Area Forecast Discussion Issued by NWS Jackson, KY
000
FXUS63 KJKL 152035
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
435 PM EDT Fri Mar 15 2024
.KEY MESSAGES...
- Temperatures will remain about 5 to 10 degrees above normal
through Saturday night.
- A cold front sags south through this evening with lingering
showers and any thunderstorms diminishing.
- A deeper passing system aloft brings a threat of some rain/snow
showers on Monday.
- Hard freeze conditions Monday night could kill any cold
sensitive vegetation that has emerged prematurely due to early
season warmth.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 435 PM EDT FRI MAR 15 2024
Late this afternoon, the axis of a shortwave trough extended from
near the Ontario and Quebec border to the Central Great Lakes
while a more southern shortwave was moving across the Lower OH
Valley region. Further northwest an upper level low was working
across Manitoba with an associated shortwave trough to the south
toward the US/Canadian border. A sfc low associated with this
system was tracking from Manitoba into portions of Ontario with a
cold front trialing southwest to near the ND and MT border with
Canada. Closer to home, a surface cold front continues to sag
south and southeast across eastern KY and was located from near
Charleston WV to JKL to Rockcastle County. Showers were most
prevalent near and south of this boundary although some showers
were located near the front aloft further to the north. Meanwhile,
a sfc ridge of high pressure was centered over the Central Plains
and extended toward portions of the MS Valley.
This evening and tonight, the shortwave moving across the OH
Valley will cross eastern KY through tis evening, moving east of
the area by late this evening followed by a more moisture starved
shortwave overnight. In advance of this, the cold front that is
sagging south and southeast across eastern KY should sag into VA
and TN by mid to late this evening with the sfc ridge of high
pressure building east into the OH Valley behind it. The axis of
this ridge of high pressure will sag south of eastern KY through
the day on Saturday. This will occur in advance of the upper low
moving from Manitoba into Ontario and the trailing shortwave
trough working across the upper MS Valley and into the Great Lakes
region and the associated cold front that should drop southeast
of the western and central Great Lakes through the day on
Saturday. The upper low is progged to move to Quebec through the
end of the period while the trailing shortwave trough rotates
across the Great Lakes and into the OH Valley. This will help push
the cold front across the Commonwealth on Saturday night. A much
colder airmass than what has been experienced recently will arrive
behind the front as the period end with 850 mb temperatures
forecast to drop to the 0C to 5C range at that point with further
cooling and cold air advection continuing into the start of the
long term period.
Limited instability remains across the region at present with
MUCAPE analyzed in the the 100 to 250 J/kg range with effective
shear in the 20 to 25 KT range though these values will be
diminishing over the next few hours. Lighting has not been
detected across the region so far this afternoon, however, with
the limited instability remaining, an isolated storm or too
cannot be ruled out ahead of the boundary. However, mainly just
showers are expected with chances diminishing from northwest to
southeast through this evening. Precipitation free weather will
follow for the balance of the near term period.
Although the airmass behind the front crossing the region at this
time will cooler than what was experienced earlier this week,
temperatures will remain a few degrees above normal, by about five
degrees through Saturday. Mild weather will above normal
temperatures will persist into Saturday night ahead of the
secondary boundary.
.LONG TERM...(Saturday night through Thursday)
Issued at 355 AM EDT FRI MAR 15 2024
Surface high pressure will be in place to start the period. Upper-
level zonal flow will keep moderate temperatures across the area.
Overnight lows Saturday night will be in the low to mid-40s with d
anytime highs for Sunday expected to be in the upper-50s to lower-
60s. A dry cold front will cross through the area Sunday afternoon.
This will usher colder temperatures back into the area with below
average temperatures expected to persist through the early part of
next week. The upper-level trough responsible for the cold front is
still forecast to pivot toward the CWA and bring the potential for
rain/snow mix to the region for Monday afternoon. The areas mostly
likely going to see PoP will be along and north of the Mountain
Parkway. Models continue to hint at another chance of precipitation
on Tuesday as another weak cold front will move through the region
Tuesday afternoon. Surface high pressure returns for the middle of
next week with temperatures gradually increasing through the week.
The active period continues as models bring another system through
the region for the end of the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 230 PM EDT FRI MAR 15 2024
Near and in advance of a southward sagging cold front, reductions
to MVFR and lower in some areas at briefly during showers were
observed at issuance time. MVFR ceilings will spread spread
southeast across the region through 23Z with further reductions
to IFR near the boundary itself. Ahead of the boundary isolated
thunderstorms cannot be completely ruled out. Reductions should
continue after 0Z, though drier air moving in behind the front
should result to improvements from north to south generally north
of the Mountain Parkway back to VFR between 00Z and 06Z. Reduced
ceilings will persist further south as late as 15Z in some areas.
VFR should prevail areawide to end the period. Some fog
development may also occur after 06Z and dissipate through 14Z.
Winds will be southwest to west ahead of the boundary and become
northwest to north behind it through 23Z. Speeds should generally
be 10KT or less. North winds should prevail through 06Z before
becoming light and variable late. Winds should then become more
weest to southwest late in the period as another boundary begins
to approach the Commonwealth.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...VORST
AVIATION...JP