864
FXUS63 KLMK 161753
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
153 PM EDT Fri Aug 16 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Scattered thunderstorms are expected today. Some locally heavy
    rainfall is possible, but the risk for severe weather is low.

*   Unsettled weather is likely Saturday and Sunday with scattered
    showers and thunderstorm being possible each afternoon/evening.
    Strong to severe storms with gusty winds will be possible
    Saturday afternoon and evening.

*   Dry weather is expected for much of next week, with well below
    normal temperatures.

&&

.UPDATE...
Issued at 832 AM EDT Fri Aug 16 2024

The forecast is on track this morning. A 30+ kt SW LLJ is streaming
across the CWA, providing healthy moisture transport and low-level
ascent. Scattered thunderstorms are ongoing in central KY and
southern IN, with more widespread coverage across southern IN. A
Flood Advisory is in effect for northern Orange and Washington
counties, where we`ve had some training convection this morning.
Minor flooding will be possible throughout the morning from north of
Paoli east through the Campbellsburg and Georgetown, IN areas
(especially in typically flood-prone locations such as low water
crossings).

These storms will also cause some ponding on the roads this morning,
increasing the risk for hydroplaning. Slow down in storms and
heavier rainfall with the decreased traction and lower visibility.
Shower and storm coverage is still expected to decrease from west to
east late this morning through midday as the low-level jet weakens.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 337 AM EDT Fri Aug 16 2024

A stacked low, embedded in an upper trough, continues to work its
way through the Midwest on it way towards the Great Lakes. It is
expected to make it to the Lake Michigan/Michigan area by Saturday
morning. As the system moves along this path, multiple weak
shortwaves will work through the Lower Ohio Valley, helping to
initiate convection across the region, but with instability and deep
layer shear continuing to be marginal, severe weather isn`t expected.

Precipitable water values will range between 1.7" to over 2" over
the CWA as the system`s surface low puts pressure on a surface high
centered over the Carolinas. This will drive gusty (20-25 mph)
southwest winds over southern Indiana and central Kentucky as it
continues to funnel Gulf of Mexico moisture into the area, but later
this evening as the system slides eastward, drier west to northwest
flow over the CWA will cause precipitable water values to begin
falling below 1.5", leading to a mostly dry night over the CWA.

This morning, we are expecting an increase in showers and
thunderstorms across southern Indiana and central Kentucky as we
head through the morning hours. With precipitable water values
fairly high, we could see some heavy rain rates which could cause
some ponding of water in low areas and on area roadways, but given
the progressive nature of the convection, not expecting widespread
flooding.

This afternoon, showers and thunderstorms are expected to become
more isolated and scattered and not so widespread as sunshine
becomes more likely later in the afternoon and evening hours. High
temperatures will climb back into the 80s.

Early tonight, any remaining showers are expected to fade quickly as
the night remains mostly dry. Easing southwest winds with partly
cloudy skies will keep low temperatures in the upper 60s to low 70s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 337 AM EDT Fri Aug 16 2024

A cold front to our northwest at 12Z Saturday will advance to the
Ohio River by evening and into Kentucky Saturday night. Upstairs a
5H low will be spinning over Michigan with small ripples circulating
around it. These features will interact with with a moist and
unstable atmosphere to produce showers and storms. The best chance
for strong to severe storms will come late Saturday afternoon into
the evening hours with CAPE around 1500 J/kg, bulk shear around
30kt, and precipitable water values of 1.5-2". High freezing heights
and weak low level SRH suggest gusty winds, small hail, and locally
heavy downpours will be the main threats. This is in agreement with
the CSU-MLP hazards outlook and the SPC Day 2.

Sunday and Sunday night the upper low over Michigan will open up
into a trough as it pushes east into the northern Appalachians,
while the Saturday cold front likely settles just off to our south
and east. While scattered showers and garden variety thunderstorms
may develop around peak heating, severe storms are not expected.

A meridional upper pattern will dominate the Monday - Thursday time
period with a strong upper ridge reaching from the Prairie Provinces
through the Great Plains to northern Mexico, bookended by upper
troughs over the Pacific Northwest and southeast Canada. At the
surface high pressure will slowly advance from Ontario through the
Great Lakes to the mid Atlantic Coast. Other than perhaps a few
lingering showers and storms along and east of US 127 on Monday,
this will result in dry weather for southern Indiana and central
Kentucky. Temperatures Monday and Tuesday will be several degrees
below normal. Dew points Tuesday afternoon may briefly touch the
upper 40s in the Blue Grass, with lower 50s elsewhere, under sunny
skies and temperatures peaking around 80.

Temperatures will moderate a few degrees Wednesday and Thursday as
we get into some return flow behind the East Coast high.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 152 PM EDT Fri Aug 16 2024

Isolated to widely scattered showers and storms are possible into
this evening. However, coverage should be pretty limited due to
weaker forcing. Therefore, have opted not to include any TSRA
mention in the first 6 hours. However, confidence is higher in
scattered to numerous showers and storms Saturday afternoon and
evening. Some strong to severe storms will be possible and could
bring brief TSRA impacts, including very heavy rainfall, lower
ceilings/vsbys, gusty winds, and lightning.

Southwesterly winds will remain breezy through sunset with gusts up
to around 20 kt. Light SW winds expected overnight with mainly dry
conditions. Showers and storms should begin to develop over portions
of southern IN and central KY around 17-19Z Sat ahead of a cold
front. Southwesterly winds will again increase during the daytime
before veering westerly Saturday evening and overnight.

&&

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

&&

$$

UPDATE...EBW
SHORT TERM...KDW
LONG TERM...13
AVIATION...EBW