LMK issues Area Forecast Discussion (AFD) at Sep 20, 2:54 PM EDT
297
FXUS63 KLMK 201854
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
254 PM EDT Sun Sep 20 2026
.KEY MESSAGES...
* Unseasonably hot weather will continue area-wide this afternoon
and over southern Kentucky tomorrow, with afternoon heat indices
near 100 degrees.
* While an isolated storm can't be ruled out this afternoon, the
best chances (30-40%) will be tonight into Monday morning near and
north of I-64, and again Monday afternoon and evening along and
south of the Western Kentucky and Bluegrass Parkways. Dry weather
is forecast to rest of the week.
* Milder weather will gradually overspread the area this week, with
highs in the 70s north of an Owensboro to Berea line by Tuesday,
and area-wide by Wednesday. Dry weather and pleasant temps look to
hang around through the weekend.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 253 PM EDT Sun Sep 20 2026
Things are mostly quiet across the CWA at this hour, however an
isolated shower or storm is possible through the afternoon and
evening. This threat is mainly for areas east of I-65 where some
moderate instability has developed, and current visible satellite
imagery shows some scattered agitated cu. A gravity wave did pass SE
through the CWA earlier this morning into the early afternoon,
however it was becoming less defined the farther SE it got, and not
sure how much of a triggering role, if at all, it will play. Other
than that, hot conditions continue today with temperatures already
in the low to mid 90s. SDF has good chance to tie the record of 96
degrees, if not break it, however some upper clouds have begun to
stream in and that could be a limiting factor. Thanks to some drier
dew points, heat indices are mostly going to peak in the 95 to 100
degree range, although some values up near 105F are still possible
in the Heat Advisory. No changes planned to that.
As we move into late evening and tonight, focus shifts to a weak
surface boundary sinking southward into the Ohio River Valley
region. This feature may be able to trigger isolated to widely
scattered showers or a few storms as it does so. Modest instability
looks to remain overnight (ML CAPE values 500-1000 J/KG), and this
combined with deep layer shear in the 25-35 knot range should be
enough for perhaps a few stronger storms capable of gusty winds. SPC
Day 1 Marginal Risk covers the low but non-zero probs for a damaging
wind event along and north of I-64 through the overnight.
As we move into Monday, the surface boundary will work into southern
KY while surface high pressure starts to build into our north in the
post-frontal wake. Expecting most of the convective activity will be
mainly diurnally driven and across the southern half of the CWA
closer to the front. Here there is pretty high confidence in 1500-
2500 J/KG of ML CAPE developing along with sufficient deep layer
shear for some organized updrafts. Another Marginal Risk is in place
for areas along and southeast of a Bowling Green to Lexington line
where an isolated damaging wind gust can't be ruled out.
Temperatures will start to cool across our northern CWA with highs
in the low and mid 80s across southern IN and northern KY. Across
southern KY, we'll still hold onto hot and humid conditions with
peak temps in the low 90s.
The upper ridge over the southern CONUS continues to break down on
Tuesday, allowing the surface front to sink south of KY. A shortwave
embedded in the zonal flow across the Ohio River Valley will
approach and may be a catalyst for additional shower and storm
coverage across our SE CWA. Will keep pops there, but the good news
is that temps will be notably lower. Highs in the mid to upper 70s
are expected across southern IN and northern KY, while southern KY
looks to top out in the low 80s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 253 PM EDT Sun Sep 20 2026
Wednesday - Sunday...
The shortwave trough axis will be pushing east of the area by
Wednesday morning, and will close off over the mid Atlantic states
as we move into late week. Meanwhile, an H5 Omega Block will be
building from the western Gulf up through the western Great Lakes,
including our area. At the surface, an expansive area of high
pressure over eastern Canada will extend influence into our region.
The end result of this pattern will be a period of dry weather from
mid to late week through the weekend. May need to linger a few small
rain chances along the I-75 corridor Wednesday morning as the trough
axis pushes east, otherwise will be dry elsewhere.
In addition to the dry conditions, temperatures will be notably
cooler and more comfortable, albeit still around normal for this
time of year. Looking for highs mostly in the mid to upper 70s each
day Wed-Sat, with temps more in the lower 70s for the Bluegrass
region. By Sunday, some low 80s will likely return. Dew points will
sink into the upper 50s and low 60s through mid week, and then down
more into the low and mid 50s for the weekend. This will allow for
some crisp mornings with lows in the low to mid 50s for the weekend.
&&
.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 138 PM EDT Sun Sep 20 2026
VFR will prevail for much of this TAF period, although some notable
weather impacts are possible. Surface winds are steady out of the
SSW this afternoon, with perhaps a few gusts up around 15 to 20 mph.
Winds will slacken around sunset, and will go light and variable as
a weak frontal boundary sinks southward through the I-64 corridor.
Isolated showers and storms are possible overnight with this frontal
passage, however coverage and confidence are quite low. Surface
winds will eventually take a light N or NE component through
tomorrow along with some lower clouds possibly working into the
northern TAF sites. There are some probs for IFR conditions at HNB,
but for now will hint at MVFR as the lowest ceilings have trended
slower and may end up just north of the area.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for
KYZ023>028-053-061>063-070>076.
IN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for
INZ083-089.
&&
$$
SHORT TERM...BJS
LONG TERM...BJS
AVIATION...BJS
Source: LMK issues Area Forecast Discussion (AFD) at Sep 20, 2:54 PM EDT (https://mesonet.agron.iastate.edu/p.php?pid=202609201854-KLMK-FXUS63-AFDLMK)
---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!