207
FXUS63 KLMK 300703
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
303 AM EDT Sun Jun 30 2024

.KEY MESSAGES...

*   Isolated showers and storms possible this morning ahead of a
    cold front. Drier conditions set in as the front sweeps through
    the region this morning and afternoon.

*   Unseasonably cool temperatures tonight, with lows in the 50s for
    most.

*   Unsettled weather Wednesday through Saturday with daily chances
    of showers and storms. Rain chances on Independence Day 50-80%.

*   Heat index Wednesday afternoon may surpass 100 degrees,
    especially west of I-65.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 302 AM EDT Sun Jun 30 2024

The sfc cold front will be passing through the region this morning,
and is expected to be south of the Ohio River by 12z. Ahead of the
front, moisture convergence in a warm and humid airmass will support
isolated to scattered showers this morning, mainly across south-
central Kentucky. CAMs have been consistent on any cluster of storms
moving into our region this morning will be weakening, given the
weak shear, low level capping, and meager lapse rates available.
Still can`t rule out some folks hearing some rumbles of thunder this
morning, but severe risk appears low.

By the early afternoon, the sfc front will be through just about all
of our forecast area. Sfc winds will become somewhat breezy this
afternoon. We`ll hold on to an isolated shower or storm chance
across the Lake Cumberland region, but elsewhere will be dry and
less humid in a post-frontal airmass. We`ll see a sharp wind
direction change with FROPA, from a WAA southwest flow this morning
to a cooler north flow this afternoon. Temps will be several degrees
cooler than the last few days, with highs in the upper-70s and low-
80s north of the Ohio River, and mid- and upper-80s to the south.

By tonight, the cold front will be well south of the region. Sfc
high pressure will be building across the Great Lakes, and will
enhance CAA into the lower Ohio Valley overnight. Along with
clearing skycover, northerly flow will aid in temps cooling into the
low 50s (southern Indiana) to the low 60s (southern Kentucky), which
is 15-20 degrees cooler than Saturday night`s lows.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 302 AM EDT Sun Jun 30 2024

High pressure over the Great Lakes and a dry atmosphere in place on
Monday will lead to sunny skies and much more tolerable temperatures
and humidity to start July. Afternoon highs will only be around 80
degrees. Dew points should mix out in the afternoon to the lower 50s
and upper 40s...with about a 50% chance of mid 40s east of I-75.
Mostly clear skies will continue Monday night as temperatures tumble
into the middle and upper 50s, which would be the coolest readings
for many since June 12-13.

Tuesday the high will proceed to the Northeast, placing us in
warmer, more humid return flow. Afternoon temperatures should peak
around 90 with dew points about fifteen degrees higher than the
previous day.

Wednesday through Saturday will be characterized by unsettled
weather and daily chances of showers and storms. Though this isn`t
great news for holiday activities, we could use the rain to keep the
D0/D1 conditions in southern Indiana and north central Kentucky from
worsening.

A 5H trough entering the Pacific Northwest today and tomorrow will
work to slightly flatten the large Southeast upper ridge mid-late
week. A cold front advancing from the northwest will approach on
Wednesday, but then weaken and slow its forward progression as its
parent low lifts into northern Quebec and the front runs into the
upper ridge to our south as well as a western arm of the Azores-
Bermuda high at the surface. We may have to wait until an area of
low pressure moves up the front around the Friday-Saturday time
period, and a reinforcing upper wave further suppresses the southern
upper ridge to the Gulf Coast states, before the front finally moves
through. For us this means we`ll be in a warm, humid air mass with
upper waves riding the pressure gradient helping to generate
occasional showers and storms. Right now showers and storms look
like a good bet on Independence Day as GFS IVT shows a slug of
moisture moving through with above normal precipitable water values
shown by GFS and ECWMF.

While organized, widespread severe weather appears unlikely at this
time, strong summertime storms with locally torrential downpours and
gusty winds will certainly be possible.

&&

.AVIATION /06Z TAFS THROUGH 12Z MONDAY/...
Issued at 110 AM EDT Sun Jun 30 2024

High level clouds will continue to stream over the region in the
coming hours ahead of an approaching cold front. VFR conditions are
expected at the terminals, but LEX may have some ceilings near MVFR
threshold by sunrise tomorrow. Will also keep an eye on any
thunderstorm activity this morning along the front, which guidance
has been agreeing fairly well on a 1-2 hour window for BWG around
12z this morning. Otherwise, as the front passes through, expect a
hard shift in wind directions. Post-frontal northwest winds could
get gusty at times during the afternoon and near 20kts.

&&

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

&&

$$

SHORT TERM...CJP
LONG TERM...13
AVIATION...CJP