370
FXUS63 KLMK 291410
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1010 AM EDT Wed May 29 2024

.KEY MESSAGES...

*   Mainly dry weather and below normal temperatures expected
    through Friday.

*   Rain and storm chances return for the weekend and continue into
    next week. Temperatures and dewpoints will also be on a steady
    increase into next week.

&&

.UPDATE...
Issued at 1009 AM EDT Wed May 29 2024

Showers have begun to blossom over central Indiana this morning in
association with a weak surface trough and cold temperatures aloft.
This activity will push to the south and bring a small chance of
rain to southeast Indiana and the Kentucky Blue Grass this
afternoon, along with some possible new development as the mercury
rises well past convective temperatures in the mid 60s. With
precipitable water values well below normal, coverage will be sparse
and most locations will remain dry. Capping and weak instability
will limit thunder chances.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 308 AM EDT Wed May 29 2024

An upper level shortwave trough and very weak sfc reflection will
continue to rotate southeast from the Lower Great Lakes across the
Ohio Valley today. Right on the heels of this wave, high pressure
will expand from the Plains to the Upper Midwest. Northwesterly
winds are fairly light this morning, but expect breezy conditions to
develop by mid to late morning. Gusts to 20-25 mph are likely for
the afternoon hours.

The core of the mid/upper level shortwave trough and associated
deeper moisture will pass to our northeast across OH. However,
northerly low-level flow will advect some moisture SSE over southern
IN and central KY. Look for an increase in cloud cover beginning
late morning, with SCT-BKN low clouds lingering throughout the
afternoon hours. Cloud cover will be thicker across the northern
half of the forecast area, with more sun in southern KY. The brief
uptick in moisture and wave streaming overhead could kick off a few
isolated showers from southern/SE Indiana across the Bluegrass
Region this afternoon and evening. Cannot completely rule out a
rogue lightning strike northeast of Lexington, but the chances are
slim due to very limited, shallow CAPE.

Most will enjoy a dry day with a steady NW breeze. Highs will range
from the upper 60s/low 70s in SE IN and the Bluegrass to the mid 70s
in south-central KY. Cloud cover diminishes this evening and
overnight as high pressure noses in from the northwest. Winds will
also diminish quite a bit after sunset, which should set the stage
for a cool night with some fog. Patchy dense fog seems possible
early Thursday given elevated soil moisture and temperatures
dropping into the lower 50s in many areas.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 308 AM EDT Wed May 29 2024

Dry and quiet weather will continue Thursday and Friday as an upper
level ridge shifts from the central U.S. into the eastern CONUS. The
proximity of the ridge and surface high pressure will promote
subsidence aloft and keep rain chances near 0% for this timeframe.

It`s not until Saturday that we begin to see some changes to the dry
and quiet pattern we`ve grown accustomed to. Southerly return flow
on the western side of the surface high pressure and upper ridging
will help to advect in a more moist/slightly humid airmass ahead of
an approaching shortwave trough and surface low pressure. Models are
in fairly good agreement of showers and storms developing ahead of
the trough/low, but vary some on the timing and arrival of said
feature. Latest data seems to suggest higher chances for
precipitation later in the day Saturday, and it could continue into
Sunday as the low travels eastward at a fairly slow pace. Model
soundings reveal very poor lapse rates and near moist-adiabatic
profiles with the arrival of precipitation, so instability will be
very minimal. Some marginal shear (25-30kts 0-6km shear) will be
present, though, so if we are able to destabilize some, can`t rule
out isolated strong storms during the afternoon and evening hours
Saturday.

Upper level flow/pattern going into early next week looks quite
disorganized and weak as the main jet energy remains well off to our
north. Within the weaker westerly flow aloft, though, models prog
subtle shortwaves and/or vort max`s to wobble into the Ohio and
Tennessee Valleys and `spark` off rounds of showers and storms.
Timing these individual features this far out is a bit difficult, so
PoPs during this timeframe will remain elevated and broad-brushed to
account for precip potential.

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 649 AM EDT Wed May 29 2024

VFR conditions appear likely for much of this TAF period. A
shortwave trough will rotate southeast across the Ohio Valley today.
Northerly low-level flow will advect lower level clouds between 3-5
kft over southern IN and north-central KY by late morning. Expect
SCT-BKN ceilings to linger through much of the afternoon, with less
cloud cover across southern KY.

NW winds will gradually increase this morning. Gusts to 15-20 kts
are likely late morning into the afternoon hours. Winds will
diminish once again with sunset. Cannot rule out fog late tonight
into early Thursday morning, but confidence is low at this time on
IFR/LIFR conditions.

&&

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

&&

$$

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