546
FXUS63 KLMK 170726
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
326 AM EDT Mon Jun 17 2024

.KEY MESSAGES...

*   Persistent early season heat wave expected, with highs well into
    the 90s each day.

*   Heat index values not expected to reach advisory levels, but
    societal impacts are likely.

*   Spotty coverage of afternoon thunderstorms today and Tuesday,
    then dry Wednesday through Saturday, with flash drought
    development possible.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 326 AM EDT Mon Jun 17 2024

Upper ridging remains over the eastern United States while a
surface high sits off the New England coast. High pressure ridging
extends from the high`s center towards the southwest into the
Carolinas. This is keeping southerly wind over the Lower Ohio
Valley. It continues to funnel Gulf of Mexico moisture up the
Mississippi Valley into the Ohio Valley.

Today should be a lot like yesterday, but now the moisture that
worked in yesterday is already here. Precipitable water values will
remain between 1.5-2" over most of the the CWA. Values could drop
just under 1.5" in parts of the Lake Cumberland and Bluegrass areas.
Farther to our west, over western Kentucky, PWATs climb over 2".
That`s a lot of moisture, but warm temperatures can hold a lot of
moisture. Looking at model soundings, the low levels look well
mixed, so even with good instability and moisture, believe the
showers and thunderstorms will be fairly limited today as mid-level
subsidence remains. Lots of sunshine and warm air advection will
lift temperatures back into the low to mid 90s. With dew points in
the upper 60s to low to mid 70s, heat indices will cross the 100
degree mark in some areas. Due to this, a Special Weather Statement
will be issued again today.

Tonight, southern winds will ease as precipitation chances decrease.
Skies will remain partly cloud. Lows are expected to drop into the
low to mid 70s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 326 AM EDT Mon Jun 17 2024

Anomalous upper ridge will continue to strengthen along the East
Coast Tuesday, as it drifts north from the Carolinas into Virginia.
By Wednesday the ridge axis becomes oriented more east-to-west into
the Ohio Valley. As a result most of the week will be hot and dusty,
with precip chances barely touching 20 percent Tuesday afternoon and
dropping off from there.

Temps each day will climb well into the 90s, but with dewpoints only
just touching 70 on Tuesday and dropping off into the lower/mid 60s
later in the week, heat index values will be largely held in check.
Best chance for the heat index to touch 100 will be Tuesday, and
again Thu-Sat as air temperatures climb into the upper 90s. This
heat wave will be most notable for its persistence. No heat-related
headlines are planned at this time, but will ramp up messaging to
core partners as societal impacts are quite possible.

Small rain chances return on Sunday as the upper ridge breaks down
just enough for a cold front to approach the region. At this point
precip chances are no more than 30 percent, with minimal relief in
terms of temperatures.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 146 AM EDT Mon Jun 17 2024

VFR conditions are expected to last through the forecast period.
With the moist airmass overhead, a low chance of precipitation
remains through the period. The highest of the low chances will be
during the afternoon and evening hours. Believe guidance is overdone
on the coverage. There will likely be some isolated convection
during the day, but chances remain too low to keep it in the TAFs.
Continued southerly winds are expected to be a little more gusty
during the afternoon hours.

&&

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

&&

$$

SHORT TERM...KDW
LONG TERM...RAS
AVIATION...KDW