWING A COLD
FRONT THROUGH THE FORECAST AREA OVERNIGHT.

SHOWERS HAVE BEEN ONGOING ACROSS PORTIONS OF SOUTHERN INDIANA
THROUGH THE DAY TODAY. THIS WILL CONTINUE THROUGH THIS AFTERNOON.
ADDITIONALLY...LIGHT SHOWERS WITH SOME EMBEDDED THUNDERSTORMS WILL
MOVE INTO WEST CENTRAL KENTUCKY OVER THE NEXT FEW HOURS.
HOWEVER...THE MAIN LINE WITH HEAVIER RAINS LOOKS LIKE IT WILL MOVE
INTO THE AREA AROUND 01-03Z TONIGHT. THIS LINE WILL SLOWLY TRACK
ACROSS THE FORECAST AREA OVERNIGHT. IT DOES LOOK LIKE IT WILL WEAKEN
SOMEWHAT AS IT MOVES EAST WITH LIGHTER RAINS EXPECTED OVER THE
EASTERN PORTION OF THE FORECAST AREA. THE HIGHEST RAINFALL AMOUNTS
THEREFORE WILL BE IN THE FAR WESTERN PORTION OF THE AREA WHERE UP TO
TWO INCHES OF RAIN WILL BE POSSIBLE. IN THE EAST UP TO AN INCH OF
RAIN WILL BE POSSIBLE WITH 1-1.5 INCHES FOR AREAS IN BETWEEN. THOUGH
FLASH FLOODING IS NOT EXPECTED WITH THESE RAINS SOME PONDING OF
WATER AND QUICK RISES ON SMALL STREAMS MAY OCCUR.

AS TO THUNDERSTORMS...THIS SYSTEM WILL HAVE LITTLE TO NO INSTABILITY
WITH IT AND WHAT LITTLE INSTABILITY THERE IS IS ELEVATED.
HOWEVER...A STRONG LOW LEVEL JET WILL DEVELOP OVERNIGHT. WINDS AT
850 MB WILL INCREASE TO 60+ KNOTS WHILE WINDS AT 2 KFT WILL INCREASE
TO 45-50 KT. SOME EMBEDDED THUNDERSTORMS WILL BE POSSIBLE WITH THE RAIN.
IF THEY ARE ABLE TO MIX THE LOW LEVEL WINDS DOWN THERE COULD BE SOME
ISOLATED DAMAGING WIND GUSTS. HOWEVER...WIDESPREAD SEVERE WEATHER IS
NOT EXPECTED.

THE RAIN WILL END FROM WEST TO EAST TOMORROW WITH DRIER AIR
FILTERING IN. SKIES WILL BECOME PARTLY CLOUDY. TEMPERATURES WILL TOP
OUT IN THE LOWER 70S.

.LONG TERM (MONDAY NIGHT - SUNDAY)...

THE UPPER LOW THAT WE HAVE BEEN TALKING ABOUT FOR A WHILE NOW WILL
BE CENTERED OVER NORTHERN ILLINOIS AT THE START OF THE LONG TERM
PERIOD. IT IS EXPECTED TO DRIFT INTO LOWER MICHIGAN BY WEDNESDAY
MORNING AND THEN ON INTO ONTARIO...EVENTUALLY GETTING ABSORBED BY A
DEEP UPPER TROF SWINGING THROUGH SOUTHEAST CANADA LATE THIS WEEK. AS
THE LOW SLOWLY DEPARTS OUR RAIN CHANCES WILL DEPART WITH IT. FOR NOW
IT APPEARS THAT SOME PATCHY LIGHT RAIN WILL STILL BE
POSSIBLE...PARTICULARLY IN SOUTHERN INDIANA AND NORTHERN
KENTUCKY...THROUGH TUESDAY NIGHT. THE BEST CHANCES BY FAR WILL BE
MONDAY NIGHT BUT EVEN THEN GENERAL RAINFALL AMOUNTS LOOK TO BE ON
THE ORDER OF A TENTH OF AN INCH OR LESS.

SURFACE HIGH PRESSURE TRAVELING ALONG THE U.S./CANADA BORDER
WEDNESDAY THROUGH FRIDAY WILL TURN SOUTHEAST INTO THE OHIO VALLEY
FOR THE WEEKEND...GIVING US DEEP BLUE SKIES AND CRISP AUTUMN
TEMPERATURES FOR THE FIRST TWO DAYS OF OCTOBER.

FOR THE WORK WEEK HIGHS WILL GENERALLY BE IN THE 70S WITH THE
EXCEPTION OF THURSDAY WHEN THE LOW WILL HAVE MOVED FAR ENOUGH TO THE
NORTHEAST BUT THE CANADIAN HIGH COMING IN FROM THE NORTHWEST WON/T
BE TOO CLOSE YET AND TEMPERATURES MAY BE ABLE TO GET INTO THE LOWER
80S. HIGHS OVER THE WEEKEND WILL BE A FEW DEGREES EITHER SIDE OF 70.
LOWS WILL BE IN THE 50S DURING THE WORK WEEK AND THE 40S THIS
WEEKEND. THERE IS A POSSIBILITY OF A FEW OF THE USUAL COLD SPOTS
DIPPING SLIGHTLY INTO THE UPPER 30S BY SUNDAY MORNING OR MONDAY
MORNING IF THAT CANADIAN HIGH COMES RIGHT OVERHEAD.

&&

.AVIATION (00Z TAF ISSUANCE)...

FIRST OFF...NORTH/NORTHWESTERLY WINDS AT KSDF APPEAR TO BE RELATED
TO A WARM FRONT THAT SET UP NORTHEAST OF THE LOW PRESSURE DEVELOPING
NEAR THE MISSOURI BOOTHEEL. THIS FRONT WAS ENHANCED BY TEMPERATURE
DIFFERENCES OVER THE REGION...WHICH WITH SUNSET AND A STRENGTHENING
SOUTHERLY FLOW SHOULD WEAKEN OVER THE NEXT COUPLE OF HOURS.

AS FOR THE RAIN EVENT...THE HEAVIER RAINS ARE JUST WEST OF THE TAF
SITES AT THIS TIME. HAVE SOME ISOLATED EMBEDDED STORMS. BEST TIMING
FOR ONSET OF STORMS OVERNIGHT WILL BE 03-10Z AT KSDF AND KBWG AND A
LITTLE LATER AT KLEX. FOR NOW HAVE PREVAILING NEAR MVFR CONDITIONS
DURING THOSE PERIODS WITH SOME SLIGHTLY STRONGER GUSTS. MAY HAVE
BRIEF PERIODS OF IFR VSBY/S AS THE HEAVIER RAINS MOVE QUICKLY
THROUGH. FLOW ALOFT WILL BE STRONG FROM THE SOUTH SO HAVE LLWS IN
THE FORECASTS FOR THE OVERNIGHT HOURS.

CONDITIONS SHOULD IMPROVE RAPIDLY MONDAY MORNING AS DRIER AIR WRAPS
AROUND THE SLOW-MOVING UPPER LOW NOW CENTERED OVER EASTERN IOWA.

&&

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

MESOSCALE......RJS
SHORT TERM.....EER
LONG TERM......13
AVIATION.......RJS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOUISVILLE KY
339 PM EDT SUN SEP 25 2011

INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067-
070>078-081-082-261945-
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-
339 PM EDT SUN SEP 25 2011 /239 PM CDT SUN SEP 25 2011/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

WIDESPREAD SHOWERS WITH ISOLATED EMBEDDED THUNDERSTORMS WILL
OVERSPREAD THE AREA FROM WEST TO EAST THIS EVENING. ANY
THUNDERSTORMS WILL HAVE GUSTY WINDS AND DANGEROUS LIGHTNING.

HEAVY RAIN UP TO 2 INCHES IS POSSIBLE ACROSS SOUTHWESTERN INDIANA
AND WEST CENTRAL KENTUCKY. WHILE THIS AMOUNT OF RAIN IS NOT
EXPECTED TO BRING ANY FLOODING...SOME RAPID RISES ACROSS SMALL
STREAMS AND PONDING OF WATER ON ROADWAYS ARE POSSIBLE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE THROUGH MID DAY
MONDAY. ANY THUNDERSTORM WILL HAVE GUSTY WINDS AND DANGEROUS LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

EER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LOUISVILLE KY
827 PM EDT SUN SEP 25 2011

INZ089-260100-
PERRY-
727 PM CDT SUN SEP 25 2011

...STRONG THUNDERSTORM WITH DANGEROUS LIGHTNING...HEAVY RAIN...HALF
INCH HAIL...AND 50 MPH WINDS NEARING WESTERN PERRY COUNTY INDIANA...

AT 724 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 6 MILES NORTH OF GRANDVIEW...AND MOVING NORTHEAST
AT 50 MPH.

FREQUENT CLOUD TO GROUND LIGHTNING...HEAVY RAIN WITH RAINFALL RATES
OF AROUND ONE INCH PER HOUR REDUCING VISIBILITIES TO LESS THAN ONE
MILE...HALF INCH HAIL...AND STRONG GUSTY WINDS OF AROUND 50
MPH...ARE EXPECTED WITH THIS STORM.

* THIS STORM WILL ALSO IMPACT...
  ADYEVILLE...
  BRISTOW AND SASSAFRAS...
  CELINA AND APALONA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...SEEK SHELTER INDOORS AND STAY
AWAY FROM WINDOWS. STAY TUNED TO NOAA ALL HAZARDS RADIO...
WEATHER.GOV/LOUISVILLE ON THE INTERNET...OR LOCAL MEDIA FOR LATER
UPDATES AND POSSIBLE WARNINGS.

&&

LAT...LON 3801 8680 3801 8678 3808 8678 3810 8677
      3811 8681 3818 8681 3820 8680 3826 8666
      3826 8663 3807 8650 3798 8679 3800 8681
TIME...MOT...LOC 0027Z 240DEG 37KT 3804 8696

RS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LOUISVILLE KY
913 PM EDT SUN SEP 25 2011

INZ076-077-084-090-260145-
CRAWFORD-HARRISON-ORANGE-WASHINGTON-
913 PM EDT SUN SEP 25 2011

...STRONG THUNDERSTORM WITH DANGEROUS LIGHTNING...HEAVY RAIN...HALF
INCH HAIL...AND 40 MPH WINDS...

AT 908 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR ENGLISH...AND MOVING NORTHEAST AT 50 MPH.

OCCASIONAL LIGHTNING...HEAVY RAIN WITH RAINFALL RATES OF AROUND ONE
INCH PER HOUR REDUCING VISIBILITIES TO LESS THAN ONE MILE...HALF INCH
HAIL...AND GUSTY WINDS OF AROUND 40 TO 45 MPH...ARE EXPECTED WITH
THIS STORM.

* THIS STORM WILL ALSO IMPACT...
  PAOLI...
  ENGLISH...
  VALEENE AND PINE VALLEY...
  REGO AND HARDINSBURG...
  MILLERSBURG AND MAHAN CROSSING...
  ROSEBUD AND LIVONIA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...SEEK SHELTER INDOORS AND STAY
AWAY FROM WINDOWS. STAY TUNED TO NOAA ALL HAZARDS RADIO...
WEATHER.GOV/LOUISVILLE ON THE INTERNET...OR LOCAL MEDIA FOR LATER
UPDATES AND POSSIBLE WARNINGS.

&&

LAT...LON 3846 8599 3843 8600 3824 8654 3838 8665
      3869 8633 3869 8631 3871 8631 3877 8626
TIME...MOT...LOC 0113Z 227DEG 44KT 3837 8647

RS