205
FXUS63 KLMK 011716
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
116 PM EDT Sat Jun 1 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Rain and storm chances this weekend continue into next
    week. Temperatures and dewpoints will also be on a steady
    increase into next week.

&&

.UPDATE...
Issued at 1026 AM EDT Sat Jun 1 2024

Showers will continue to stream northward into the region ahead of
an advancing 5H shortwave trough over the Mississippi Valley and a
surface low near Saint Louis. Instability is very weak but a few
claps of thunder can`t be entirely ruled out. Showers west of I-65
this morning will slowly spread east into the Blue Grass and
southeast Indiana this afternoon and evening. Rain amounts will be
on the light side, with only about a 20% chance of any one spot
seeing more than 0.75", with the best chances west of I-65.

Slightly gusty winds are already in place, with some gusts around 25
mph observed in western Kentucky beneath a compact low level jet
from Alabama to Indiana this morning. If some deeper convection can
get going this afternoon we could see a few slightly enhanced gusts
in the Bowling Green region of southwestern central Kentucky.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 326 AM EDT Sat Jun 1 2024

A shortwave trough axis will slowly move from the mid Mississippi
River Valley through our region today and tonight. Ahead of this
feature, we do see an uptick in low level jetting to around 30-35
knots or so which will aid in PWAT values surging toward 1.75" or so
later today. Some weak isentropic lift may also be present in
addition to some very meager elevated instability (250 J/KG or less
of MU CAPE). Overall, this should result in widespread light rain
overspreading the area later this morning into the afternoon. Could
see a few pockets of moderate rain as well as a few embedded rumbles
of thunder. Overall, expecting around .33" to .5" for most, with
some localized areas closer to .75" possible.

Trough axis is slow to move through, so will keeping lingering pops
in tonight. May see some fog develop across our NW toward dawn on
Sunday.

Should be a notable temp gradient from W to E today. Expecting
mostly low to mid 70s along and west of I-65. Meanwhile, areas
farther east should be more in the mid to upper 70s given a bit more
time to "heat" up before precipitation onset. Smaller diurnal range
into tonight, given the heavy cloud cover. As a result, only
expecting to drop into the low and mid 60s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 326 AM EDT Sat Jun 1 2024

Sunday - Sunday Night

Shower chances will linger Sunday morning and possibly into the
afternoon as the weak mid-level wave and associated sfc low scoots
off to our northeast. Low level ridge will be eroding the moisture
transport throughout the day, but still expect a warm and muggy
airmass with dewpoints in the upper 60s and temperatures peaking near
80. Along with the warm airmass, some breaks in the clouds during
the afternoon would amplify the possibility of realizing marginal
instability, especially across south-central Kentucky. There won`t
be much forcing left by then, but perhaps some pulse storms could
pop up in the afternoon hours, leading to some localized downpours.

Eventually a drier airmass will arrive by Sunday night, leading to a
brief period with no precip mention in the forecast. Dry weather
will continue into Monday morning. Normal temperatures expected
overnight, with readings in the low and mid-60s.


Monday - Wednesday

A summer-like pattern will take over for the first half of next
week, with daily shower and storm chances as a parade of weak waves
provide forcing in a warm and humid environment. If there`s any
chance for a day to be drier than the others, it will be Monday. Low-
level ridging will help keep dry conditions for most of Monday,
especially for areas east of I-65. WAA regime will set up Monday to
be the warmest day of the long term period, with afternoon highs
peaking in the mid- and upper-80s.

Confidence on timing and coverage of each wave of precip and storm
chances remains low. Both Monday and Tuesday afternoon will pose the
risk for pulse-type thunderstorm development in an unstable
environment with steep low level lapse rates. Wednesday brings our
highest PoPs of the week as a cold front sweeps through the region.
This frontal boundary will provide better forcing for showers and
storms, with the potential for some strong to severe storms not out
of the question either.


Thursday - Weekend

Very low confidence in weather elements during the
period as model uncertainty increases substantially. All in all,
forecast indicates slow lowering trend in rain chances towards the
weekend with slightly cooler temperatures.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 115 PM EDT Sat Jun 1 2024

An upper wave over the mid-Mississippi Valley is bringing light rain
to the region. These showers will continue to push eastward this
afternoon and evening. No nearby lightning activity has been
observed thus far and though a few rumbles of thunder can`t be
entirely ruled out this afternoon and evening, chances are low enough
to leave out of the TAFs for now.

Ceilings will lower as the atmosphere continues to moisten ahead of
the wave. Didn`t go quite as pessimistic as some guidance but still
brought in high-end IFR ceilings for most of the TAF sites after
midnight tonight into Sunday morning.

&&

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

&&

$$

UPDATE...13
SHORT TERM...BJS
LONG TERM...CJP
AVIATION...13