267
FXUS63 KLMK 141740
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
140 PM EDT Sun Jul 14 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Triple-digit heat index values could return this afternoon
    through Tuesday.

*   Chance of showers and storms along and north of I-64 later this
    afternoon/evening with gusty winds, heavy rain.

*   Shower and storm chances look to increase by the middle of this
    week as a frontal boundary sinks into the area.

*   Cooler temps in the 80s for Thursday into Saturday.

&&

.UPDATE...
Issued at 1055 AM EDT Sun Jul 14 2024

The current forecast is on track, and only minor tweaks were made in
the late-morning update. Watching a MCS over northern Indiana this
morning, which will be taking a dive to the southeast in the coming
hours. It`s possible the southern periphery of this complex could
come close to our far northeastern forecast area later today, but
the latest trends are suggesting this complex may stay just to our
northeast along the instability gradient. Because of this, have
trimmed PoPs slightly to shift them more northeast, but have also
kept PoPs less than 30%. Forecast temps are also on track, with no
changes made. We`ll see temps climb into the 90s, with heat indices
around 100F. Any afternoon convection and cloud debris could result
in localized temperature drops, but on a broad scale the SPS still
looks good. Updated forecast package will be sent.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 305 AM EDT Sun Jul 14 2024

The main focus for today will be the increased heat and humidity in
the afternoon across our CWA. Highs will range from the low/mid 90s
with dew points in the low 70s/upper 60s. This will yield max heat
index values at or just above 100 degrees but below the heat
advisory category of 105. Will continue the Special Weather
Statement for the hot and humid conditions. There is a potential to
bust forecast temperatures due to cloud cover associated with
convective debris as well as any development of showers/storms in
the late afternoon & evening. A series of MCS working across
northern IN/southern MI and a second one across WI/MN will push
southeast along the peripheral of the upper ridge associated with a
weak shortwave embedded in the weak northwest flow. While confidence
remains relatively low, given the over achieving convection the last
couple of days and the above mentioned lift from outflow
boundaries/embedded shortwave, decided to carry a 20-30% PoP along
and north of I-64 later this afternoon into the evening. While any
activity will provide relief from the heat, they could also have
gusty winds, heavy rain and lightning. This seems to be in line with
the SPC Day 1 Convective outlook which brings the marginal risk (1
out of 5) to just outside of our CWA across southeast IN/southern
OH.

Forecast for this evening will be dependent on when and where
convection develops in the afternoon. Some of the hi-res models like
the NAM 3km want to bring a line of storms into northern KY/southern
IN this evening. While this appear to be an outlier based on other
CAMs, it should be monitored none the less. Otherwise, skies should
clear with warm and muggy conditions with lows near 70.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 305 AM EDT Sun Jul 14 2024

Monday - Tuesday

High pressure will dominate the local weather patttern as
temperatures will be well above normal for Monday and Tuesday. Highs
each day will be in the mid to upper 90s (between 5 and 10 degrees
above normal) with head indices between 100 and 105.  While below
thresholds for heat headlines, sensitive groups and those working
outdoors may experience heat related symptoms.  Ensuring rest breaks
and limiting exposure outside during the peak afternoon heating
hours will help limit heat illness risk.

Dry weather is expected Monday, but Tuesday afternoon into the
evening an approaching cold front will bring chances for showers and
thunderstorms across the area.  Storms will start isolated on
Tuesday afternoon and increasing in coverage into the evening and
overnight along the passing front.

Wednesday - Sunday

An upper low well north of the Great Lakes and associated surface
cold front across the Ohio Valley will bring enough forcing and
moisture convergence to develop showers and storms for the mid-late
week. While the better jet dynamics will remain to the north of the
forecast area, a few strong storms could develop with heavy
downpours of rain, frequent lightning, wind gusts and hail.

While chances for precipitation may linger after the front passes
each day through the weekend (especially south toward Lake
Cumberland region), a nice temperature drop is expected Thursday and
into the weekend. Highs in the low to mid 80s are near to slightly
below normal for mid July, while high temperatures creep up to near
normal across the state for the weekend in the upper 80s.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 139 PM EDT Sun Jul 14 2024

Fair weather SCT cu field is developing as we get into peak heating
of the day, but VFR conditions will continue for this forecast
period. Winds will remain a southwesterly flow today, becoming more
relaxed by this evening. Sct clouds will mostly dissipate by sunset
as daytime heating is lost.

A cluster of thunderstorms across central Indiana is moving to the
E/SE, and should remain far enough away from any terminals to cause
impacts. Will continue to watch for some isolated storms this
afternoon for the I-64 corridor, but not confident enough to include
any mention in the TAF at this time. VFR conditions continue
tonight, but another round of thunderstorms diving southward from
Chicago looks to run out of steam before getting to the Ohio River
by tomorrow morning. Will need to watch these trends too, but have
kept TAFs dry for tomorrow as well.

&&

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

&&

$$

UPDATE...CJP
SHORT TERM...BTN
LONG TERM...MCK
AVIATION...CJP