112
FXUS63 KLMK 200545
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
145 AM EDT Sat Jul 20 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Gradual warm up this weekend with increasing mugginess by early
    next week.

*   Shower and storm chances increase across southern KY this
    weekend, then everywhere else by next week.

*   Locally heavy rainfall possible with any of these showers and
    storms.

&&

.UPDATE...
Issued at 957 PM EDT Fri Jul 19 2024

Areas east of I-65 are seeing high clouds overhead this evening.
Areas west of I-65 will remain mostly clear through the overnight
hours. With some clearing and calm to light winds, patchy fog
development is possible in the early morning hours. Otherwise, weak
troughing will swing through the region bringing weak forcing. Weak
forcing coupled with moisture return over southern Kentucky will
allow for isolated to scattered showers and storms to develop.
Temperatures are expected to reach the mid to upper 80s in the
afternoon, feeling muggy to the south with dew points in the upper
60s and low 70s and comfortable to the north with dew points in the
low to mid 60s.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 303 PM EDT Fri Jul 19 2024

Broad area of sfc high pressure over the Ohio Valley and Lower Great
Lakes will be the dominant weather feature tonight into tomorrow
with predominantly dry weather for most of our CWA. A positive
tilted trough aloft stretching from the Hudson Bay towards Louisiana
along with an Upper Ridge Axis centered over Bermuda in the Atlantic
will allow for Gulf of Mexico moisture to increase over the region
for the weekend. A weak impulse coming out of the Deep South will
move northeast through the TN Valley tonight into tomorrow while sfc
reflection will move along the same path along a stalled sfc
boundary helping to increase clouds and shower/storm chances during
the day tomorrow.

High clouds will increase overnight from the south as winds become
light and variable. Dew point values will be a little higher than
last night along with our temperatures tonight. Lows in the low/mid
60s are expected with a few upper 50s across southern IN. Depending
on cloud cover, there could be some very isolated fog development,
mostly along the KY/TN borders where we`ve seen the most rain from
the last couple of days.

Thanks to the aforementioned sfc high over the region, fair dry
weather is expected but as the weak sfc low works along the stalled
boundary to our south, an inverted sfc trough will nose northward
into south-central KY. This will help to increase shower/storm
chances in the afternoon for locations along to south of the
Parkways. I anticipate most of the activity to be limited and
isolated to scattered in nature given the general lack of lift.
Skies will be partly to mostly sunny and afternoon highs in the mid
to upper 80s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 303 PM EDT Fri Jul 19 2024

An active weather pattern is on tap late weekend into the next week
with chances for precipitation each day.  A general stagnant upper
level trough of low pressure will hang across the area.  With
limited jet energy Sunday and Monday and few forecast vort maximums,
not expecting much in the way of strong organized thunderstorms.
However, model forecast soundings do have decent depictions of
instability that increases with locations closer to the KY/TN
border.  Plenty of moisture in the atmosphere could lead to heavy
rain producers and perhaps some areas of small hail and locally
gusty winds in thunderstorms.

Tuesday and beyond, more moisture with PWs at 2+ inches advect
across areas of stagnant vort maximums southeast of a line from
Bowling Green to Campbellsville to Lexington.  In these areas there
is increasing confidence for thunderstorm training and higher
chances for efficient heavy rain producing storms.  Model forecast
soundings show meager instability and lack of shearing winds,
however the pattern is conducive for efficient rain producers.
Flooding is possible depending on rain rates and the location of
storm tracks. Current forecast has upwards of 1.5-2 inches of rain
accumulations from repeated rounds of rain through the end of next
week, although higher amounts of rain are almost entirely possible
in heavier rain producer thunderstorms.

Outside of Sunday`s high temperatures being close to normal in the
mid to upper 80s, max temperatures will gradually lessen to the low
to mid 80s toward the end of the week.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 145 AM EDT Sat Jul 20 2024

Through the current forecast period, low-level moisture will
increase from south to north as a weak disturbance passes through
the region later today. Current observations show 6-7 kft ceilings
across much of Tennessee and into BWG at this hour. These clouds
should work their way toward SDF/LEX/RGA over the next few hours,
with SCT-BKN 5-7 kft clouds continuing through much of the day.
Winds are expected to be fairly light through the period, with a
weak pressure gradient causing low confidence in prevailing wind
direction. Later today, isolated showers and thunderstorms are
expected to develop near BWG. While a few of these cells will move
toward LEX/RGA, confidence is too low to include in the forecast at
this time. After sunset this evening, VFR conditions should continue
with rain showers expected to diminish.

&&

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

&&

$$

UPDATE...SRM
SHORT TERM...BTN
LONG TERM...MCK
AVIATION...CSG