274
FXUS63 KJKL 031004
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
604 AM EDT Wed Jul 3 2024

.KEY MESSAGES...

- Sultry weather continues today through Friday. Afternoon heat
  indices may reach near 100 in some locations.

- A potential for showers and thunderstorms arrives tonight and
  lasts into Saturday as a frontal boundary stalls in the area.

- A cold front finally pushes through as we move into the weekend,
  with dry and somewhat cooler and less humid weather arriving.

&&

.SHORT TERM...(Today through Thursday)
Issued at 603 AM EDT WED JUL 3 2024

Upper level high pressure centered over the Deep South is ridging
northeast over the Appalachians and New England early this
morning. Shortwave troughs rippling through the prevailing
westerlies aloft north of the high will suppress the ridging
southward during the short term period, and somewhat stronger
westerly flow aloft will drop south over KY.

The evolution of the upper level pattern will allow a cold front
to move as far south as the Ohio River tonight before it becomes
largely parallel to the upper level flow and stalls.
Showers/thunderstorms near the front may make it into the forecast
area tonight, with the greatest probability being in our northern
counties. The highest probability of showers/thunderstorms will
be during the day Thursday over the northern portion of the
forecast area as heating/destabilization occurs and a weak wave
ripples through the upper level flow above the nearby surface
frontal boundary.

Deep layer moisture will increase over the area as the ridging
aloft is suppressed and mid-upper level blow-off from earlier
convection advects over us. Models show precipitable water nearing
or exceeding 2 inches arriving from the north northwest tonight
and Thursday. Thunderstorms in this environment would be
efficient rainers and should they train, could cause localized
hydro problems.

.LONG TERM...(Thursday night through Tuesday)
Issued at 255 AM EDT WED JUL 3 2024

The forecast period will begin with mean upper-level zonal flow but
a digging shortwave moving through upper-Mississippi valley will
eject into the Great Lakes. At the surface, a stationary boundary is
draped across the CWA keeping chances of PoP across the area to
start the period but to the west, the aforementioned shortwave will
bring a renewed chance of PoP as a surface cold front approaches the
area. Along and ahead of the front, showers and thunderstorms are
likely through the day Friday into Saturday before the front exits
Saturday evening. Severe chances look to be largely limited with
FROPA as widespread cloud cover will inhibit instability and shear
is fairly weak ahead of the boundary. However, can`t rule out an
isolated severe thunderstorm with FROPA during the day Friday. Also,
there`s forecast 90-99th percentile above climatological
precipitable water values, 2.10" to 2.30", through FROPA is
expected. Which, if these showers and storms are efficient, heavy
rainfall leading to possible hydro issues could be possible before
the front exits on Saturday.

High pressure builds in for Sunday into Monday before another double-
barreled surface low sets up for next week. The first is another
shortwave developing in the upper-Mississippi Valley and ejecting
into the Great Lakes with a cold front crossing through the
Commonwealth. The second feature is a weak surface low riding along
a low-level jet streak. The second feature will bring increasing
showers and thunderstorms to the region Monday afternoon before the
first system drags a cold front through the region on Tuesday.
Showers and thunderstorms are forecast to persist through the day
Tuesday and linger through the remainder of the forecast period.

Overall, the period will highlighted with periods of showers and
thunderstorms that`ll bring much needed rain to the area. Also,
temperatures will return to more seasonal ranges as daytime highs in
the mid-80s to low-90s and overnight lows ranging from the upper-50s
to upper-60s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 308 AM EDT WED JUL 3 2024

Fog will affect some of the deeper valleys during the late night
and early morning hours, but shouldn`t affect TAF sites.
Otherwise, VFR conditions are expected through the period. Winds
will mainly be from the south to southwest at around 10 kts or
less.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HAL
LONG TERM...VORST
AVIATION...HAL