Special Weather Statement, NWS Louisville, KY

Area Forecast Discussion
National Weather Service Louisville KY
220 PM EDT Thu Jul 17 2025

.KEY MESSAGES...

* An active weather day is expected across the region with scattered
  to numerous showers and thunderstorms expected this afternoon and
  evening.  Storms could have strong downburst/microbursts resulting
  in localized damaging winds.

* Torrential rainfall is expected with the storms this afternoon and
  flash flooding may occur. The highest risk of flash flooding will
  be across SE Indiana and into the Bluegrass region.

* Outside of storms, near advisory levels of heat/humidity are
  expected with afternoon heat index readings reaching the upper 90s
  to the lower 100s.

* A continued active pattern continues into the weekend and early
  next week, with daily chances for showers and storms. Hot and
  humid weather is also expected to continue.

&&

.UPDATE...
Issued at 1138 AM EDT Thu Jul 17 2025

Conditions are already hot and humid late this morning. Heat indices
have risen into the mid 90s to around 100. Radar remains fairly
quiet - we've just had some isolated shower activity recently. Weak
frontal boundary is draped just north of the CWA across southern
portions of IN and IL. Already seeing up to 2500-3000 J/kg MLCAPE to
the south of the boundary on recent SPC RAP mesoanalysis. PW values
of 1.9-2.0 inches are noted across the area along and south of the
boundary.

Cu development across central KY and southern IN has been modest so
far. However, expect scattered convective initiation over the next 1-
2 hours. Scattered strong storms are still expected this afternoon
and evening. Strong instability, weak shear, and a very moist
airmass all point to the usual summer storm hazards: torrential
rainfall, localized wet microbursts, and frequent lightning. Strong
storms look a little more likely across portions of southern IN and
north-central KY, closer to the boundary. And with somewhat lower 1-
hr FFG (1.5 in or less) in parts of Jefferson, Bullitt, and Nelson
counties, decided to expand the Flood Watch westward slightly. The
Flood Watch still runs through Midnight EDT tonight.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 711 AM EDT Thu Jul 17 2025

Earlier convection has diminished across the region.  In the wake of
the evening convection, skies were clear to partly cloudy across the
region with temperatures in the low-mid 70s.  Winds remain light
across the region which will likely limit overall fog formation with
the exception of the protected valleys.  Through sunrise, no
significant weather is expected with temperatures remaining in the
low-mid 70s.

For today, a rather active day of weather is expected.  A weak
surface cold front will drop into the I-70 corridor this morning and
it probably will not make it much further south during the day.  To
the south of this boundary, a rather convergent low-level flow will
draw ample moisture into the region with surface dewpoints remaining
in the low-mid 70s.  With insolation during the morning, we'll see
ample instability develop with scattered showers and storms expected
to fire by late morning.  A gradual upscale growth into multiple
clusters is expected.  While instability will be fairly high across
the region (3500-4500 J/kg), deep layer shear continues to look less
than 20kts.  Very warm cloud depths are expected once again, so
water loaded downdrafts producing strong gusty winds and intense CG
lightning will be the main severe threats.  With PWATs remaining in
the 2.1-2.2 inch rain, torrential rainfall is expected with these
storms.  The good news is that the environmental flow will keep
storms moving, however, storms may have a tendency to train across
portions of the region and that could produce some flooding issues.

Looking at the last few days of rainfall across the state, most
areas have seen rainfall, but there have been a few corridors where
locally heavier rainfall has been observed.  Tonight's datasets
continue to suggest heavier rainfall across SE Indiana and down into
the Bluegrass region.  This area has seen some good rainfall in the
last 24-36 hours.  After coordinating with surrounding offices,
we're going to hoist a Flood Watch across our NE sections with
ILN/JKL for this afternoon/eve activity.  This area is where we
currently thing that flash flooding may be most concentrated.

Outside of the rainfall/storm threat, it will be a rather hot/humid
data across the area with highs in the upper 80s/lower 90s.  Those
temps combined with dewpoints in the low-mid 70s will likely produce
heat indices in the upper 90s to the lower 100s.  Confidence here
for meeting criteria is low because it is possible that convective
coverage may foil our afternoon heating and potentially limit
heating in some areas.

For Tonight, ongoing convection should be in progress this evening
across the area.  Convection should diminish after sunset with the
loss of heating.  With the front remaining north of the region,
overnight lows will only drop into the lower-middle 70s.  With the
expectation of convection diminishing around midnight, we'll let the
flood watch go until then.  However, there is some signaling in the
guidance that additional shower/storms may develop later in the
night.  Should that occur, an extension of the flood watch may be
required in subsequent forecasts.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 711 AM EDT Thu Jul 17 2025

Remnant frontal boundary will remain just north of the region on
Friday and a tropical airmass will remain in place across the
region.  Given anticipated convective coverage Thu/Thu night,
lingering convective cloud debris will likely be noted across the
region on Friday keeping high temperatures in the upper 80s to near
90.  Shear across the region will remain rather weak, but we'll see
the typical diurnal increase in instability across the region which
should support at least scattered convection once again.  Mainly
pulse-type storms are expected with waterloaded downdrafts, though
overall coverage may be a bit more limited on Friday with less
instability and lack of focused forcing.  Heavy rainfall with storms
will be possible as PWATs remain at/above 2 inches.  Lows Friday
night will drop back into the low-mid 70s.

For the weekend and into next week, the upper level pattern is not
expected to change much.  The SE ridge looks to remain entrenched
across the area with perhaps a slight retrogression to the west.
Slight ridging may take place across the Plains which will result in
a more northwest flow regime across the Ohio Valley.  Multiple
perturbations moving through within the flow pattern will likely
produce episodic bouts of convection.  Model soundings through the
period continue to show rather weak shear, but ample diurnal
instability developing.  With a tropical airmass remaining in place,
heavy rainfall with storms will remain a threat.  The northwest flow
pattern could result in multiple MCSs that could drop down into the
region.  Current thinking is that northern IL/central IN and down
into northeast/eastern KY could see the most convective action here
along with a threat of flash flooding.

Outside of storms, it will remain hot and muggy with daytime highs
in the upper 80s to around 90 and overnight lows in the low-mid 70s.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 219 PM EDT Thu Jul 17 2025

Scattered to numerous showers and storms are expected through the
evening hours, especially in southern IN and north-central KY near a
stalled frontal boundary. TSRA coverage/probability is highest at
HNB/SDF/LEX, with lower chances at BWG. There is also a concern for
isolated to scattered lingering overnight as a weak mid-level wave
moves west to east over the stalled boundary. A very moist airmass
will yield high rainfall rates with any storm. Localized
downbursts/gusty winds are also possible with stronger storms this
afternoon and evening.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Flood Watch until midnight EDT tonight for KYZ029>043-045>049-
     055>057-067.
IN...Flood Watch until midnight EDT tonight for INZ078-079-091-092.

&&

UPDATE...EBW
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...EBW

Hazardous Weather Outlook
National Weather Service Louisville KY
1202 PM EDT Thu Jul 17 2025

INZ078-079-091-092-KYZ029>043-045>049-055>057-067-181615-
Scott IN-Jefferson IN-Floyd-Clark IN-Bullitt-Jefferson-Oldham-
Trimble-Henry-Shelby-Franklin-Scott KY-Harrison KY-Spencer-Anderson-
Woodford-Fayette-Bourbon-Nicholas-Nelson-Washington KY-Mercer-
Jessamine-Clark KY-Boyle-Garrard-Madison-Lincoln-
1202 PM EDT Thu Jul 17 2025

...FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...

This Hazardous Weather Outlook is for portions of southern Indiana
and central Kentucky.

.DAY ONE...This afternoon and tonight.

Scattered to numerous showers and thunderstorms are expected across
the outlook area this afternoon and evening. Some of the storms could
be severe with strong gusty winds, torrential rainfall, and intense
lightning. The heavy rainfall expected with these storms could lead
to instances of flash flooding across southern Indiana and north
central Kentucky.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Rounds of showers and thunderstorms are expected through the
upcoming period. Thunderstorms will be capable of producing
torrential rainfall, gusty winds, and lightning. Heavy rainfall rates
may lead to localized flash flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed.

GENERAL STORM MOTION OF THE DAY:

Storms will move to the E or ENE at 15 to 20 mph.

Any users of this storm motion must be aware that thunderstorm activity
can be erratic and constantly evolving.  Please use this with caution
and be prepared for changing conditions.

&&

More information, along with other weather, hydrological and
climate information can be found, at weather.gov/louisville.

INZ076-077-083-084-089-090-KYZ023>028-053-054-061>066-070>078-081-
082-181615-
Orange-Washington IN-Dubois-Crawford-Perry-Harrison IN-Hancock-
Breckinridge-Meade-Ohio-Grayson-Hardin-Larue-Marion-Butler-Edmonson-
Hart-Green-Taylor-Casey-Logan-Warren-Simpson-Allen-Barren-Monroe-
Metcalfe-Adair-Russell-Cumberland-Clinton-
1202 PM EDT Thu Jul 17 2025 /1102 AM CDT Thu Jul 17 2025/

This Hazardous Weather Outlook is for portions of southern Indiana
and central Kentucky.

.DAY ONE...This afternoon and tonight.

Scattered to numerous showers and thunderstorms are expected across
the outlook area this afternoon and evening. Some of the storms could
be severe with strong gusty winds, torrential rainfall, and intense
lightning.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Rounds of showers and thunderstorms are expected through the upcoming
period. Thunderstorms will be capable of producing torrential
rainfall, gusty winds, and lightning. Heavy rainfall rates may lead
to localized flash flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed.

GENERAL STORM MOTION OF THE DAY:

Storms will move to the E or ENE at 15 to 20 mph.

Any users of this storm motion must be aware that thunderstorm activity
can be erratic and constantly evolving.  Please use this with caution
and be prepared for changing conditions.

&&

More information, along with other weather, hydrological and
climate information can be found, at weather.gov/louisville.

EBW

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special Weather Statement
National Weather Service Louisville KY
308 PM EDT Thu Jul 17 2025

INZ083-089-171945-
Perry IN-Dubois IN-
308 PM EDT Thu Jul 17 2025

...STRONG THUNDERSTORMS WILL IMPACT SOUTHERN DUBOIS AND NORTHWESTERN
PERRY COUNTIES THROUGH 345 PM EDT/245 PM CDT/...

At 307 PM EDT/207 PM CDT/, Doppler radar was tracking a cluster of
strong thunderstorms near Dale, moving northeast at 15 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Jasper, Huntingburg, Ferdinand, Holland, Saint Marks, Sassafras,
Bretzville, Duff, Adyeville, and Huntingburg Airport.

Those attending the Dubois County 4H Fair are in the path of this
storm and should prepare for IMMINENT DANGEROUS WEATHER CONDITIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3832 8707 3844 8683 3820 8663 3816 8680
      3818 8680 3818 8679 3821 8679 3820 8707
TIME...MOT...LOC 1907Z 246DEG 11KT 3819 8708

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Padgett