Shepherdsville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

178
FXUS63 KLMK 160807
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
407 AM EDT Fri May 16 2025

.KEY MESSAGES...

*  SIGNIFICANT SEVERE WEATHER OUTBREAK POSSIBLE LATE THIS AFTERNOON
   INTO THIS EVENING.

*  All severe weather hazards are on the table, including damaging
   winds, large hail, tornadoes, and torrential rainfall. A few
   strong tornadoes and instances of very large hail are possible.

*  Strong to severe thunderstorms are also possible this morning
   west of Interstate 65, with large hail as the main hazard.

&&

.MESOSCALE...
Issued at 336 AM EDT Fri May 16 2025

Boundary has lit up from the Shawnee National Forest in southern
Illinois ENE to near Henderson, and storms tapped into strong
elevated instability to produce vigorous cores aloft. Given the very
unstable and strongly sheared environment, as storms continue to
develop through early morning they will carry mainly a SVR hail
threat from the Pennyrile into the Hoosier National Forest and
sections of Kentucky west of Interstate 65. Damaging winds and even
a tornado or two can`t be ruled out completely, but storms will have
a really difficult time becoming sfc based. Confidence is also
slightly diminished south of the WK Parkway but we could see
convection down toward BWG later in the morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 407 AM EDT Fri May 16 2025

A significant severe weather outbreak is possible later this
afternoon and this evening across the Ohio Valley. Storms developing
ahead of an incoming cold front will quickly become severe in a very
unstable and strongly sheared environment. All severe weather
hazards, including widespread damaging winds, very large hail, and
strong tornadoes are possible, as well as localized flash flooding.

Main bust potential hinges on the evolution of storms this morning,
which have developed over western Kentucky. These storms will have a
large hail threat of their own, especially west of Interstate 65.
While they will at least temporarily stabilize the atmosphere,
strong warm advection is likely to win out, allowing a fairly quick
recovery this afternoon.

With around 3000 J/kg of mixed-layer CAPE, 1000 J/kg of downdraft
CAPE, and 60 kt of effective shear, initially discrete storms will
organize into at least bowing segments. A few of the discrete cells
could produce very large hail and/or strong tornadoes, and line
segments could produce hurricane-force wind gusts. Spin-up tornadoes
will also be in play with any of the bowing structures as well.

The peak severe threat could be slightly delayed depending on how
quickly the atmosphere can reload after morning convection, but the
threat will mainly be focused on the evening hours. Initial discrete
cells could develop in the late afternoon.

It`s also worth noting that in the late evening, the line will
become more east-west oriented, opening the door for excessive
rainfall especially over south-central Kentucky. Confidence in the
exact placement is low at this time, but it bears watching as the
event unfolds.

Bottom line, significant severe weather is possible late this
afternoon and this evening. Make sure you have multiple ways to
receive warnings and a plan in place should a warning be issued!

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 352 PM EDT Thu May 15 2025

By Saturday morning, the actual cold front will be pushing through
the area with most of the showers and storms exiting to our east.
The associated upper low will be over the Great Lakes with the
longwave trough axis extending south over the OH and TN Valleys
before flattening out against the subtropical ridge over the Gulf.
Weak CAA behind the front will result in climatological normal
temperatures for the weekend with highs in the mid to upper 70s to
lower 80s accompanied by breezy WSW winds on Saturday. Overall, most
will experience a fair weather weekend.

Southern KY will see a slight chance of showers on Sunday as the
southern edge of the new airmass begins to lift northward due to the
next low pressure system strengthening over the Central Plains. This
will begin another period of unsettled weather as we enter the
beginning of the new work week.

By Monday, a warm front will begin lifting across the region
resulting in warm and moist air advection, as PWATs surge into the
upper percentiles of SPC`s sounding climatology. Models tend to
agree on convection from our west moving into our area by Monday
morning with another round Monday evening. The warm front appears to
stall over the region, prolonging our shower and storm chances into
Tuesday and Wednesday before the occluded low pushes through on
Wednesday. With model soundings advertising sufficient instability
and ML guidance also showing enhanced severe probabilities, severe
weather can not be ruled out. Details remain hazy this far out, but
will continue to monitor closely with subsequent forecast packages.
Stay tuned.

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 137 AM EDT Fri May 16 2025

Main challenge in this TAF set is timing and impacts of two
different potential waves of convection.  Low-confidence forecast
overnight as hi-res models show new development after ~08Z.
Consensus timing on a morning wave would be starting 10-12Z for the
terminals but could easily be focused just in the north on SDF and
LEX or just south in BWG. Will carry a period of SHRA for now
without any significant restrictions in cig/vis.

Gusty SSW winds through the afternoon, and then another wave of
storms comes in starting around 00Z, mainly for SDF and LEX. Handled
those with TEMPO for IFR vis and gusty winds in the stronger storms.
The evening storms could produce significant severe wind gusts, but
this will be modulated by the behavior of morning storms, so will
not hit that too hard just yet.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

MESOSCALE...RAS
SHORT TERM...RAS
LONG TERM...CG
AVIATION...RAS