389
FXUS63 KLMK 192259
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
659 PM EDT Sat Apr 19 2025

.KEY MESSAGES...

*  Isolated to scattered showers and storms possible this
   evening in southern Indiana and northern Kentucky. A few
   stronger storms are possible with gusty winds the main
   threat.

*  Showers and storms expected very late Sunday night into Monday
   morning, severe threat is very low.

*  Dry and seasonable Tuesday and Wednesday before rain chances
   return later in the week.

&&

.UPDATE...
Issued at 659 PM EDT Sat Apr 19 2025

Upper level wave has pushed northeast of the region and the threat
of additional convection appears to be over.  Not seeing much
additional low or high level forcing to get stuff going again.  Weak
frontal boundary will drop southward and settle across the region
overnight.  Partly to mostly cloudy skies are expected.  The front
will lift back northward on Sunday.  Current forecast has this well
handled.  However, will go ahead and update to remove PoPs for the
remainder of the evening and adjust near term weather elements
closer to observations.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 303 PM EDT Sat Apr 19 2025

Things are dry across the CWA at this hour, however there is another
round of convection set to slide across the northern part of our CWA
late this afternoon into the evening. Overall, the atmosphere has
struggled to destabilize due to a couple of factors. 1.)
Convectively reinforced outflow from this morning`s wave of
convection has kept our north at least somewhat stable, and 2.)
increased upper sky cover from waves of convection has limited
heating a bit. There was a brief window of clearing on satellite
imagery this afternoon, but that window is already rapidly closing.
Nevertheless, 500-1000 J/KG of ML CAPE has developed along and south
of the outflow boundary. Overall, storms aren`t very impressive
upstream, but will keep an eye on things through the evenings. SPC
Slight Risk looks overdone but won`t completely rule out an isolated
damaging wind gust.

Things will quiet down later this evening (by 8 or 9 PM) as this
wave pushes through. From there expect just a few showers across our
north where the boundary has stalled. By tomorrow, the front will
begin to lift back northward as a warm front as a strong surface low
rapidly moves from the Red River Valley up into the mid Mississippi
River Valley. Should be a pretty mild day given strengthening
southerly flow and some breaks in the clouds in the broadening warm
sector. Going with highs in the low and mid 80s across the area, and
may end up a bit warmer if more breaks in the clouds are realized.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 303 PM EDT Sat Apr 19 2025

Storm system will lift north out of the Midwest and into the Great
Lakes Sunday night into Monday morning. This will push a cold front
through the area early Monday morning. Strong LLJ will be out ahead
of the boundary providing amble shear but given the timing of early
Monday morning, lack of instability will keep the severe threat very
low. Showers and storms will slowly push eastward during the day
with highs into the low/mid 70s.

Cold front sags southward across the TN Valley as weak sfc high
builds in over the Great Lakes and the Ohio Valley. Aloft, we will
be under a weak zonal flow. Tuesday and Wednesday look relatively
dry but depending on how far south the surface boundary goes there
could be scattered showers/storms possible across the the KY/TN
border into the Lake Cumberland region.  Highs on Tuesday will be in
the mid/upper 70s warming to near 80 on Wednesday.

Weak, mid-level shortwave will progress northwest out of the central
plains and into the Ohio Valley on Thursday. This will push the
stalled boundary to the south back northward as a weak warm front.
Showers and storms will start to increase for Thursday and high
still near 80 degrees.

Friday into the weekend will feature some wet and unsettled weather
as a cold front coming out of the Upper Midwest Thursday night into
Friday become quasi-stationary over the Ohio Valley. Models are
picking up on a weak sfc low forming along this boundary and lifting
northward along the stalled boundary sometime from early Saturday
into Sunday. While this has been a consistent trend in the models as
was mentioned in the previous discussion, there remains wide
discrepancies in exact timing and strength of this system so overall
confidence remains low. We will see wet weather over a couple of
days but total forecast rainfall looks to range from around three
quarters of an inch to an inch and a half over central KY with the
lower amounts across the Bluegrass and high amounts back to the
southwest towards western KY.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 659 PM EDT Sat Apr 19 2025

Outflow has surged southward and convection has waned across the
region.  With the lack of significant low-level or synoptic scale
forcing, current thinking is much of the rest of the night will be
convection free across the region.  VFR conditions are expected this
evening.  However, data still shows MVFR cigs possible at the
northern TAF sites late tonight through early Sunday morning.  Winds
will gradually slacken this evening and then shift to the northeast
overnight before shifting back to the southeast Sunday morning.  VFR
conditions are expected for much of the day on Sunday.

&&

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

&&

$$

UPDATE.......MJ
SHORT TERM...BJS
LONG TERM....BTN
AVIATION.....MJ