Area Forecast Discussion Issued by NWS Jackson, KY
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000
FXUS63 KJKL 252131
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
531 PM EDT Mon Mar 25 2024
.KEY MESSAGES...
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- A critically dry air mass and an increase in southeast downslope
winds will result in increased fire danger through late this
evening.
- Above normal temperatures return today before another round of
rainfall late tonight and Tuesday. A few thunderstorms will be
possible across the area late tonight into Tuesday morning.
- Temperatures cool to within a few degrees of normal from Tuesday
through Friday, with the threat for sub-freezing temperatures
returning for many valley locations by Thursday night.
- PoPs start to creep back in from the northwest this weekend,
with temperatures returning to around 10 degrees above normal.-- End Changed Discussion --
&&
.SHORT TERM...-- Changed Discussion --
(This evening through Tuesday night)
Issued at 447 PM EDT MON MAR 25 2024
Presently the forecast area is under the regime of surface high
pressure ahead of an approaching surface low. One low exists over
the Central Plains while another exists across the Deep South. The
Central Plains low will eject northeast into the Great Lakes and
drag a cold front through the region. A deep column of dry air
exists across the area with the surface high present. This has
allowed for dewpoints to plummet into the upper-teens with RHs in
the lower teens this afternoon. The low dewpoints coupled with
strong winds will allow for increased fire weather dangers. While
the area will remain below RFW criteria, the dry weather and gusty
wind will allow for a fire to grow out of control. Also, winds will
continue to remain below wind advisory criteria as a strong
inversion is in place and there`s no feature to mix those winds down
to the surface. However, gusts to 35 mph isn`t out of the question
later tonight and into early Tuesday afternoon. Locally higher gusts
will be possible mainly across the high terrain along the Virginia
border.
As the aforementioned surface low ejects into the Great Lakes
tonight; the associated cold front will gradually move into the
Commonwealth and approach the JKL CWA after 3 AM. However, due to
widespread dry air in place, large scale evaporation will occur and
until the column saturates, rain accumulations will be relegated to
sprinkles or light rain. Along the front, thunderstorms are
possible. Today`s CAM guidance has continued to come in a little bit
heavier on the forecast CAPE ahead of the front. The best CAPE
gradient looks to be along and west of the I-75 corridor and this is
where the best chances for thunderstorms exist. Not looking at any
severe storms but a rumble of thunder or two is possible. Showers
will increase in coverage through the overnight as the front crosses
through the CWA. Showers will begin to decrease in coverage from
west to east early Tuesday afternoon with only lingering upslope
showers in place for the end of the period. Overall QPF amounts have
come up a little bit in this afternoon`s forecast package but
widespread 0.20" to 0.30" of rainfall with 0.50" along the Hal
Rogers Parkway is expected. Locally higher amount is possible where
thunderstorm activity is confined.
Overall, the forecast period will be highlighted by warm, dry and
windy conditions transitioning into a weak cold front that`ll bring
wetting rain and isolated thunderstorms through the end of the
period. High temperatures in the low to mid-70s is expected today
with overnight lows only dropping into the low-50s. As expected with
the rain, Tuesday will be cooler with highs only topping out in the
lower-60s and falling temperatures overnight Wednesday as the front
exits the region.
.LONG TERM...(Wednesday through Monday)
Issued at 531 PM EDT MON MAR 25 2024
A deeper trough will start out across the center of the CONUS,
with a stout closed low swinging through the Upper Midwest/western
Great Lakes region. This feature will curl northeast into Ontario
through Thursday, with the long wave trough axis shifting east,
clearing the central and southern Appalachians by Thursday
evening, with surface high pressure building in from the west.
Upstream, modest ridging will move from the Rockies to the Plains,
before dampening even further as it crosses the Mississippi
Valley. Mainly zonal flow will then be found east of the
Mississippi River by this weekend and into early next week, as a
positively tilted trough in more of a split-flow regime takes
shape out west and gradually moves southeast with time. At the
surface, a baroclinic zone will gradually develop from the Midwest
through the Ohio Valley by this weekend and early next week. Model
agreement is good through late in the work week, but then declines
somewhat towards the end of the period, as details associated with
the nearing frontal boundary to our northwest becomes lower
confidence.
Sensible weather features diminishing slight chance PoPs across
far eastern Kentucky through the day on Wednesday, as the cold
front pulls further away. The frontal timing will yield a good
gradient of temperatures across the area, with locations further
east perhaps nearing 70 degrees, while sites across the Bluegrass
will remain near or just below 60 degrees. The trough axis will
remain to our west Wednesday night, with at least some lingering
clouds combatting the cool air advection across our southeast,
with most places staying above freezing. Locations towards the
Bluegrass as well as along and west of I-75 stand a better chance
of nearing the freezing mark. High pressure will build in more
solidly Thursday into Thursday night, with drier air likely to mix
down some dew points in the mid 20s during peak heating...closer
to the 10th percentile of the blended guidance. This will setup a
colder night overall for Thursday night, with the typically colder
valley sites dipping below 30 degrees.
Temperatures will gradually modify through the rest of the
period, as more of a return flow ensues. Bouts of 850 mb moisture
transport will then advect in from the west southwest this
weekend and especially early next week, as a frontal boundary
generally sags closer to the vicinity of the area. Slight chance
PoPs (20%) will return from the northwest as early as late Friday
night. Small chance PoPs (20-30%) will then continue to threaten
a larger portion of the forecast area through this weekend, with
even a threat of some thunderstorms at times. By early next week,
PoPs increase to good chance (40-60%), as deeper moisture and
forcing arrive, with front drawing closer. Temperatures will
trend back to around 10 degrees above normal towards the end of
the period.-- End Changed Discussion --
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 137 PM EDT MON MAR 25 2024
VFR conditions are expected to prevail through the TAF period
except for a few hours toward the end of the period.
Southeasterly winds sustained 10 knots with gusts 15 to 20 knots
are expected through the period as the area is ahead of a cold
front. Around 01Z, LLWS will develop and persist through about
14Z. During this time frame, showers and isolated storms will
increase in coverage and persist through the remainder of the TAF
period. CIGS may lower enough to flirt with MVFR; however, kept
the TAFs low end VFR for the last couple of hours of the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...VORST
LONG TERM...GEOGERIAN
AVIATION...VORST