481
FXUS63 KJKL 240040 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
840 PM EDT Thu May 23 2024

.KEY MESSAGES...

- Showers and thunderstorms are expected from time to time through
  the middle of next week, especially during the afternoon and
  early evening hours.

- A few storms could be strong to severe though the rest of the
  evening.

- There is a potential for severe thunderstorms again on Sunday,
  with damaging winds and large hail being the primary threats.

&&

.UPDATE...
Issued at 840 PM EDT THU MAY 23 2024

00Z sfc analysis shows a meso-high working through eastern
Kentucky south of a stalled frontal boundary. The latest MCS is
starting to rain itself out over the CWA this evening but a few
strong to severe storms will be possible for another hour or so
out ahead of the main storm cluster. For this reason, and in
coordination with MRX and SPC, we have extended the severe watch
until 10 pm but dropped it generally west of I-75 where conditions
have stabilized. Temperatures currently vary from the lower 60s
in the recently rain cooled areas to the low 70s in the far east.
Dewpoints remain elevated in the mid to upper 60s most places amid
mostly light winds away from any thunderstorms. Have updated the
forecast mainly to fine tune the PoPs through the rest of the
night per radar and CAMs trends. Did also include the current obs
and tendencies for the T/Td/Sky grids. Additionally, the fog was
hit hard late tonight with clearing and thinning of the mid and
high clouds anticipated. These adjustments have been sent to the
NDFD and web servers along with a freshening of the zones, SAFs,
and HWO - primarily to address the extension of the watch.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 455 PM EDT THU MAY 23 2024

A stalled, ill-defined frontal boundary is located just north of
KY late this afternoon. On the south side of the front, our air
mass is mild and fairly humid, with dew points running in the 60s.
Temperatures are running in the 70s, being held back during the
day by earlier clouds and precip. Never the less, it`s enough to
support another round of thunderstorms heading in from central KY,
helped along by a weak mid/upper level trough. Modest shear is
also present, and marginally severe storms can`t be ruled out with
the instability/shear combo, with Severe Thunderstorm Watch 293
continuing until 8 PM for our western counties.

The convection is expected to weaken as it exits east tonight.
Clouds will try to break up as mid-upper levels dry, but
radiational cooling after the precip will probably result in fog
and low clouds developing and lasting into Friday morning.

The fog and low clouds will dry up by mid day and sun/heating will
cause destabilization again. However, the currently stalled
frontal boundary will lift north away from the region as a warm
front, and the only mid/upper level wave to be seen in models
should have its main influence to our south in the afternoon and
evening. That being the case, despite instability, the probability
of rain appears to be relatively low Friday and Friday night due
to lack of support, and nothing more than a small chance (30%) has
been used.

.LONG TERM...(Saturday through Thursday)
Issued at 610 PM EDT THU MAY 23 2024

The models are in general agreement with an unsettled pattern to
remain across the Ohio and Tennessee valleys through early next
week. Above normal temperatures, higher humidity, and daily
rain chances will be on tap. A more decisive cold front will move
through by the middle of next week, with cooler and drier air
filtering into the region. Short wave ridging will move in over
eastern Kentucky on Saturday; however, with a surface cold front
still in the general vicinity, at least a 50% chance of showers
and storms are possible. Did undercut the blended guidance a bit
here, as the short wave ridging has been consistently showing up in
the guidance for the past few days.

Meanwhile, deeper mid and upper level energy will shift east from
the Rockies through the Plains, likely cutting off as the main
short wave curls northeast through the Upper Midwest/western
Great Lakes region by Sunday. This will result in a stronger
surface low genning up across the southern Plains and move
through the middle Mississippi Valley and into the Great Lakes.
There is some uncertainty as to the position of the associated
warm front, which would branch east southeast somewhere near the
Ohio River on Sunday, with eastern Kentucky more planted within
the warm sector. Given the stronger system and likely increased
coupled effective shear and instability in place, a severe weather
threat exists, with all hazards a possibility, although specifics
still remain lower confidence at this time. Depending on how much
of a break portions of our area see as far as rainfall leading
into this next uptick, at least a renewed minor flooding threat
would also accompany the additional severe weather hazards. PoPs
will peak in the 60-90% range Sunday night and Monday, as the cold
front approaches and eventually progresses through the region.

At least chance PoPs (20-40%) linger through Wednesday,
as broad cyclonic flow remains in place across the northeastern
quadrant of the CONUS, although they will be decreasing each day,
as moisture gradually decreases. 500 mb heights make a better
recovery by Thursday, with dry weather finally returning. Above
normal temperatures will reign through Monday, with highs ranging
from the upper 70s to mid 80s, with lows mainly in the low to mid
60s. Cooler air will then move in from Tuesday through Thursday,
with highs retreating to the mid 70s, and lows mainly in the 50s,
with a few upper 40s possible in the typically colder valleys by
early Thursday morning.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 815 PM EDT THU MAY 23 2024

A mix of aviation conditions exist across the area as we are in
the midst of this evening`s dying MCS. The worst of the conditions
are down to IFR with storms while a few VFR spots remain. Have
carried a fair number of tempos in the terminal forecast for the
the next few hours to cover those poor conditions with any storm.
Once the precipitation dies out toward midnight, fog and low
clouds are expected to develop bringing IFR or worse conditions
for most places. VFR conditions are then expected to return mid to
late Friday morning. Winds will be generally light and variable
through the period - away from any storms.

&&

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

$$

UPDATE...GREIF
SHORT TERM...HAL
LONG TERM...GEOGERIAN
AVIATION...HAL/GREIF