653
FXUS63 KLMK 151754
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
154 PM EDT Thu Aug 15 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Stormy weather returns this week, with the highest chance for
    showers and thunderstorms being Thursday night and Friday.
    Isolated strong or severe storms could be possible Friday
    afternoon.

&&

.UPDATE...
Issued at 1003 AM EDT Thu Aug 15 2024

Skies are partly cloudy this morning with temperatures warming into
the low to mid 70s. A band of convection continues to push east
across central and southern IL, but these storms will weaken as they
move into a more stable environment over IN. A notable west-to-east
moisture gradient is in place across the Lower Ohio Valley, with the
main LLJ/moisture transport axis still confined to our west across
MO and IL. A few showers may linger into our southern IN counties,
mainly west of I-65 this afternoon, but confidence in thunder is
low. Otherwise, most will enjoy a dry day with afternoon temps
warming through the 80s.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 358 AM EDT Thu Aug 15 2024

Today will begin uneventful under mostly clear skies with calm
to light and variable winds. This is in thanks to an upper ridge
sliding over the region and surface high pressure, centered over
Pennsylvania, influencing the Ohio Valley, but just behind the upper
ridge, an upper trough is pushing a line of convection through Iowa
and Missouri. This line is continuing to weaken, but it could hold
together long enough to make it into western Indiana and western
Kentucky. This could provide for a few sprinkles this afternoon if
it can survive, but not expecting thunderstorms or anything much
more than a few drops as model soundings show there isn`t much in
the way of instability and a dry layer near the surface. We can
expect to see increasing cirrus and some mid level clouds as we head
into the afternoon hours. The mostly dry, mostly sunny day will lift
temperatures into the upper 80s with the possibility of a few places
reaching 90.

Tonight, as we sit in the warm sector behind the warm front and
ahead of an approaching cold front, that`s embedded in the upper
trough, southern winds will continue to funnel Gulf of Mexico
moisture into the Lower Ohio Valley. Dew points in the low 70s will
continue working into the CWA from the southwest as precipitable
water values approach 2". This will increase shower and thunderstorm
chances throughout the night as  they become more widespread during
the second half of the night. Severe weather isn`t expected as model
guidance shows limited instability and stable near surface layer.
Added sky cover and warm air advection is expected to keep lows in
the upper 60s to low 70s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 358 AM EDT Thu Aug 15 2024

Friday morning still appears to be the most likely time for heavy
and widespread precipitation to move across the region as an axis of
2" PWATs moves through the area. Model guidance continues to show
limited instability and shear with high LCLs, so severe weather
isn`t expected. The best chance for anything stronger or severe
would be Friday afternoon, but also believe the chances of this are
less than they were yesterday as cloud cover will likely limit
instability recovery. There remains some uncertainty on timing with
additional shower and thunderstorm chances into the weekend. With
the cold front expected to move through the region on Saturday,
additional rainfall is expected, but wouldn`t count on the whole
weekend being a washout as this is summer convection, more scattered
in nature. Behind the front, precipitation chances will begin to
diminish.

High temperatures on Friday are expected to reach into the upper 80s
to low 90s before the cold front passes on Saturday, limiting highs
on Sunday to the low to mid 80s. These cooler temperatures will last
into the middle of next week.

From Sunday through the end of the work week, a large upper ridge
and surface high pressure will bring a return of dry mostly sunny
skies to the Lower Ohio Valley. After the surface high passes east
of the region late in the week, slightly warmer temperatures can be
expected from southern surface flow.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 153 PM EDT Thu Aug 15 2024

VFR to begin this TAF period with just some SCT mid and high cloud.
A relatively light (< 10 kt) southerly wind will continue this
afternoon into tonight. A low pressure system will continue to move
east over the Upper Midwest during this TAF period, and deeper
moisture and stronger low-level forcing will result in increasing
shower and thunderstorm chances overnight and Friday morning.
Detailed timing for TSRA is difficult to pin down, as activity could
be somewhat scattered in nature overnight. However, HNB and BWG will
have slightly higher TSRA chances 00-06Z Fri with storm chances
spreading eastward Friday morning.

&&

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

&&

$$

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