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195
FXUS63 KJKL 010315 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1115 PM EDT Fri May 31 2024

.KEY MESSAGES...

- Dry weather can be expected through Saturday morning. The next
  system will then begin to impact the region starting late
  Saturday and continuing into Sunday.

- Sensible weather conditions will become warmer and more humid
  with a potential of showers and thunderstorms continuing into
  the new work week.

&&

.UPDATE...
-- Changed Discussion --
Issued at 1115 PM EDT FRI MAY 31 2024

Just a quick update to the forecast mainly to add in the latest
obs and trends for the T/Td/Sky grids along with a tweaking of the
overnight temperatures and lows fine-tuning the ridge to valley
split. These minor adjustments have been sent to the NDFD and web
servers along with a freshening of the zones and SAFs.

UPDATE Issued at 735 PM EDT FRI MAY 31 2024

23Z sfc analysis shows high pressure off to the east and holding
on for one more evening over eastern Kentucky. Meanwhile, low
pressure continues to work towards eastern Kentucky from the west
with some leading high clouds moving into the area from central
Kentucky. Most of the fair weather cumulus has cleared out with
the approach of sunset. This will likely allow for a period of
decent radiational cooling yielding a moderate ridge to valley
temperature split through the night along with a potential for
fog in the river valleys late tonight into dawn, Saturday.
Currently temperatures vary from the upper 60s in some sheltered
eastern valleys to the low and mid 70s elsewhere. Meanwhile, amid
generally light and variable winds, dewpoints range from the mid
and upper 40s north to the low and mid 50s south. Have updated the
forecast mainly to add in the latest obs and trends for the
T/Td/Sky grids. These minor adjustments have been sent to the NDFD
and web servers.

UPDATE Issued at 1057 AM EDT FRI MAY 31 2024

The late morning update raises Sky grids through the short term
as high-level cloud cover is proving to be thicker than initially
forecast, enough so to partially obscure the sun. Besides raising
the sky cover in the grids, changes were minimal. Blended in
latest observations to the forecast.

UPDATE Issued at 703 AM EDT FRI MAY 31 2024

The forecast is on track. Early morning obs are blended into the
forecast without substantive changes.
-- End Changed Discussion --

&&

.SHORT TERM...(Today through Saturday)
Issued at 308 PM EDT FRI MAY 31 2024

Northerly flow aloft gives way to amplified upper ridging over the
area by this evening, which then gives way to southerly flow aloft
and weak warm advection overnight tonight. A weak slow-moving
shortwave disturbance then moves east up the Ohio River Valley
Saturday into Saturday night bringing increasing moisture and
meager instability.

With upper ridging moving over the area tonight expect another night
of good to excellent radiational cooling conditions, though high
clouds could disrupt that somewhat. Nevertheless, COOP MOS suggests
many sheltered valley locations will fall down well into the 40s,
with the potential for lower 40s at the coldest locations, with
lower to mid 50s on the ridgetops as warm advection begins to
increase and amplify ridge-valley temperature differences.

Warm advection begins to increase in the early morning hours
Saturday, with thickening cloud cover and moisture arriving from
west to east through the daytime hours. Instability is
significantly lacking so lowered the PotThunder grids about 5
percent, enough to keep any mention of thunderstorms out of the
forecast through early Saturday evening. With thicker cloud cover
beginning in the morning in the southwest and not reaching the far
eastern areas until later in the afternoon, highs in the west,
and southwest especially, are only expected to reach the mid 70s,
while highs in the lower to mid 80s are expected in the Big Sandy
basin.

The model consensus continues to delay arrival of precipitation into
and across the forecast area until later in the day Saturday.
Nevertheless, shower and thunderstorm chances increase Saturday
evening into the overnight, especially western and northern parts of
the forecast area, with highest QPF approaching 0.50-0.75 inches
along and north of Interstate 64 and lowest QPF of 0.10" or less
across the southeastern third of the forecast area. With increased
cloud cover and moisture, lows Saturday night look to be warmer
in the mid 50s to around 60 degrees.

.LONG TERM...(Saturday night through Thursday)
Issued at 323 PM EDT FRI MAY 31 2024

An active weather pattern is anticipated across the CONUS in the
extended, as a series of low pressure systems are forecast to move
through. The upper level pattern will feature weak ridging in place
just offshore of the southeastern US. This ridge will quickly
retreat out to sea, as a short wave makes its way eastward through
Ohio and Tennessee Valleys. A broad, flattened ridge will move in
behind the departing trough Sunday night into Monday, and will give
us a breif respite from the numerous showers and scattered storms we
will likely experience around the area on Sunday. This ridge may be
strong and persistent enough to keep the weather dry or mostly dry
Sunday night through Monday morning. After that, another area of low
pressure will begin taking shape over the Great Plains, but will be
slow to make a strong eastward push, as the surface ridge holds
fast. We could see enough instability and heating on Monday to allow
for diurnally driven convection, but likely on isolated to scattered
stuff based on the latest model data. As the eastern ridge finally
begins to weaken Monday night into Tuesday, it will drift off to the
east, as the Plains low finally has enough momentum to make a firm
eastward push. A cold front associated with the central CONUS low
will move through the region Tuesday and Tuesday night, and will get
hung over the area through mid-week, as its parent trough
intensifies over southern Canada, and sort of sits and spins up
there for a bit. The best chances for showers and storms look to be
during the afternoon and evening hours Tuesday and Wednesday, as the
front meanders about nearby. By Thursday, the front and its parent
trough should finally make a solid eastward push, as the upper
trough begins move off to east across Canada. We should see numerous
showers and storms move through the area late Thursday, as the front
finally moves through. The rain should steadily taper off Thursday
evening and night, after the front has moved by. Enough moisture and
lift may be present on the backside of the departing upper trough to
allow scattered showers and perhaps an isolated storm to linger over
the area on Friday.

Temperatures look to be a bit above normal on average, with daytime
highs maxing out in the upper 70s to mid 80s most days, and nightly
lows falling into the upper 50s to upper 60s through the period. We
don`t anticipate any threats of severe weather or flooding in the
extended at this time.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 750 PM EDT FRI MAY 31 2024

VFR conditions are expected through most of the period. The only
exception will be localized valley fog during the early morning
hours on Saturday, but the TAF sites will not be impacted. Light
and variable winds tonight will become southerly at 5 to 9 kts
after around 14Z. Look for some Lower clouds and shower chances
to start to move into the western aerodromes of KSME and KLOZ,
after 18Z.

&&

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

$$

UPDATE...GREIF
SHORT TERM...CMC
LONG TERM...AR
AVIATION...CMC/GREIF