840
FXUS63 KJKL 171111
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
711 AM EDT Mon Jun 17 2024

.KEY MESSAGES...

- Hot weather persists through the week. Afternoon heat indices
  may peak around 100 at some locations through Tuesday.

- There is also a possibility of thunderstorms today, Saturday,
  and Sunday. The greatest probability is in the afternoon and
  evening hours each day.

&&

.SHORT TERM...(Today through Tuesday)
Issued at 334 AM EDT MON JUN 17 2024

The latest upper level map features high pressure centered over
the southeastern CONUS, while an anomalously strong double-
barreled low is spiraling over central Canada. A positively-
tilted trough extends southwest through the West Coast, with an
embedded low churning across the Pacific Northwest. At the
surface, high pressure is occupying most of the Eastern Seaboard.
A cold front extends from the Upper Midwest back through the
central Plains, while a warm front aligns from the Great Lakes
through the Ohio Valley. Eastern Kentucky is now firmly in the
warm sector, with dew points 10 to 20 degrees higher at most
locations compared to last night at this time.

The models are in good agreement through the short term, with the
southeastern CONUS upper level high gradually moving north and
strengthening with time. At the surface, high pressure will become
more centered over the northern Atlantic by late Tuesday, with
surface ridging expanding back west across the Appalachians by
that time.

This will result in plenty of heat and humidity, as well as
afternoon and early evening convection for today across eastern
Kentucky. Highs today will be similar to yesterday, generally
lower 90s, with a few spots getting into the lower-end of the mid
90s. These temperatures, combined with dew points in the lower
70s, will result in peak heat indices of around 100 degrees.
Afternoon/early evening convection will peak in coverage across
our southeastern terrain; however, given the weak shear, outflow
boundary migration will allow for the threat of isolated to
scattered convection over most of the forecast area at some point
through the day. This convection will die off by late this
evening, with fog likely a bit more prevalent, given the better
convective coverage and balmy conditions in place. Lows will range
from the mid to upper 60s in the typically cooler valley
locations, to the lower 70s elsewhere.

On Tuesday, an influx of high clouds may keep highs just a shade
cooler compared to today; however, peak heat indices will be near
100 degrees once again, as dew points will still be near or just
over 70 degrees at most locations. Higher 500 mb heights should
keep a lid on most convection, although a stray shower or storm
can not be completely ruled out at peak heating. Given the
limited areal coverage, will keep the PoPs at below 20 percent.


.LONG TERM...(Tuesday night through Sunday)
Issued at 310 AM EDT MON JUN 17 2024

Models are in good agreement for the pattern that will impact our
area during the long term period. Strong upper level high pressure
is expected to be centered over the Mid Atlantic states Tuesday
evening. Depending on the model, this high drifts northeast to
southern New England or just south on Wednesday, but maintains
strong ridging west-southwestward over the Ohio and Tennessee
valleys. Late in the week the upper level high/ridge shifts back
southward and weakens by the time it reaches somewhere between our
vicinity and the Southeast US coast. Resulting subsidence and warm
temps aloft will help to keep convection capped at least until late
in the long term period. During this time, large surface high
pressure centered offshore will ridge westward over VA early in the
period, and then also drift south. Our low level flow will emanate
from this high, not having trajectories over the warm gulf, and this
will keep dew points from being too excessive. In fact, dew points
are actually expected to go down a bit for Wednesday through Friday.
The limited low-level moisture will also help to reduce the
potential for thunderstorms.

As we move into the weekend, our low-level flow will have
trajectories coming from further south and this will bring dew
points back up. Models also hint at an upper trough moving across
the northern half of the country into the Great Lakes region late in
the weekend or early next week, which will likely push a cold front
east across the country and toward the Ohio Valley either Sunday or
Monday of next week. For now, will carry gradually increasing chance
generally 30 to 50) PoPs from Sunday morning through Sunday
overnight to reflect the uncertainty with the timing of the frontal
arrival and resulting showers and thunderstorms.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 710 AM EDT MON JUN 17 2024

VFR conditions are expected through much of the TAF period. Any
fog in the deeper sheltered river valleys will burn off through
13z, with scattered convection expected to occur beginning around
16z to 18z and ending by 00 to 02z. Will only carry VCTS at all
terminals for now, as confidence in the exact timing and location
remains low at this time. Winds will average around 5 kts or less
through the period, mainly from the south to southwest.
Statistical guidance suggests some fog potential at TAF sites
tonight, particularly at KLOZ, KSME, and KSJS, but the severity
and duration may be dependent on if the sites receive rain or not
this afternoon. Will leave any mention of fog out of the TAF at
this time given the low confidence.


&&

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

$$

SHORT TERM...GEOGERIAN
LONG TERM...CMC/HAL
AVIATION...CMC