Flash Flooding and Flooding in Kentucky, July 4 to 10, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
117 PM EDT THU JUL 04 2013

...Updated Aviation Discussion...
.FORECAST UPDATE...
Issued at 908 AM EDT Tue Jul 03 2013

Have updated grids this morning to reflect both observational
trends and the latest trends in guidance.  Radar continues to show
bands of moderate to locally heavy rainfall pushing north across the
region.  It appears that a heavier band in west central TN will
continue to push north towards the BWG area over the next few hours,
which may be where any flooding threat will be maximized in the near
term.  Due to the trends in the current rainfall and with the
westward shift of the heaviest rainfall in the guidance, will be
expanding the Flash Flood Watch one tier of counties westward.  Have
also tweaked the QPF grids a bit further west.  Still expect the
heaviest rainfall to fall across portions of south-central and
central KY.  In fact, the 04/06Z NAM gives over 7 inches by Friday
morning to south-central KY.  Think this may be overdone, but 3
inches appear likely, with locally 5+.

&&

.SHORT TERM (Now through Thursday Night)...
Issued at 325 AM EDT Wed Jul 4 2013

...A very wet Fourth of July expected for the Bluegrass and Lake
Cumberland Regions...

...Flash Flood Watch in effect from Today through Friday morning...

A highly amplified and anomalous pattern for early July features
strong ridging centered over Nevada and well offshore of Virginia,
with a deep and somewhat narrow trough extending from the upper
Midwest all the way south into Texas. This pattern has retrograded a
bit over the last day, and is now allowing a fetch of very moist air
with PWATs near two inches to back its way west towards central
Tennessee and Kentucky.

As moisture increases over the Commonwealth, central and eastern
Kentucky and Tennessee will become positioned in the right rear
quadrant of a meridional jet moving north through the Great Lakes.
The strength and position of this jet this time of year is highly
unusual and is more indicative of spring.

Lift from this upper jet and a weakly unstable tropical airmass will
combine to produce a widespread area of showers later this morning
across central and eastern Tennessee that will rapidly lift north
northeast and overspread Kentucky east of Interstate 65 by early
afternoon. Several meso-scale short range models, as well as the
most recent GFS and NAM, show widespread substantial rainfall today
and tonight across eastern Kentucky, with perhaps the axis of
heaviest rain lined up right along the Daniel Boone National Forest.

Wherever this axis sets up, 2 to 3 inches of rain is expected
through Friday morning with locally higher amounts possible where
thunderstorms manage to develop or where showers manage to train
over one area. Will continue the flash flood watch as is through
Friday morning.

Substantially less rain is likely across southwestern Indiana and
west of Interstate 65, where both lift and moisture will remain less
than points farther east. A sharp gradient of rainfall totals is
possible along the northwestern edge of this precipitation shield.

Under mostly cloudy skies, highs today will stay cool, especially
over our eastern counties, where they may top out only in the mid
70s. our warmest highs today will develop over southwestern Indiana
and across west central Kentucky.

Showers are likely this evening and overnight as well, again,
concentrated over our eastern counties. Showers will become more
scattered for Friday afternoon, and may depend on localized pockets
of greater instability created by partial sun. Localized heavy rain
is once again possible Friday underneath some of the stronger
storms. Highs Friday will rise into the lower 80s.

A hydrological section highlighting the potential for heavy rain is
below.

.LONG TERM (Friday night through Wednesday)...
Issued at 243 AM EDT Thu Jul 4 2013

At the beginning of the period the upper air pattern will be much
the same as what we will have seen for the prior several days with
strong ridging off the East Coast, a north-south trof from Lake
Superior to the western Gulf of Mexico, and another ridge over the
southwestern deserts.

Over the course of the weekend the trof will slowly lift into the
Great Lakes with the East Coast ridge building westward.  Then over
the first half of the new work week the trof will exit the picture
completely as the eastern ridge and southwestern ridge join up,
resulting in a band of upper ridging stretching from the middle
Atlantic through the southern mainland United States to Hawaii by
Tuesday/Wednesday.

The steady stream of Gulf moisture that began on the Fourth will
continue through Saturday night, and then get shunted off to the
east Sunday as the Plains trof starts pushing eastward.  Once that
happens we'll go back to a more diurnal convection regime with
scattered showers and thunderstorms developing in the afternoons and
tapering off by late evening.

Through Saturday night occasional waves moving up the east side of
the upper trof will act as triggers, with the axis of the trof
itself moving overhead Saturday night or Sunday.  Monday through
Wednesday the best nearby trigger will be an east-west surface front
extending from the Great Plains to the Great Lakes.  Most of the
activity associated with this system will be to our north and west.
However we'll still have high enough PWATs and dew points with
sufficient instability for scattered thunderstorm development here.
Will keep coverage low for now.

As that upper ridge establishes itself, we'll see a return to more
seasonably hot temperatures. Also, those high dew points will give a
muggy feeling to the warm air.  High temperatures over the weekend
will generally be around the lower 80s. Monday through Wednesday
will see afternoon readings peak more in the 85-90 degree range,
possibly even a degree or two warmer.  We won't get much relief at
night with lows around 70.

&&

.AVIATION (18Z TAF Update)...
Issued at 116 PM EDT Thu Jul 4 2013

Certainly not the best day for holiday flying, as numerous rain
showers across all sites are providing low cigs/vsbys.  As expected
in this pattern, cigs and visibilities have been rather chaotic.  It
appears as though the heaviest rainfall is still to come, and will
fall between the 04/21Z and 05/06Z timeframe.  However, any shower
before or after then will be capable of reducing ceilings and/or
visibilities into IFR thresholds.  It appears as though the worst
conditions will be at KLEX and KBWG, where the heavy rain axis is
expected to set up.  Looking over the past few hours, lightning has
been very sparse, thus will pull VCTS from the forecast.  A rogue
rumble of thunder is still possible, but a nearly saturated and warm
atmosphere does not support widespread thunder potential.

The heavier rainfall should taper off after about 06Z, but rain
will remain in the forecast.  Coverage remains a bit uncertain after
this timeframe, thus will just keep VCSH in after 06Z.  Regardless
of rainfall, some low stratus and/or light fog appears probable
tonight into Friday morning across all sites.  Conditions will
slightly improve after sunset, but showers and isolated
thunderstorms will remain in the forecast through the remainder of
the TAF period.

&&

.HYDROLOGY...
Issued at 338 PM EDT Wed Jul 3 2013

Latest forecast data continues to be in agreement with a tropical
fetch of moisture pooling up from the Gulf of Mexico into the Ohio
Valley through much of the forecast period.  Precipitable water
values are forecast to increase from about 1.3 inches to nearly two
inches by Thursday night and into Friday and beyond.  This combined
with a rich low-level airmass (dewpoints near 70) will result in
highly efficient, low-centroid storms developing producing
torrential rainfall.  While the ensemble probabilistic forecasts of
QPF have come down slightly from the 03/06Z to the 03/12Z runs,
there continues to be a fairly high probability of our region seeing
some 3-4 inches of rainfall from late tonight and into the weekend.
Locally higher amounts will be possible...especially where heavy
rains may train over areas.  Given the wet antecedent soil
conditions across the area...and expected rainfall amounts, we have
issued a Flash Flood Watch for much of Kentucky (mainly along and
east of I-65) through 12Z Friday.  Should future forecasts continue
to indicate heavy rains lasting into the weekend, an extension of
the watch may be required in future forecasts.

In addition to the flash flooding, should significant rainfall
develop across east-central and central Kentucky, significant rises
on the larger rivers and reservoirs in the area could occur.
This would include the following basins:

Kentucky River
Rolling Fork
Salt River
Licking River
Barren River
Green River

Persons living near creeks, streams, and typical flood prone areas
should keep abreast of water levels and be prepared to take action
if water starts to rise or if warnings are issued.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR INZ079-090>092.

KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ024>043-045>049-
     053>057-061>067-070>078-081-082.

Update...........KD
Short Term.......JSD
Long Term........13
Aviation.........KD
Hydrology........JSD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOUISVILLE KY
353 AM EDT THU JUL 4 2013

INZ076>079-083-084-089>092-KYZ023>026-061-070-050800-
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-BUTLER KY-LOGAN KY-
INCLUDING THE CITIES OF...PAOLI...SALEM...SCOTTSBURG...MADISON...
JASPER...MARENGO...TELL CITY...CORYDON...NEW ALBANY...
JEFFERSONVILLE...HAWESVILLE...HARDINSBURG...BRANDENBURG...
BEAVER DAM...MORGANTOWN...RUSSELLVILLE
353 AM EDT THU JUL 4 2013 /253 AM CDT THU JUL 4 2013/

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

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP TODAY AND CONTINUE
THROUGH THIS EVENING. ASIDE FROM CLOUD TO GROUND LIGHTNING...SOME
SHOWERS AND THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL
WITH PONDING ON AREA ROADWAYS.

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

FOR THE PERIOD FRIDAY THROUGH WEDNESDAY...SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS COULD OCCUR EACH DAY THROUGH THE PERIOD WITH
THE MOST WIDESPREAD PRECIPITATION EXPECTED ON FRIDAY. THE GREATEST
HAZARD FROM THESE STORMS ON FRIDAY WILL BE HEAVY RAINFALL THAT
COULD CAUSE LOCALIZED FLOODING IN SOME LOCATIONS. AS WITH ALL
THUNDERSTORMS...DANGEROUS CLOUD TO GROUND LIGHTNING WILL ALSO
OCCUR.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT ANY DANGEROUS WEATHER
CONDITIONS...INCLUDING FLOODING...TO THE NATIONAL WEATHER SERVICE.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT WEATHER.GOV/LOUISVILLE.

KYZ027>043-045>049-053>057-062>067-071>078-081-082-050800-
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-EDMONSON KY-HART KY-GREEN KY-
TAYLOR KY-CASEY KY-LINCOLN KY-WARREN KY-SIMPSON KY-ALLEN KY-
BARREN KY-MONROE KY-METCALFE KY-ADAIR KY-RUSSELL KY-CUMBERLAND KY-
CLINTON KY-
INCLUDING THE CITIES OF...LEITCHFIELD...ELIZABETHTOWN...FORT KNOX...
MOUNT WASHINGTON...SHEPHERDSVILLE...LOUISVILLE...LA GRANGE...
BEDFORD...NEW CASTLE...SHELBYVILLE...FRANKFORT...GEORGETOWN...
CYNTHIANA...TAYLORSVILLE...LAWRENCEBURG...VERSAILLES...LEXINGTON...
PARIS...CARLISLE...BARDSTOWN...SPRINGFIELD...HARRODSBURG...
NICHOLASVILLE...WINCHESTER...HODGENVILLE...LEBANON...DANVILLE...
LANCASTER...RICHMOND...BROWNSVILLE...MUNFORDVILLE...GREENSBURG...
CAMPBELLSVILLE...LIBERTY...STANFORD...BOWLING GREEN...FRANKLIN...
SCOTTSVILLE...GLASGOW...TOMPKINSVILLE...EDMONTON...COLUMBIA...
JAMESTOWN...BURKESVILLE...ALBANY
353 AM EDT THU JUL 4 2013 /253 AM CDT THU JUL 4 2013/

...FLASH FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...

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

.DAY ONE...TODAY AND TONIGHT.

WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP BY
MID TO LATE MORNING. THESE STORMS WILL BE TROPICAL IN NATURE WITH
LOCALIZED HEAVY RAINFALL THAT WILL PRESENT A THREAT OF FLASH
FLOODING. LOCALIZED HEAVY RAIN IS LIKELY FOR THIS AFTERNOON
THROUGH AT LEAST THIS EVENING...WITH SEVERAL INCHES OF RAIN
EXPECTED FOR THE BLUEGRASS AND LAKE CUMBERLAND REGIONS.

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

WIDESPREAD RAINFALL FROM THURSDAY THROUGH EARLY FRIDAY MAY BRING
RAPID RISES AND EVEN SOME FLOODING LATER THIS WEEKEND TO LARGER
RIVERS.

FOR THE PERIOD FRIDAY THROUGH WEDNESDAY...SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS COULD OCCUR EACH DAY THROUGH THE PERIOD WITH
THE MOST WIDESPREAD PRECIPITATION EXPECTED ON FRIDAY. THE GREATEST
HAZARD FROM THESE STORMS ON FRIDAY WILL BE HEAVY RAINFALL THAT
COULD CAUSE FLOODING IN SOME LOCATIONS. AS WITH ALL
THUNDERSTORMS...DANGEROUS CLOUD TO GROUND LIGHTNING WILL ALSO
OCCUR.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT ANY DANGEROUS WEATHER
CONDITIONS...INCLUDING FLOODING...TO THE NATIONAL WEATHER SERVICE.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT WEATHER.GOV/LOUISVILLE.

JSD/13