722
FXUS63 KJKL 150050
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
850 PM EDT Sun Jul 14 2024

.KEY MESSAGES...

- Hot and humid weather will bring heat indices around 100 degrees
  in many locations on Monday and Tuesday.

- The next significant chance of rain area wide arrives on
  Wednesday.

&&

.UPDATE...
Issued at 850 PM EDT SUN JUL 14 2024

Convection has waned over the past hour to hour and a half and
with sunset nearing, no additional development is expected
overnight. Hourly grids have been updated to account the outflow
dropping south and recent observations.

UPDATE Issued at 627 PM EDT SUN JUL 14 2024

Adjustments were made to hourly pops through around 01Z for
anticipated convective trends associated with the southward moving
outflow from stronger convection that occurred in OH and IN and
development near the Interstate 64 corridor. At this point, it
appears that the new development is not keeping up with the
outflow though some new development further south cannot be ruled
out through sunset or so. Other isolated convection that has not
been robust enough for lighting was occurring from Owsley County
east toward Martin and northern Pike counties. Outflow from this
activity may lead to isolated convection over the next couple of
hours for about another tier of counties south or so. Otherwise,
convection should wane within an hour or two after sunset.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 350 PM EDT SUN JUL 14 2024

Latest surface analysis continues to keep surface high pressure
across the area. However, due to the Upper Midwest being active
yesterday, the remaining convection has congealed into a southeast
migrating MCS that`s diving through Ohio.

For the remainder of the day, this MCS will continue to track
southeast toward the CWA but looks to clip the northernmost portions
of the CWA this evening. CAMs have been struggling with the MCS all
day but they do have the MCS dissipating in Southeastern Ohio as the
sun is setting. Locally, low-level west to northwesterly dry flow
has ushered in a dry air mass into the area which will stifle any
chances of widespread convection but can`t rule out a stray shower
north of the I-64 corridor this evening as the MCS approaches.
Overnight, lingering cloud liter could reduce chances of overnight
fog across the area but guidance really has been hammering on the
potential for fog. Therefore, opted to add valley fog through the
overnight; as well as, in areas where PoP exists.

Monday brings much of the same as today where convection in the
Upper Midwest traverses across much of the Great Lakes and Ohio
Valley into the CWA but like today, moisture is largely limited;
however, as flow turns a little bit more southwesterly, moisture
will increase slightly but not much to improve MCS maintenance. The
best PoP chances for Monday look to be mainly confined to the higher
terrain along the KY/VA/WV state line. Like today, Monday ends in
much of the same as cloud liter could limit the amount of fog that
could develop but again opted to put patch fog in the river valleys.

Otherwise, a persistence forecast exists for the period as a few
isolated showers or storms are forecast this evening and again
Monday afternoon/evening. Highs are forecast to be in the low to mid-
90s today with a record breaking high of 92 at KJKL. Monday`s highs
increase a few degrees as flow turns southwesterly with highs
climbing into the mid to upper-90s in a few places with heat indices
approaching 100 degrees. Overnight lows will remain mild across the
area too, as lows tonight will drop into the upper-60s to low-70s
and even warmer for Monday night.

.LONG TERM...(Tuesday through Sunday)
Issued at 427 PM EDT SUN JUL 14 2024

There is reasonably good model agreement during the long term
period. A large scale upper trough will be dropping southeast out of
Canada toward the Great Lakes and Ohio Valley Tuesday into
Wednesday. This will support a cold front which should eventually
make its way through Kentucky. However, models have been trending
slower with its progress, and its now looking like it will not enter
KY from the northwest until Wednesday night and not make it into TN
and VA until Thursday.

After meager wind fields on Monday, flow throughout the atmospheric
column will increase as the upper trough and its surface cold front
approach. This increases the potential for organized convection.
However, convection timing and placement will be greatly affected by
mesoscale factors including prior convection. It`s much too early to
have any real confidence in how this plays out. The NAM does show
the remnants of an MCS dying upon arrival in our north late Tuesday
morning, but forecast soundings look capped later during peak
heating. Will use a minimal 20% POP on Tuesday, but hold off
until Tuesday night for anything more. With so much uncertainty in
timing of any convective systems, will use a gradual uptick in
POPs until the front arrives. Peak 12 hr POP will be limited to
likely category at this point simply because of so much
uncertainty in timing. The probability of seeing rain from the
system as a whole at some point is higher.

The heart of the upper trough will begin to pull out to the
northeast by Thursday and the front will slow and then stall to our
south. The GFS and ECMWF both suggest it will be in close enough
proximity for at least a small threat of more precip in our southern
and southeastern counties Thursday night into Friday night. For the
weekend, the ECMWF is showing more support for the longer standing
GFS solution. This has a weak piece of the upper trough being left
behind over the lower and mid Mississippi Valley. The resulting mid-
upper level flow over our area becomes southwesterly, bringing deep
moisture with it, which favors precip during the weekend. Will use
chance POPs Saturday through Sunday, but this could eventually go
higher should the forecasted pattern hold.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 810 PM EDT SUN JUL 14 2024

Outside of initial convection near KSJS, VFR conditions are
forecast to dominate for the vast majority of the period. Fog
development tonight should generally affect valley locations
between about 04Z and 13Z. However, measurable rain fell near
KSYM and KSJS and it is possible MVFR or lower fog could affect
those areas as well, though confidence was not high enough to
include at this point. After any fog dissipates by about 13Z, some
convection may develop on Monday generally south of the TAF
sites. Outside of brief gusts with the initial southward moving
outflow, winds will be light and variable.

&&

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

$$

UPDATE...JP
SHORT TERM...VORST
LONG TERM...HAL
AVIATION...JP