310
FXUS63 KLMK 131929
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
329 PM EDT Thu Jun 13 2024

.KEY MESSAGES...

*   Isolated showers and thunderstorms possible late tonight and
    again tomorrow afternoon.

*   Above normal temperatures expected Sunday into next week. Spotty
    showers and storms possible next week as well, though confidence
    in their development remains low.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 328 PM EDT Thu Jun 13 2024

Across the region this afternoon, it is a seasonably warm day with
temperatures in the mid-to-upper 80s at this hour. Latest visible
satellite imagery gives a clue to where there is somewhat higher
boundary layer moisture, as a scattered cumulus field has developed
south and east of a line from Bowling Green to Lexington. Still, the
air mass overhead is somewhat dry for mid June, with dewpoint
readings generally in the upper 50s and low-to-mid 60s at this hour.
Latest surface analysis shows a ridge of high pressure extending
from the ArkLaTex east-northeast through the Tennessee valley and
off the Carolina coast. To the north and west, an area of low
pressure associated with a cold front extends from a sfc low center
over northern Ontario down into the Great Lakes region and
eventually into the central Plains. Over the next 24 to 36 hours,
this front will descend toward and move through central KY and
southern IN, providing our first chances for precipitation in quite
a while.

This evening into tonight, clouds will increase, especially after
midnight as cirrus from storms well to our north and west moves over
the region. This area of showers and storms, which will develop over
the next few hours along the I-80 corridor, will weaken as they
encounter a much more stable environment along and south of I-70 in
central Indiana. Still, an area of showers and one or two rumbles of
thunder will approach our southern Indiana communities after
midnight tonight. With model soundings showing dry air below 10 kft,
would expect precipitation to initially struggle to reach the
ground, and rain shower coverage will become much more isolated the
closer it gets to the Ohio River. Winds will go light and variable
tonight, which opens up the possibility for some patchy fog once
again across the deeper southern KY river valleys. Temperatures
should be milder tonight than previous night, with lows only falling
into the 60s.

By sunrise tomorrow, the sfc cold front will be on our doorstep,
with increasing low-level moisture expected in the vicinity of the
front. This should allow for a scattered or broken cumulus field to
develop by tomorrow afternoon, and conditions will be more muggy
tomorrow than in previous days. The potential for showers and
thunderstorms tomorrow afternoon is somewhat limited, as the pool of
greater instability will lie to the west of the area, while the area
of better dynamic support will be to the north and east of the
region as a mid-level shortwave descends from the Great Lakes.
However, with 1000-1500 J/kg SBCAPE present, and enhanced forcing
for ascent along the frontal boundary, will advertise slight chance
to chance PoPs for showers and storms tomorrow afternoon. Most
locations should remain dry, and overall QPF amounts (even in
storms) should generally be less than 0.25". Temperatures tomorrow
afternoon should be relatively similar to today, with expected highs
ranging from the mid 80s to around 90.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 328 PM EDT Thu Jun 13 2024

Slightly cooler and drier air will begin moving into the region
Friday night behind a weak cold front. Surface high pressure over
the Great Lakes will keep a northerly component to winds Friday
night into Saturday. As is typical with June `cold` fronts, we won`t
see much in the way of a temperature reduction behind the front, but
dewpoints should be noticeably lower (compared to Friday) as they
fall into the mid 50s to near 60 by Saturday afternoon.

Much warmer conditions will return to the region as soon as Sunday
as surface high pressure slides into the eastern U.S. and southerly
return flow picks up across our CWA. A very strong upper level ridge
will establish itself across much of the southeastern CONUS, keeping
the above normal temperatures in place. Dewpoints will also steadily
increase Sunday into next week as southerly flow taps into Gulf of
Mexico moisture. Models vary on the `intensity` of the heat and
humidity going into next week, and the current forecast package
takes more of a `middle road` approach. This results in forecast
highs of low to mid 90s starting Sunday and continuing into much of
next week, with heat indices peaking in the mid 90s to around 100
degrees during the afternoon.

Depending on the strength of the upper level ridge and capping in
low/mid levels, we may be able to squeeze out some spotty, diurnally
driven shower/storms during the afternoon and evening hours next
week. This could be an important factor in heat potential next week
as convection/clouds may limit heat indices in some locations.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 134 PM EDT Thu Jun 13 2024

This afternoon and evening, light SW winds are expected to continue
across the region with clear skies as high pressure will remain
centered just to the southeast of the area. Tonight, a cold front
will approach the region from the north, with high clouds from
showers and storms over Indiana and Illinois reaching local
terminals by 02-06Z. Any showers and storms along the front will be
dissipating as they approach the area; however, a few showers could
reach HNB and SDF early Friday morning. Little to no impacts are
expected from these rain showers. Toward the end of the forecast
period, the cold front will pass through the region, with winds
expected to shift from S/SW to NW as the front passes. Additionally,
a BKN 5-7 kft stratus deck is expected to move in behind the front.
Tomorrow afternoon, isolated showers and possibly a storm will try
to develop along the cold front, but confidence is too low in timing
and location to mention in the current forecast.

&&

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

&&

$$

SHORT TERM...CSG
LONG TERM...DM
AVIATION...CSG