881
FXUS63 KLMK 140048
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
848 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.

&&

.UPDATE...
Issued at 848 PM EDT Thu Jun 13 2024

It`s another nice evening across the region as high pressure
continues to dominate the forecast. The overall forecast remains in
a good shape, and no changes are planned at this time. Have been
watching convection fire up along the cold front currently
stretching across Illinois and Indiana, and we will see high level
cloud debris begin to stream overhead later this evening. As the
front continues to slide south overnight, expect to see precip
activity mostly dissipate as it approaches the Ohio Valley. Will
keep the low PoP chance across southern Indiana for the morning, but
otherwise watch for redevelopment tomorrow afternoon along the
front.

&&

.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 /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 744 PM EDT Thu Jun 13 2024

VFR flight conditions this evening will continue throughout the
forecast period. With showers and thunderstorms developing along the
cold front to our north, we expect high level cloud debris to begin
streaming over our region overnight. This cold front and the
associated precip will drive southward towards the Ohio River by
tomorrow morning, and a few light showers may be possible at HNB and
SDF. However, these showers will be dissipating as they approach, so
no impacts are expected at the terminals. The cold front will
continue to pass through the region tomorrow, resulting in a wind
shift from SSW to N wind.

&&

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

&&

$$

UPDATE...CJP
SHORT TERM...CSG
LONG TERM...DM
AVIATION...CJP/LMP