Area Forecast Discussion Issued by NWS Jackson, KY
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 170938
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
538 AM EDT Sun Mar 17 2024
.KEY MESSAGES...
- A deep trough passing aloft brings a threat of some sprinkles
and flurries on Monday afternoon.
- Freezing conditions tonight and a hard freeze Monday night
could kill any cold sensitive vegetation that has emerged
prematurely due to early season warmth.
- Temperatures rebound back to near normal through mid-week, with
lower confidence in the next potential chance of precipitation
moving in towards the end of the work week.
&&
.SHORT TERM...-- Changed Discussion --
(Today through Monday)
Issued at 435 AM EDT SUN MAR 17 2024
08Z sfc analysis shows a broad area of low pressure northeast of
Kentucky and dragging a cold front through this part of the
state. This process is keeping a deck of clouds over much of the
area - especially south - along with southwest winds around 10 mph
just ahead of the boundary. In turn, this has limited the
radiational cooling most places and led to fairly uniform
temperatures in the upper 40s to lower 50s - though some low 40s
have been achieved in the most sheltered northeast valleys.
Meanwhile, dewpoints have fallen into the mid 30s to lower 40s
range - the resultant dewpoint depression and winds are keeping
most of the fog at bay this morning.
The models, and their individual ensemble suites, are still in
pretty good agreement aloft through the short term portion of the
forecast. They all depict fast zonal flow tilting more
southwesterly later today and more sharply tonight in response to
a deep trough extending through the southwest portion of the Ohio
Valley on the way to its digging through the Tennessee Valley by
Monday evening. This mid level flow will bring a stream of energy
down over Kentucky for Monday with accompanying height falls.
Given the still small model spread, have again favored the NBM as
the starting point for the forecast grids with mainly just some
terrain distinction added to the hourly temps and low temperatures
tonight and spotty PoP potential from the CAMs on Monday
afternoon.
Sensible weather will feature one last day of near normal
temperatures before colder air overwhelms the early warmth of
spring we have seen for the past week. Despite the weak CAA today,
enough sunshine will support readings climbing into the low to
mid 50s north and upper 50s to around 60 in the far southeast.
Although the clouds and continued sfc winds of 5 to 10 mph will
keep readings from dropping as far as they could, they still will
be below freezing most places - for the first time in quite a
while. Caution is urged for those who may have been lulled into
thoughts of an early spring and brought any plants outside or
where some early fruit tree blossoms have developed. Just know
that Monday night will be even colder. This is due to a further
surge of cold air into the area with another, mostly dry, cold
front keeping highs only in the 40s along with a potential for
some flurries and sprinkles during the afternoon - mainly for
eastern parts of the area.
The main adjustments to the NBM starting point were to again add
some terrain distinctions into low and hourly temperatures
tonight. PoPs were generally single digits from the NBM and kept
there through Monday evening.
.LONG TERM...(Monday night through Saturday)
Issued at 538 AM EDT SUN MAR 17 2024
A deep trough will start out just west of the Appalachians at the
beginning of the period, with a REX block hanging on across the
West. Through the middle of next week, the REX block breaks down,
with the southern stream closed low likely transitioning to an
open wave as it moves east over the southern Plains. The trough in
the East curls northeast with time, with cyclonic flow setup from
the Upper Midwest through the Ohio Valley, New England, and the
Mid-Atlantic. The southern stream short wave trough will continue
east through the end of the work week, with the operational GFS
still on the slower and more intense-side of the ensemble
envelope. The ECMWF remains quicker, more dampened, and further
southeast with the moisture. As such, there is still lower
confidence on precipitation chances from Thursday night through
Friday. Have maintained chance PoPs during this time frame, but
PoPs now only peak at around 40% for Friday, still trending down
overall from the past few days.
A cold air mass will be settled in across eastern Kentucky Monday
night, with high confidence of a hard freeze, as temperatures
settle into the low to mid 20s. Readings will rebound into the low
to mid 50s Tuesday, and then upper 50s to lower 60s for Wednesday.
A passing dry cold front will knock temperatures back down for
Thursday, with highs retreating to the low to mid 50s north, to
near 60 bordering Tennessee. Clouds will be on the increase during
the afternoon, with precipitation chances increasing from the
southwest Thursday night and Friday, before reducing to just slight
chances (20%) by Saturday. Temperatures will generally average
near normal through the rest of the period.-- End Changed Discussion --
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 150 AM EDT SUN MAR 17 2024
An approaching cold front has brought an increase in clouds and
eventually we will see ceilings lowering to the 5-6k feet agl
range into dawn. The front will clear the area by mid-morning,
followed by the clouds scattering out. Winds will be the biggest
impact from the front, though, with west southwest speeds of
around 10 kts, and gusts of 15 to 20 kts through much of the
night. The winds then shift to the northwest following FROPA,
remaining gusty for a few hours, before diminishing temporarily
around dawn. As better mixing ensues by the mid to late morning
hours, winds will become gusty once again, generally remaining
more out of the west to west northwest.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...GEOGERIAN
AVIATION...GEOGERIAN/GREIF