256
FXUS63 KLMK 042355
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
755 PM EDT Thu Jul 4 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Scattered thunderstorms are forecast today, and thunderstorms
    will be capable of torrential downpours, gusty winds, and
    intense lightning.

*   Isolated flash flooding is possible today, especially across
    portions of southern Indiana and the Louisville Metro where
    heavy rain occurred yesterday. A Flood Watch is in effect for
    the most vulnerable locations.

*   Unsettled weather will continue through Friday with daily
    chances of showers/storms. Isolated damaging wind gusts,
    torrential rainfall, and lightning will be the primary hazards.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 315 PM EDT Thu Jul 4 2024

Just cancelled a portion of Severe Thunderstorm Watch 505, as the
line has pushed east of those area. A significant chunk of the watch
remains across portions of central and east central KY through 7 PM
EDT.

Currently a broken line of storms is moving through central
Kentucky. This line is bringing gusty winds, torrential rainfall,
and lightning. There is a non-zero tornado risk associated with this
line as slightly increased low level shear may allow for curling
within the line. A nose of 2500-3000 ML CAPE extends from the mid-
Mississippi Valley into central Kentucky. Best 0-3km shear is over
southern Indiana and northern Kentucky around 30-35kts. Therefore,
the northern half of the line is cold pool driven and the southern
half of the line is more pulse-like and has a higher potential for
microbursts. As this line continues over the Bluegrass, it will
outrun the best forcing and instability and begin to weaken.

Isolated convection outside of the line is still possible through
the evening hours.

In the overnight hours, winds will relax and skies will thin. Patchy
dense fog is possible in areas that received rain today. Low
temperatures in the morning will be in the low-mid 70s.

In the mid-morning, yet another round of showers and storms will be
possible as a weak shortwave moves through the lower Ohio Valley.
Scattered showers and storms will move through central and northern
Kentucky mid morning into the early afternoon. As these showers
reach the Bluegrass in the early afternoon, ample heating and a less
worked over environment will allow for some stronger storms. Main
threats will be gusty winds, lightning, and torrential rainfall.

The cold front associated with the low pressure system over the
great Lakes will move through the region in the afternoon and bring
much drier and cooler weather behind the front.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 315 PM EDT Thu Jul 4 2024

Cooler drier air will in advect in behind the departing cold front
Friday night into the weekend. Noticeably more comfortable dew points
in the low/mid 60s and temperatures near normal will be associated
with a sfc high that works in over the Ohio Valley on Saturday then
pushes east-northeast by Sunday afternoon. Highs will be mainly in
the mid 80s on Saturday with lows down in the low 60s Saturday
Night/Sunday morning. As upper heights increase during the day
Sunday, it will be warmer Sunday with afternoon highs in the upper
80s.

Pattern for early next week will feature strong ridging across the
western US with upper ridging out over the Atlantic. Longwave trough
across the central US will slowly work eastward through the first
half of the week. Current deterministic models show tropical cyclone
Beryl making landfall along the TX/Mexico border sometime Sunday
night early Monday morning. Some of this moisture may get pulled
north-northeast ahead of the approaching trough. Shortwave trough is
anticipated to cross the Great Lakes and Ohio Valley Tuesday into
Wednesday. This will keep chance of showers and storms in the
forecast (20-30 percent) for most of next week with higher PoPs (40-
60 percent) during the day on Tuesday. Highs for next week will
remain close to seasonable norms in the upper 80s for highs and
mid/upper 60s for lows. The exception looks to be Monday where highs
near 90 are possible.

&&

.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 754 PM EDT Thu Jul 4 2024

Things have quieted down across the region as most t-storm activity
has died off in the past couple of hours. Still have a frontal
boundary draped across southern IN where additional development
could occur, but coverage should be isolated and low confidence. So,
will keep an optimistically dry forecast tonight. Did put in some
smoke and haze at SDF after 9 or 10 pm as climatology says firework
smoke will cause reduced vis. Also have some BR mentioned at the
other TAF sites in the pre-dawn hours.

Focus shifts to another complex of storms morning into the early to
mid afternoon from W to E across the area. Put in Prob30 mention for
TSRA for now to account for that line of storms. Thereafter, a cold
front passes through with steady W and NW winds through the
remainder of the afternoon/evening.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Flood Watch until 8 PM EDT /7 PM CDT/ this evening for
     KYZ023>025-030.
IN...Flood Watch until 8 PM EDT /7 PM CDT/ this evening for INZ076-
     083-084-089>091.

&&

$$

SHORT TERM...SRM
LONG TERM...BTN
AVIATION...BJS