Severe Thunderstorm Warning 263, NWS Louisville, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1133 AM EDT Fri Jul 10 2015

...Forecast Update...
Issued at 1132 AM EDT Fri Jul 10 2015

Small, but intense bowing segment continues to push eastward across
north-central KY.  This storm did have supercellular characteristics
as it went through eastern Meade county, the Fort Knox area, and
through Bullitt county.  The cell has bowed out now with a bookend
vortex on the north side heading through Shelby county.  This will
head east-northeast through the rest of Shelby and into southern
Henry and western Franklin county over the next 30-45 minutes.

Convective line is moving steadily eastward at 45-48 knots.  Based
on this speed, it would impact the Lexington metro and the Kentucky
Horse Park area in the next 30-35 minutes.  We expect damaging winds
to be the primary threat with this activity...though an isolated
spinup could still occur.

Elsewhere, stratiform rain continues out behind the main convective
line.  This will continue to move eastward as well.  So the western
and southern areas of the forecast area will remain generally dry
for the next few hours.  Additional convection is likely to develop
across central and southern KY this afternoon.  This activity will
be aided by any outflows from the current convection going across
north-central and east-central KY and by strong surface heating.
Damaging winds will still be the primary threat.

Current Severe Thunderstorm Watch #400 is in effect until 400 PM
EDT.  Will be monitoring convective trends for any expansions or
extensions in time later this afternoon.

Issued at 947 AM EDT Fri Jul 10 2015

Early morning surface analysis reveals a surface frontal boundary
bisecting the region.  Convection out across southwest Indiana
continues to move eastward at a good clip.  The convection will help
re-enforce this boundary this morning and into the afternoon hours.
Heavy rainfall will be possible with this activity this morning.
The highest risk of heavy rain/flash flooding will generally be
north of a line from Hartford (Ohio County) to Georgetown (Scott
County).  Some of this convection may approach severe limits in the
next hour or so.  Model proximity soundings show a bit of a stable
layer near the surface up near the Ohio River.  However, as you get
closer to the WK and BG Parkways, the stable layer erodes a bit.

Once this convection moves out by late morning, we'll continue to
see a destabilization of the atmosphere during the afternoon hours.
A mid-level wave out across Missouri will move eastward across the
region this afternoon that will force ascent across the region.
Higher dewpoints to the south/southwest should advect northward into
the region which should allow decent instability to develop across
the region.   Afternoon CAPE values should approach 1700-2100 J/KG
combined with 35-40kts of bulk shear would be enough to produce
severe convection.  Downdraft CAPE (DCAPE) values are forecast from
our local and national high res WRF models to be in excess of 1000
J/KG, thus another round of wind damage looks to be in the cards
with this afternoon's convection.

Current thinking is that additional convection will fire along and
south of the WK and BG Parkways this afternoon and steadily move
eastward.  Convection looks to favor a mix of multi-cells and bowing
line segments containing damaging winds.  Area at most risk for
seeing severe weather this afternoon would be in areas along an
south of the Ohio River. A gradual weakening will occur later
tonight, but it will lag well behind sunset.

Given this mornings convection moving across southern Indiana and
the expected convection to develop across much of KY this afternoon,
have gone ahead and hoisted a Flash Flood Watch for the northern
2/3rds of the forecast area.  It does appear that we'll see a fine
gradient of where the rain does fall and areas down along the KY/TN
border may not see much rain at all...but once you head north of the
Cumberland Parkway, this afternoon's convection may end up being a
bunch of line segments training over the same areas...increasing the
flood threat.  QPF amounts of 1 to 2 inches will likely be common,
though isolated swaths of 3-4 inches are not out of the question
where training of convection occurs.

.SHORT TERM (Now through Saturday)...
Issued at 316 AM EDT Fri Jul 10 2015

5H shortwave trof over Missouri early this morning has been
producing showers and thunderstorms over the Show-Me State through
the night. Model guidance have a pretty good handle on this
feature, moving it eastward into the Ohio Valley today along the
edge of an expansive upper ridge over the southeast United States.
The SPC SREF and RAP have been verifying the best overnight and are
the models of choice for today.

Although the winds aloft will be slightly weaker today than
yesterday, and sounding progs suggest there won't be as much of a
dry layer aloft or as much DCAPE today compared to yesterday, there
is still come concern associated with the incoming disturbance. The
wave will be entering the region at or near peak heating with lifted
index values around -5C and CAPE in the vicinity of 2000 J/kg. There
will also be what is left of an old surface boundary draped
east-west roughly along the Ohio River, and precipitable water
numbers around two inches. So, robust thunderstorm development will
still be possible, and some of the storms could produce gusty winds.
Freezing levels are rather high for much of a large hail threat.
Though low level helicity and 0-6km bulk shear aren't particularly
impressive, storms near the surface boundary and storm interactions
will need to be watched for any signs of rotation.

Locally torrential downpours will be possible in the juicy
atmosphere. After discussion with ILN and JKL, decided to hold off
on a Flash Flood Watch for now. Most FFG numbers in the area of
potentially heavy rain are fairly high, and flash flooding problems
are expected to be local, under the heaviest cores. Nevertheless, if
training starts to become a problem, a headline may be issued later.

The presence of clouds and convection will greatly influence
temperatures today, but in general will aim for highs in the 80s.
Southern Kentucky will be south of the main shower/storm activity
for much of the day so 90 degrees will be attainable there once
again.

Tonight showers and storms will slowly diminish through the
overnight hours as the wave exits to the east. Lows will range from
the mid 60s to around 70.

On Saturday we will sit on the northeast edge of the retrograding
southern U.S. upper ridge. Isolated thunderstorm development can't
be entirely ruled out in this pattern, so will hold on to a small
chance of storms. The best chances will be from southern Indiana to
the northern Blue Grass, where the GFS and NAM12 show a weak wave
moving through. High temperatures will be in the middle 80s to
around 90.

.LONG TERM (Saturday Night through Thursday)...
Issued at 241 AM EDT Fri Jul 10 2015

The synoptic pattern Saturday night is expected to feature an upper
level ridge centered over Texas with embedded shortwave troughs
riding the periphery from the central Plains, Upper Midwest and
lower Great Lakes. At the surface, weak high pressure will be over
the local area with mild/humid conditions in place.

A complex of storms is likely to initiate across parts of the Upper
Midwest and lower Great Lakes Saturday night and then track
east/southeastward. The storm complex would likely be on a weakening
trend through the night and some of the guidance suggests it could
approach southern Indiana and parts of northern Kentucky by sunrise
Sunday morning. Given the uncertainty, kept POPs in the chance
range over southern Indiana and northern Kentucky. Otherwise, plan on
lows in the mid 60s to lower 70s.

For Sunday, another impulse in the upper levels will slide through
Indiana and Ohio during the afternoon/evening hours. Timing during
peak heating with modest instability values across the area should
yield scattered showers/storms, especially along and north of the KY
parkways. Highs mid 80s to low 90s, warmest across south-central
Kentucky where less clouds and a lesser chance of rain will exist.

Monday into much of next week, further retrogression of the upper
ridge will channel shortwave trough energy over the lower Ohio
Valley. Several impulses look to pass over the region, inducing
periodic rounds of showers/storms, some strong at times, throughout
the week. Timing these waves still pose a challenge, but for now,
model guidance in agreement showing one arriving Monday
afternoon/evening. Again, combination of peak heating, modest
instability and upper level support should fuel scattered storms,
some of which will be capable of producing stronger wind gusts.

For Tuesday through Thursday, model differences creep up as the
10.00z GFS is more unsettled showing numerous shortwaves in the
upper level flow. Meanwhile, the ECMWF is weaker with these
features. Will advertise 30-50 percent POPs each day with
temperatures right around normal. In between shortwaves, if clouds
clear out and timing is right, highs could easily reach the low/mid
90s especially across the south. This would make for some hot and
humid conditions with heat indices approaching 100 to 103 during the
afternoon. Plan on mild/muggy nights with lows in the upper 60s to
low/mid 70s.

&&

.AVIATION (12Z TAF Update)...
Updated at 635 AM EDT Fri Jul 10 2015

An upper wave sparking showers and thunderstorms early this morning
in Missouri will track east today. As it encounters unstable air and
interacts with what's left of a weak east-west surface boundary
across northern Kentucky, showers and storms will spread eastward
into the Commonwealth. SDF and LEX stand the best shot of
thunderstorms. Some of the storms may be strong to severe with gusty
winds and very heavy rain. Though prevailing conditions will be VFR,
individual storms will bring vsbys well below VFR.

Afternoon storms should move off to the east this evening, leaving
us with quiet weather tonight. We will again face the possibility of
patchy fog and/or low clouds towards morning.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH through late tonight FOR KYZ023>043-045>049-
     053>057-063>067.

IN...FLASH FLOOD WATCH through late tonight FOR INZ076>079-083-084-
     089>092.

&&

Update.........MJ
Short Term.....13
Long Term......ZT
Aviation.......13

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOUISVILLE KY
1055 AM EDT FRI JUL 10 2015

INZ076>079-083-084-089>092-KYZ023>032-063-064-111500-
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-HART KY-GREEN KY-
INCLUDING THE CITIES OF...PAOLI...SALEM...SCOTTSBURG...MADISON...
JASPER...MARENGO...TELL CITY...CORYDON...NEW ALBANY...
JEFFERSONVILLE...HAWESVILLE...HARDINSBURG...BRANDENBURG...
BEAVER DAM...LEITCHFIELD...ELIZABETHTOWN...FORT KNOX...
MOUNT WASHINGTON...SHEPHERDSVILLE...LOUISVILLE...LA GRANGE...
BEDFORD...MUNFORDVILLE...GREENSBURG
1055 AM EDT FRI JUL 10 2015 /955 AM CDT FRI JUL 10 2015/

...FLASH FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT...

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

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS ARE EXPECTED TODAY AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. THE MAIN THREATS FROM THE STORMS WILL BE GUSTY
WINDS AND LOCALLY VERY HEAVY RAINFALL. THE BEST CHANCES FOR STRONG
TO SEVERE STORMS WILL BE ALONG AND SOUTH OF THE OHIO RIVER THIS
AFTERNOON. THE VERY HEAVY RAINFALL MAY LEAD TO SOME LOCALIZED
FLOODING PROBLEMS. FOR THIS REASON...A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR TODAY THROUGH LATE THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ISOLATED TO SCATTERED STORMS WILL BE POSSIBLE THROUGH MUCH OF
THIS PERIOD AS A WEAK FRONTAL BOUNDARY STALLS IN THE REGION. THE
STRONGER STORMS WILL BE CAPABLE OF GUSTY WINDS AND LOCALLY HEAVY
RAIN.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY...ESPECIALLY THIS AFTERNOON
BETWEEN INTERSTATE 64 AND THE LOUIE B NUNN PARKWAY.

&&

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

KYZ033>043-045>049-053>057-065>067-111500-
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-TAYLOR KY-CASEY KY-LINCOLN KY-
INCLUDING THE CITIES OF...NEW CASTLE...SHELBYVILLE...FRANKFORT...
GEORGETOWN...CYNTHIANA...TAYLORSVILLE...LAWRENCEBURG...VERSAILLES...
LEXINGTON...PARIS...CARLISLE...BARDSTOWN...SPRINGFIELD...
HARRODSBURG...NICHOLASVILLE...WINCHESTER...HODGENVILLE...LEBANON...
DANVILLE...LANCASTER...RICHMOND...CAMPBELLSVILLE...LIBERTY...
STANFORD
1055 AM EDT FRI JUL 10 2015

...FLASH FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT...
...SEVERE THUNDERSTORM WATCH 400 IN EFFECT UNTIL 4 PM EDT THIS
AFTERNOON...

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

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS ARE EXPECTED TODAY AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. THE MAIN THREATS FROM THE STORMS WILL BE GUSTY
WINDS AND LOCALLY VERY HEAVY RAINFALL. THE BEST CHANCES FOR STRONG
TO SEVERE STORMS WILL BE ALONG AND SOUTH OF THE OHIO RIVER THIS
AFTERNOON. THE VERY HEAVY RAINFALL MAY LEAD TO SOME LOCALIZED
FLOODING PROBLEMS. FOR THIS REASON...A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR TODAY THROUGH LATE THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ISOLATED TO SCATTERED STORMS WILL BE POSSIBLE THROUGH MUCH OF
THIS PERIOD AS A WEAK FRONTAL BOUNDARY STALLS IN THE REGION. THE
STRONGER STORMS WILL BE CAPABLE OF GUSTY WINDS AND LOCALLY HEAVY
RAIN.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY...ESPECIALLY THIS AFTERNOON
BETWEEN INTERSTATE 64 AND THE LOUIE B NUNN PARKWAY.

&&

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

KYZ061-062-070>078-081-082-111500-
BUTLER KY-EDMONSON KY-LOGAN 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...MORGANTOWN...BROWNSVILLE...RUSSELLVILLE...
BOWLING GREEN...FRANKLIN...SCOTTSVILLE...GLASGOW...TOMPKINSVILLE...
EDMONTON...COLUMBIA...JAMESTOWN...BURKESVILLE...ALBANY
955 AM CDT FRI JUL 10 2015

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

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS ARE EXPECTED TODAY AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. THE MAIN THREATS FROM THE STORMS WILL BE GUSTY
WINDS AND LOCALLY VERY HEAVY RAINFALL. THE BEST CHANCES FOR STRONG
TO SEVERE STORMS WILL BE ALONG AND SOUTH OF THE INTERSTATE 64
CORRIDOR THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

ISOLATED TO SCATTERED STORMS WILL BE POSSIBLE THROUGH MUCH OF
THIS PERIOD AS A WEAK FRONTAL BOUNDARY STALLS IN THE REGION. THE
STRONGER STORMS WILL BE CAPABLE OF GUSTY WINDS AND LOCALLY HEAVY
RAIN.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY...ESPECIALLY THIS AFTERNOON
BETWEEN INTERSTATE 64 AND THE LOUIE B NUNN PARKWAY.

&&

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

MJ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1211 PM EDT FRI JUL 10 2015

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

1203 PM     TSTM WND GST     7 E VERSAILLES          38.04N 84.61W
07/10/2015  M47 MPH          FAYETTE            KY   ASOS

            GUST AT BLUEGRASS AIRPORT.

&&

MRC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1213 PM EDT FRI JUL 10 2015

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

1054 AM     TSTM WND DMG     3 SSW BARDSTOWN JUNCTION37.89N 85.72W
07/10/2015                   BULLITT            KY   PUBLIC

            TREES DOWN, AND ROOF BLOWN OFF BARN. FUNNEL
            CLOUD SEEN AT THE TIME.

&&

JBS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1214 PM EDT FRI JUL 10 2015

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

1211 PM     TSTM WND DMG     2 W MILLVILLE           38.13N 84.86W
07/10/2015                   WOODFORD           KY   DEPT OF HIGHWAYS

            FEW TREES DOWN IN THE NORTHERN PART OF
            WOODFORD COUNTY. TREE ACROSS SHORE ACRES
            ROAD. LIMBS DOWN IN SOUTHERN PART OF THE
            COUNTY.

&&

KW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1222 PM EDT FRI JUL 10 2015

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

1210 PM     TSTM WND DMG     BURGIN                  37.75N 84.76W
07/10/2015                   MERCER             KY   PUBLIC

            TREES DOWN.

&&

MRC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1227 PM EDT FRI JUL 10 2015

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

1210 PM     TSTM WND DMG     3 NW LEXINGTON          38.07N 84.50W
07/10/2015                   FAYETTE            KY   LAW ENFORCEMENT

            NUMEROUS TREES DOWN ON THE NORTH SIDE OF
            LEXINGTON. A POWER LINE DOWN ON NEWTOWN
            PIKE.

&&

MRC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
1233 PM EDT FRI JUL 10 2015

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

1206 PM     TSTM WND DMG     1 NE DUCKERS            38.18N 84.77W
07/10/2015                   FRANKLIN           KY   AMATEUR RADIO

            POWER LINES DOWN - HANGING ABOUT 6' ABOVE
            ROAD.

&&

JBS