165
FXUS63 KLMK 021855
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
255 PM EDT Sun Jun 2 2024

.KEY MESSAGES...

*   Chances of isolated showers and thunderstorms today with
    gusty winds and heavy rain being the main hazards.

*   Scattered storms will be possible Tuesday and Wednesday. A few
    strong to severe storms will be possible, especially Wednesday.
    The main threats will be heavy downpours and gusty winds.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 254 PM EDT Sun Jun 2 2024

Synoptically, 5h shortwave responsible for today`s weather will
continue to exit to our east allowing for zonal flow aloft and weak
ridging to advect over the OH Valley. Low level cyclonic flow is
evident on radar as showers pinwheel around the base of the surface
low centered over south central Indiana, while GOES-16 satellite
imagery reveals breaks in the clouds.

This increased sunshine will help destabilize the region allowing
for isolated to scattered showers and possible thunderstorms
throughout the afternoon and into the the early evening. SPC
mesoanalysis shows a ridge of instability over our CWA with SBCAPE
values around 1500 J/kg. Shear is minimal with VWX VWP and AMDAR
soundings out of SDF showing light winds throughout the column.
Slight veering within the column is indicative of the weak warm
advective pattern in place, but updrafts will struggle due to weak
mid level lapse rates. With that said, sufficient dry air aloft and
DCAPE values around 1000 J/kg along and west of I-65 could produce
some strong winds with any stronger convection. With that said, not
expecting any severe weather with today`s activity.

Tonight, expect winds to subside and clouds to clear as weak high
pressure briefly builds over the region. Some models suggest fog
development by early Monday morning so will add mention of patchy
fog, which could affect the morning commute.

Monday is shaping up to be a rather pleasant day with partly cloudy
skies and afternoon temps rising into the mid 80s, while light SSW
winds push dewpoints into the mid to upper 60s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 254 PM EDT Sun Jun 2 2024

Dry weather will continue into Monday night, with some patchy valley
fog possible in the Blue Grass and Lake Cumberland regions with
mostly clear skies and nearly calm winds. Lows will be in the lower
and middle 60s.

Rain chances return on Tuesday as a small 5H vort max crosses
Illinois helping to spark showers and storms in 1.75" precipitable
water air. Shear and mid-level lapse rates will be weak, but there
will be enough instability to get thunderstorms going in the
afternoon as the mercury meets or slightly exceeds convective
temperatures in the middle 80s with dew points in the middle and
upper 60s. Scattered pulse storms are expected, with the most likely
threats, other than the lightning threat that accompanies all
thunderstorms, being locally heavy downpours and precipitation
loading induced gusty winds.

On Wednesday vapor transport from the western Gulf will increase
into the Ohio Valley ahead of a cold front approaching from the
northwest. A spoke of lower 5H heights reaching southeast from the
main upper low over southern Manitoba will reach southeast into our
region as well. Deep layer shear may be a little stronger on
Wednesday in association with swifter 500mb flow south of the
Manitoba low, but still shouldn`t be terribly impressive. CAPE is
progged to be a bit weaker on Wednesday with continuing weak mid-
level lapse rates, possibly partly a result of morning clouds and
showers. CSU-ML has been very consistent over the past four days
pegging Wednesday as our most likely day for severe weather this
week. This is still the case, but probabilities have decreased
slightly. The best upper level divergence will remain well to our
north, and the surface low will be far off in western Ontario.
Nevertheless, we`ll still have plenty of instability and moisture
for showers and storms, and with the incoming cold front, some
strong to severe storms do still appear possible. Again the main
threat would be gusty winds given the expected pulse nature of the
storms and high freezing heights.

Thursday through Sunday will lean drier as the Canadian upper low
pushes east into New England and surface high pressure tries to
build in from the Plains and Midwest. Will hold on to some chance of
rain given our position on the edge of cyclonic flow aloft, but will
keep PoPs low.

Temperatures will cool off a bit as we head into the weekend. Highs
are expected to slip from the mid 80s Thursday to around 80 Friday
and Saturday. CPC outlooks show increased chances of cooler than
normal temperatures for much of the first two weeks of the month.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 254 PM EDT Sun Jun 2 2024

Latest surface analysis reveals low pressure over Indiana with a
weak cold front stretching south across the TN Valley, while current
radar shows scattered showers moving generally west to east across
the region. Breaks in the cloud cover will allow for increased
diurnal heating, which will help spark additional showers and
possible thunderstorms this afternoon. AMDAR soundings out of SDF
continue to show light wind columns with meager lapse rates, which
adds to low confidence in thunderstorms. Tonight, expect winds to
slacken and clouds to clear leading to potential fog development by
early Monday morning. VFR conditions are expected shortly after
sunrise.

&&

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

&&

$$

SHORT TERM...CG
LONG TERM...13
AVIATION...CG