936
FXUS63 KLMK 311459
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1059 AM EDT Fri May 31 2024

.KEY MESSAGES...

*   Dry weather and below normal to normal temperatures expected
    through Friday night.

*   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 1059 AM EDT Fri May 31 2024

It`s another nice late spring day with high pressure centered over
the upper Ohio Valley. All forecast parameters are in good agreement
with reality; no significant changes are needed at this time...did
slightly knock afternoon dew points down east of I-65.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 251 AM EDT Fri May 31 2024

Dry and pleasant weather will continue today as high pressure
shifts slightly from the Great Lakes to the Appalachians. However,
expect a bit more cloud cover than yesterday, with upper level
cirrus increasing later today from the west that is associated with
a 500mb shortwave. NBM is a bit aggressive with the cloud cover this
morning, so will go against the NBM guidance and keep skycover
mostly clear/sunny to start, but will see the cloud cover increase
later this afternoon and especially this evening and tonight.
Temperatures will reach the upper 70s to around 80.

For tonight, expect mostly cloudy skycover as a mid-level shortwave
ejects out of Arkansas. It`ll be dry for most of the region tonight,
but will introduce a 15-20% PoP after 06z for our counties west of I-
65 as the eastern periphery of the moisture transport axis begins to
work into central Kentucky and southern Indiana after midnight.
Model soundings show lingering dry air in the lowest 1km between 06-
12z Saturday morning, so perhaps some virga in the predawn hours
before we fully saturate the column. Better chances for accumulating
precip arrive in the Long Term period.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 251 AM EDT Fri May 31 2024

After nearly a week of dry weather for most, rain will make a return
to the region on Saturday. Models prog modest isentropic lift along
~305K surfaces ahead of a compact shortwave that will tumble into
the Ohio and Tennessee Valleys on Saturday. Deeper moisture with
Gulf of Mexico origins will be drawn northward ahead of this
shortwave, and the combination of lift/forcing in conjunction with
the deeper moisture will promote rain shower development as early as
Saturday morning. We could see `waves` of rain through the weekend
as the shortwave slowly advances eastward. Model soundings over
southern IN and central KY show very poor low and mid level lapse
rates, indicating that instability will be at a minimum. The lack of
instability should keep overall thunderstorm chances low, and any
strong/severe storm chances near 0% despite some marginal deep layer
shear in the environment.

Warmer and more humid conditions return by early next week and will
likely continue through at least midweek as the main jet flow/energy
stay confined to the northern U.S. Subtle shortwaves could tumble
into the region during this timeframe and spark off showers/storms
any time of the day or night, but outside of those waves, most
precipitation chances will be driven by mesoscale features and
likely be highest in the afternoon and early evening hours. A fairly
modest upper level trough (by early June standards) and surface cold
front looks to pass through the region by late Wednesday or Thursday
and should bring a return to cooler temperatures and lower dewpoints
by Friday into next weekend.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 649 AM EDT Fri May 31 2024

With high pressure shifting east today, VFR conditions continue for
the period. Dry weather with ESE winds around 10kts with some
occasional afternoon gusts to 18-20kts possible. High level clouds
will be on the increase throughout today ahead of our next weather
system. Ceilings develop by this evening, and lower through the
overnight hours. VCSH will become possible towards the end of the
TAF period. Some marginal LLWS could be possible tomorrow too, but
confidence is not high enough to include in TAFs for being this far
out.

&&

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

&&

$$

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