768
FXUS63 KLMK 201920
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
320 PM EDT Sat Jul 20 2024

.KEY MESSAGES...

*   Shower and storm chances will continue to increase across
    southern KY for Sunday, then everywhere else by next week.

*   Locally heavy rainfall possible with any of these showers and
    storms.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 319 PM EDT Sat Jul 20 2024

Sfc boundary has lifted northward as a warm front across southern KY
and northern TN. This is evident on the Kentucky Mesonet where you
can see a spread of dew points in the upper 60s to around 70 along
the KY/TN border with low/mid 60s further north along the Ohio River
into the Blue Grass. There is even a steep PWAT gradient from north
to south with 1.5"-1.7" along and just north of the KY/TN border and
south of the parkways with 1.1-1.4" from southern IN to just north
of the parkways. Current radar images from area WSR-88d show a few
isolated showers/storms forming along the KY/TN border, just south
of the warm front. This remains the best chance for precipitation
this afternoon before activity diminishes with the loss of daytime
heating. While the current HRRR wants to develop some isolated
activity northward later this evening into the overnight, I just
don`t feel there will be enough instability or lift to develop this
activity, so continued to trend of diminishing precipitation chances
this evening and overnight. Sfc low currently located over the Deep
South will work along the quasi-stationary boundary turned warm
front that stretches from Louisiana through the TN Valley and
eastward towards the Eastern Shores of VA. This will help to
increase mid/upper cloud cover over the region overnight. Even with
the cloud cover, the increased low-level moisture may increase the
possibility of patchy fog across our south in areas near and south
of the sfc boundary.

As the aforementioned sfc low slowly works into Kentucky during the
day tomorrow, it will continue to lift the sfc boundary further
north towards the Ohio River and into the Blue Grass by tomorrow
afternoon. An upper low coming dropping southward out of the Upper
Midwest will open up into a trough and start to swing through the
region as well during the day. This will help to increase the low
level moisture northward as dew points climb into the mid/upper 60s
across north central KY and southern IN while we will have low 70
dew points across southern KY. More scattered showers and
thunderstorms will be likely tomorrow afternoon. HREF ensemble mean
continues to show 1000-2000 J/kg of SBCAPE across a large portion of
central KY tomorrow afternoon but with meager shear and lacking any
strong lifting mechanism, while there remains a chance for
showers/storms tomorrow afternoon the main impacts will be heavy
rain and occasional gusty winds from any activity that forms.
Temperatures could be quite warm tomorrow working into the mid/upper
80s. Temperatures could end up being a challenge depending on shower
activity as well as cloud cover from the aforementioned systems
working across the region tomorrow.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 319 PM EDT Sat Jul 20 2024

Relatively stationary frontal boundary draped over Kentucky during
the next week will bring showers and thunderstorm chances every day
with the highest confidence being Monday and Tuesday.  Confidence is
increasing (as the forecast pattern has been consistent for several
days) that several rounds of storms will bring locally heavy
rainfall. Model forecast soundings continue to show a low severe
threat with the main concern focusing on the heavy rain potential
with plenty of column moisture and elevated PW amounts. Gusty winds
and small hail would be secondary threats with the strongest storms.
Locally excessive rain could result in flooding, especially in the
areas with best coverage across the southern and eastern portions of
the forecast area. Concerning max temperatures, the work week will
be slightly below normal with highs ranging in the low and mid 80s.
Temperatures will be highly dependent on storm/cloud activity each
day.  Heading to the end of the week and into the weekend, max temps
will climb to around normal in the mid to upper 80s.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 154 PM EDT Sat Jul 20 2024

Forecast continues to call for VFR flight categories for most of the
locations through the period. The only exception would be the
potential for fog development overnight into tomorrow morning for
RGA and BWG. Sfc boundary has worked northward as a warm front into
southern KY. SCT to BKN clouds between 5000-10000Ft will be around
and there is a chance of a few isolated to potentially scattered
showers or storms this afternoon or evening. The other feature we
will monitor will be an upper level wave pushing in from the Upper
Midwest. There is plenty of moisture ahead of this so increased
mid/upper clouds and he potential for increased precipitation
tomorrow morning into he afternoon.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...MCK
AVIATION...BTN