933
FXUS63 KLMK 150944
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
544 AM EDT Wed May 15 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Active pattern with many chances of showers and storms through
    Wednesday.

*   The most likely periods for dry weather are Wednesday night
    through Thursday morning and Sunday night through Monday
    morning.

*   The active pattern will continue for the next several days. The
    most likely days for the most widespread showers and storms will
    be Friday-Saturday and possibly Tuesday. The main threat from
    these showers and storms will be locally heavy rain and possible
    flooding, with severe weather a lesser threat.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 324 AM EDT Wed May 15 2024

The stacked low pressure system that has been bringing rounds of
precipitation to southern Indiana and central Kentucky is currently
centered over the northwestern half of the CWA, and before the sun
sets later this evening, it will make it to the Atlantic Coast.
Convective showers and thunderstorms have been scattered in nature.
Some areas, including Orange and Dubois Counties in Indiana, have
received 3 to 4+ inches while farther east, through the Bluegrass
and Lake Cumberland regions, totals have been as low as 0.1-0.2
inches in some places, but as the system moves to the east so will
the totals. With weak deep layer shear and only moderate
instability, we haven`t seen much in the way of severe weather, but
in some areas, mainly around the low, we have seen cells training
towards the center of the low which has caused isolated minor water
ponding and drainage issues. This trend will continue today as
scattered showers and isolated to scattered thunderstorms move east
through the Lower Ohio Valley in a counterclockwise motion around
the low.

Later this morning, we will likely see a break in the precipitation
before convection begins to increase with scattered showers and
storms on the backside of the circulation early this afternoon.
Coverage is expected to become more widespread during this time.
Overall rainfall totals aren`t expected to be too high across the
CWA, but given the nature of convection and the possibility of
training or cells sitting nearly stationary over areas, there
remains the risk of isolated minor flooding. Generally speaking,
rainfall totals are expected to be higher over the eastern half of
the CWA with lower amounts tapering to the west.

Highs today will likely only hit the low to mid 70s given all the
rain and cloud cover, and even though winds will be light, between 5-
10 mph, they will be variable as they follow the same general
counterclockwise direction as the low moves east through the CWA.

Tonight, rain will slowly taper off as the system moves farther to
the east, and as upper ridging and surface high pressure, extending
south from Canada, moves into the region, skies will start to clear.
The best chances for clear will be over southern Indiana.  With near
calm winds and some remaining sky cover, lows are expected to only
fall into the mid to upper 50s. Far southern Kentucky could hold
onto a 60 or two.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 324 AM EDT Wed May 15 2024

Shortwave ridging on Thursday should provide a break from the waves
of showers and storms, with temperatures peaking around 80 degrees.
However, that break will be brief. A southern stream vort max is
expected to eject from the Rio Grande on Thursday to the Ohio and
Tennessee Valleys by Saturday. A surface low will drift slowly from
the Ozarks to the Ohio Valley during this time as well. With plenty
of moisture available, widespread showers and scattered
thunderstorms are expected ahead of this system Friday into
Saturday. High precipitable water values, deep warm cloud depths,
weak shear, and a thin positive area on soundings suggest locally
heavy downpours will be the main threat with this activity. Though
general QPF amounts are in the 1-2" range for the long term, results
will vary widely from one spot to the next due to the convective
nature of the rainfall. As for severe storms, they can`t be entirely
ruled out, but the best chances should be from the southern Plains
through the lower Mississippi Valley to the Southeast where
instability and shear values will be more supportive.

After a possible hiatus in the rain for the second half of the
weekend, chances increase again early next week as additional
disturbances move east from a western upper trough...though
confidence is low this far out in the forecast.

&&

.AVIATION /06Z TAFS THROUGH 12Z THURSDAY/...
Issued at 543 AM EDT Wed May 15 2024

The center of the low pressure system is currently near Louisville.
Observations which have been bouncing from VFR to IFR levels over
short distances are now showing more low level stratus wrapping
around the low and filling in towards the center which happens to be
near SDF. SDF could remain mostly VFR for a couple more hours before
going solidly into MVFR levels. IFR levels will be possible for a
short time, but it`s not expected to last too long. The other sites
are still expected to spend more time under IFR ceilings. Things are
expected to begin improving this afternoon with VFR ceilings
returning this evening, but given how optimistic ceilings have been
in places overnight, wouldn`t be surprised if this happened earlier.
Rain showers/storms have spent some time over SDF and LEX this
morning. Both sites should see some of a break later this morning
before scattered showers and thunderstorms begin developing again
this afternoon. Winds will remain light and variable.

&&

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

&&

$$

SHORT TERM...KDW
LONG TERM...13
AVIATION...KDW