058
FXUS63 KLMK 131024
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
624 AM EDT Sat Jul 13 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Mostly dry weather and warming temperatures expected for for the
    weekend.

*   Triple-digit heat index values could return Sunday afternoon and
    are likely early next week.

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

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 310 AM EDT Sat Jul 13 2024

RAP upper level analysis and water vapor imagery this morning showed
a disturbance over IL with plenty of moisture streaming into the
Ohio Valley. Light and variable winds were present under clear skies
with some fog developing across the area. Temperatures ranged from
the low to mid 70s.

Weak wind flow through the atmospheric column today with not much of
a jet stream, but the small disturbance ripple aloft moving across
the Ohio River Valley could provide just enough lift to create some
showers and thunderstorms this morning into the early afternoon,
especially west of I-65 (low confidence in development). Model
soundings have a decent CAPE instability profile (2000+J/KG at
times) across the area, but effective inflow and 0-6 KM shear
numbers are fairly week. Any storms that develop (if they develop)
could result in brief heavy downpours of rain with the moisture
availability, along with small hail and gusty winds in any
storm that develops.

Weak shortwave trough base passes through the area by the early
afternoon with steady (albeit weak) mid level height rises through
the day as high pressure becomes the dominate weather feature with
slightly warmer highs than Friday in the low to mid 90s with heat
indices between 95 and 100 degrees. Light winds heading into
Saturday night could result in some patchy fog in areas, especially
early to mid night. Winds are expected to increase slightly that may
mix out fog into the later night with lows in the upper 60s to lower
70s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 310 AM EDT Sat Jul 13 2024

The Ohio Valley will remain under the influence of a broad upper-
level ridge stretching from the Four Corners/Intermountain West
eastward towards the southeast US and Bahamas Sunday into the start
of the week. Weak northwest to quasi-zonal flow over the region and
weak southwesterly flow at the sfc will result in continued hot and
humid weather. Daily highs for Sunday though Tuesday will range from
the mid/upper 90s and with dew points in the upper 60s/low 70s heat
index values will range between 100-105F. There will be little
relief each night from the heat as lows dropping into the low 70s
and urban locations in the mid 70s. Along with the heat, the weather
is mainly dry. While we can`t rule out an isolated shower/storm
Sunday due to a weak system passing by to our north clipping parts
of far southeast IN and the Bluegrass, the next chance of
showers/storms will be Tuesday afternoon ahead of an approaching
cold front working in from the Great Lakes.

Best chance for showers/storms will be Wednesday as the sfc boundary
will work across the region. Moisture pooling ahead of the front
with result in PWAT values near 2.00" supporting storms that could
produce heavy rainfall. As for the severe threat, while we will have
instability, shear remains low for any organized updrafts and
convection. Gusty winds can`t be ruled out but for now confidence is
low.

Front will push south by Thursday but could potentially get hung up
across the KY/TN borders so could still see a few lingers
showers/storms across the south. Temperatures will be cooler for the
end of the week into the mid/low 80s before rebounding to the
mid/upper 80s to start the weekend.

&&

.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 622 AM EDT Sat Jul 13 2024

Patchy MVFR morning fog for terminals in south central Indiana and
other low lying valleys will dissipate by mid morning. A disturbance
moving across the Ohio River Valley over the next 6 hours could
bring an isolated thunderstorm in the vicinity of area terminals,
but confidence is low as to direct impact to area runways.  Gradual
clearing to VFR higher level clouds this afternoon into the evening
with winds shifting from the west to the south.  Patchy MVFR fog and
mist possible to return tonight into Sunday morning.

&&

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

&&

$$

SHORT TERM...MCK
LONG TERM...BTN
AVIATION...MCK