National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KJKL 131946
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
346 PM EDT Sat Apr 13 2024

.KEY MESSAGES...

- A passing disturbance may bring isolated showers and storms to
  areas along and east of the Mountain Parkway Sunday evening.

- Well above normal high temperatures will affect the area from
  Sunday through Thursday, peaking in the upper 70s to mid 80s
  each day, or 10 to 15 degrees above normal.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 313 PM EDT SAT APR 13 2024

As of 15Z surface analysis, high pressure is situated across the
Deep South and this will remain in place through the period. Also,
there`s a warm front extending, from a surface low in southern
Canada, southeast across the central CONUS. Locally, mostly clear
skies are in place with warming temperatures/

Through the day today, high pressure will remain in place and the
warm front, mentioned above, will lift through the region. A pretty
quiet day is expected aside from breezy northwest winds. Winds will
diminish toward the overnight but will shift to the southwest as the
warm front lifts through the region. Behind this front, warmer
temperatures and height rises are expected overnight and will persist
through the remainder of the period.

Through the overnight, the little Clipper moving through southern
Canada will dive southeast through the Great Lakes into the Mid-
Atlantic. This will drag a weak cold front to the door step of the
CWA for Sunday afternoon. HiRes CAMS are hinting at a line of
showers and thunderstorms diving south but how far south is a little
hazy as the front looks to stall out along the Ohio River.
Therefore, opted to keep light PoP across northern portions of the
CWA through the end of the forecast period. Otherwise, above average
temperatures are expected to be in place with mostly dry weather for
the duration of the forecast period.

.LONG TERM...(Sunday night through Friday)
Issued at 406 AM EDT SAT APR 13 2024

The guidance, including ensembles, is in good agreement on a mid-
level wave passing through portions of the Ohio Valley and a
weakening cold front moving through the Upper Ohio Valley. The NBM
is keeping at least slight to chance PoPs in the 15–40 percent
range, with the best chances of showers and isolated thunderstorms
in the far east and northeast portions of Kentucky. It looks like
the best chances of PoPs will be in the evening before steep mid-
level lapse rates decrease. Then Monday, the weakening nearby
cold front and ample instability (MUCAPE around 1000 J/kg) could
lead to more showers and an isolated thunderstorm. The biggest
issue I see here is mid-level height rises in response to a mid-
level closed low across the Rockies, and a capping inversion could
keep convection at bay. This is leading to disagreement in the
guidance on coverage of convection Monday, and we could see this
backing off more as we get closer to the time frame if these
height rises hold. As a matter of fact, it is interesting to look
at a medium-range CAM like C-SHiELD showing no convection at all
on Monday. Right now, it looks like outside of convection we would
see a mostly sunny to partly cloudy day leading to above-normal
highs, as afternoon maximum temperatures are forecast to climb
into the upper 70s to lower 80s.

On Monday night, any convection that is left over should die off
as we lose heating and any steeper mid-level lapse rates. This is
as we remain in shortwave ridging through the night, and wherever
the left-over boundary is, it will lift northward as a warm
front. This as Lee Side low becomes more vertically stacked across
the Central Plains, with upper low deepening and ejecting
northeast toward the Great Lakes. While we could see an isolated
shower or thunderstorm Tuesday, mainly north of the Mountain
Parkway, it will be largely dry. This, coupled with strong warm
air advection, will lead to another warm day, with afternoon highs
forecast to climb into the upper 70s and lower 80s. This
strengthening system will eject northeast into the Great Lakes,
with a cold front advancing toward the Ohio Valley Tuesday night
into Wednesday. This is where the depth of the low and timing
differences begin to show up in the guidance, and there is
evidence of this in the NBM PoPs only coming in around the 50–70
percent range on Wednesday. In terms of severe weather, it would
appear the better signals show up for the western and central
parts of the state, but this will vary depending on the timing of
the cold front. Even so, we can`t completely rule out some
stronger storms on Wednesday evening, particularly if this is a
more organized line of convection, but as is often the case,
timing is poor here for more robust instability despite ample
shear.

This cold front will push through the area Wednesday night and
become more ill-defined as it moves into the Tennessee Valley.
This will probably lead to a period of drier weather sometime
later on Wednesday night into part of Thursday. Then yet another
shortwave and cold front dive southward into the Ohio Valley,
renewing chances of what will be more in the way of rain showers.
This as flow becomes more westerly to even closer to
northwesterly, keeping instability bottled up in the southeast
states. However, there appears to be a fair amount of disagreement
on the timing and location of this next system, and certainly
good evidence is seen in the spread seen among the ensemble
guidance for afternoon highs on Thursday. Right now, showers will
linger into Friday as cooler air advects in, with afternoon highs
on Friday climbing into the low to mid-60s, which is closer to
average.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 137 PM EDT SAT APR 13 2024

VFR conditions are expected to prevail through the TAF period as
surface high pressure continues to build into the region. Winds
will begin to pick up from the northwest with sustained winds
around 10 knots and gusts to around 20 knots. Winds will diminish
toward sunset but southwesterly LLWS will develop toward
08Z/Sunday and persist through around 14Z before winds increase
out of the southwest to end the TAF period.

&&

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

$$

SHORT TERM...VORST
LONG TERM...DJ
AVIATION...VORST