240
FXUS63 KLMK 130549
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
149 AM EDT Mon May 13 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Active pattern this week with almost daily chances of showers
    and storms through Friday. Best chance for a dry day will be
    Wednesday afternoon and Thursday. Severe weather is not expected.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 328 PM EDT Sun May 12 2024

Afternoon satellite imagery and observations show mostly sunny skies
across southern IN and central KY.  Surface high pressure ridge was
noted from central TN northeast into eastern OH which will set up a
southwest flow regime for our region.  Afternoon temps were quite
pleasant with readings in the 72-78 degree range.  For the remainder
of the afternoon hours, no significant weather is expected.  Temps
will cool into the lower 70s by evening.

For the overnight period, mostly clear skies are expected this early
this evening.  As the night wears on and the ridge axis shifts east,
we`ll see a gradual increase in high cloud cover.  This will keep
temps from dipping too much with most locations seeing lows in the
mid 50s, with the cooler valleys dropping into the lower 50s.

For Monday, an upper level shortwave trough axis over the Plains
will slowly move east while deepening.  Synoptic scale forcing for
lift will overspread the region during the afternoon hours.  Much of
the data suggests a relatively dry morning period, but scattered
rain showers are likely to become more widespread in the mid-late
afternoon period.  Area averaged model soundings show very little in
the wave of instability and wind shear values are quite weak (less
than 20kts).  So while, I can`t rule out a rumble of thunder here or
there, the threat of organized/severe convection is very low.  Highs
will likely see a gradient across the region.  The cooler spots will
be in the southwest with highs in the 70-75 degree range.  For our
north-central and east-central zones, highs of 75-80 are expected.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 328 PM EDT Sun May 12 2024

Monday night through Wednesday...

The medium range forecast starts off unsettled Monday night into
Wednesday as a slow-moving closed low meanders eastward from
Missouri across the Ohio Valley. Scattered showers are likely Monday
night as low-level WAA and moist isentropic ascent increase ahead of
the low pressure system. Forecast soundings show a rather moist
column with limited instability. While PW rises to 1.2-1.4 inches,
PW and IVT are not significantly anomalous (+1.0-1.5 NAEFS SD). The
showers will be efficient rain producers, but fairly typically
weather for mid-May. An isolated rumble of thunder will be possible
with lows in the low 60s.

Rain chances are maximized Tuesday into Tuesday night as the low
moves directly overhead, with deep lift and moisture. Some areas
could destabilize diurnally, but moisture/clouds will keep CAPE
values in check. Plus, deep-layer shear will remain weak, so severe
weather is not anticipated. Isolated to scattered storms may produce
locally heavy downpours, gusty winds, and lightning. Rainfall
amounts of 0.75-1.25 inches are possible through Wednesday, with
some locally convectively-enhanced totals not out of the question.
This could result in some ponding and minor flooding issues in low-
lying or flood-prone areas, but significant flooding is not
expected.

Rain chances linger into Wednesday with moisture wrapping around the
slow-moving system, but an overall drier trend is expected from west
to east Wednesday afternoon and evening. Given the moist
environment, diurnal temperature ranges will be smaller with highs
in the 70s and lows near 60 F.

Wednesday night through Saturday...

Shortwave ridging building east over the Ohio Valley will bring dry
weather Wednesday night through Thursday. Look for mostly clear to
partly cloudy skies with lows in the 50s and highs in the upper 70s
to near 80 F.

Rain chances increase once again Thursday night ahead of troughing
over the Plains and Midwest. This weather system will drag a cold
front toward the region by Friday-Friday night with what should be
plenty of lift and abundant moisture. Some thunderstorms will be
possible, though available instability is unclear at this time
range. At this point, the risk for severe weather appears low.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 147 AM EDT Mon May 13 2024

VFR conditions are expect through 21z, but as a low pressure system
approaches from the west, ceilings will begin lowering into MVFR
levels at BWG. Then, HNB an hour or two later. This trend will
continue east across southern Indiana and central Kentucky. Around
0z Tuesday, IFR ceilings will begin working in from the west, near
HNB. As these ceilings lower, rain chances will begin increasing.
Widespread coverage currently isn`t expected until closer to Tuesday
morning.

&&

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

&&

$$

SHORT TERM...MJ
LONG TERM...EBW
AVIATION...KDW