895
FXUS63 KJKL 101922
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
322 PM EDT Fri May 10 2024

.KEY MESSAGES...

- Some showers and perhaps a storm or two are possible, at times,
  this afternoon and Saturday afternoon.

- Precipitation free weather is anticipated from Saturday night
  into Monday morning, before unsettled weather returns.

- Expect cooler temperatures through the weekend, with warming
  then returning.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 322 PM EDT FRI MAY 10 2024

Shortwave trough, embedded within broader troughiness across much of
the county, is clearing our region this afternoon. Shortwave ridging
will replace it briefly, providing equally brief clearing skies,
good enough for aurora watching, per Space Weather Prediction
Center`s severe geomagnetic storm warning! Not certain it will be
visible this far south, but worth a look. Relatively light winds and
these clear skies should promote valley fog formation late tonight.
In the wake of this morning`s cold front, expect low temperatures to
fall into the 40`s for most locations.

Saturday, another shortwave trough will cross the region,
reinforcing the cold front and bringing another night with lows in
the 40s Saturday night. Along the front, we`ll see another potential
for light rains, similar to today. Also similar to today, the
deepest moisture and thus potential for storms look to be in far
eastern KY. Forecast soundings west of Jackson show a fairly stout
inversion above about 700 mb, but it`s weaker east of Jackson.

.LONG TERM...(Saturday night through Thursday)
Issued at 520 AM EDT FRI MAY 10 2024

An upper level low is expected to in place over the eastern Great
Lakes region as the period begins within an upper level trough
extending from near the James Bay region to the mid Atlantic states
to the southeast U.S. coast, shortwave ridging from the western
Gulf of Mexico to portions of the Central Plains, another upper
level low upstream near the southwest portion of Hudson Bay and
finally an an upper low over the Four Corners vicinity. Futher
west, the axis of an upper level ridge should be near the west
coast of the Conus. At the surface, one frontal zone is expected
to be well south from portions of the western Atlantic across
south FL and the Gulf of Mexico to the Lower Rio Grand Valley to
southern NM while a front is expected to be departing to the
south and east of the Lower OH Valley at that point. A ridge of
sfc high pressure should extend from the Lower MS Valley to the
Arklatex region to the western Great Lakes at that point as well.
Further northwest on Friday night, a wavy frontal zone is expected
to extend west near or north of the US/Canadian border from sfc
low pressure near the Manitoba and Ontario border.

Saturday night to Sunday night, the axis of the upper level trough
should shift east of OH Valley and Appalachians with height rises
and shortwave ridging building in to end the weekend. The axis of
the upper level ridge should extend from the eastern Gulf of
Mexico across the Southeast and Lower OH by late Sunday night.
Meanwhile, the upper level low west and southwest of Hudson Bay
initially should move to the far norther Ontario/souther end of
Hudson Bay/James Bay region and the upper low further southwest
should move from the Four Corners region to the Central Plains. As
this occurs, sc high pressure will build across the Southeast and
OH and TN Valley region and the central and southern Appalachians
Saturday night and Sunday before shifting toward the eastern
seaboard. To the west and southwest, lee cyclogenesis over the
Plains should occur in advance of the upper level low moving into
the Plains with a sfc low moving east near the KS and OK border
area Saturday night to Sunday night with the boundary initially
over the Gulf of Mexico lifting north toward the Gulf coast
downstream of the sfc low. Further north, low pressure will track
from the Ontario and Manitoba border vicinity to the James
Bay/Ontario/Quebec border area while the trailing frontal zone
drops into the western Great Lakes and upper MS Valley to Dakotas
to MT to a sfc low in Alberta and then trailing into the Pacific
Northwest. Locally, PW should drop under the influence of ridging
to to around 0.5 inches per LREF mean Saturday night/early Sunday
before gradually increasing toward 0.6 inches per LREF mean by
late Sunday night. With high pressure building in, the potential
will be there for small to moderate ridge/valley splits and
typical valley fog this time of year.

Monday to Tuesday night, the upper level low will move from the
Central Conus/Central Plains vicinity to the OH Valley and TN
Valley region and approach the Appalachians. Guidance is in good
agreement that a shortwave moves from the Arklatex region and
across the region Monday to Monday evening and perhaps another
Monday night to early Tuesday in southeast flow aloft. Well north
of the area upper level low should continue to meander near the
James Bay to the Ontario and Quebec border with a trailing
shortwave trough moving across the Great Lakes Monday to Monday
night. At the sfc, low pressure should track from the Central
Conus to the mid MS and Lower OH Valleys through Tuesday and then
toward the eastern seaboard on Tuesday night. Meanwhile the
shortwave crossing the Great Lakes should send the frontal zone
south and southeast of the Great Lakes and into the Northeast to
OH Valley to Central Conus as a sfc low mores to the Lower St
Lawrence Valley and Maritimes vicinity. Moisture will be
transported into the OH Valley and Appalachian region with PW per
the LREF mean climbing to about 1 to 1.2 inches by Monday evening
and peaking about 1.2 to 1.3 ahead of the boundary sagging into
the area Tuesday to Tuesday evening. After a dry start to the
long term period, unsettled weather will return by late Monday
into Monday night and continue into Tuesday night as one or more
shortwaves cross the area and sfc low pressure tracks into and
across the Commonwealth.

Wednesday to Thursday, the OH Valley/Appalachian region upper
level low/trough should gradually shift east to the eastern
seaboard with guidance suggesting that shortwave ridging quickly
shifts east across portions of the Southeast Conus, TN and OH
valleys and portions of the Appalachians to Great Lakes to end
the period ahead of the upper level troughing evolving from the
western Conus into the Central Conus with this trough axis
approaching the MS Valley toward the end of the period. A couple
of shortwaves could work into the OH and TN Valleys late in the
period once the ridge axis moves east. At the sfc, the frontal
zone should settle south of eastern KY and much of Southern
Appalachian region Wednesday night to Thursday with a ridge of
sfc high pressure shifting across the area Wednesday to Wednesday
night. Further west, low pressure should evolve over the Central
Conus/Plains and approach the MS Valley on Thursday. PW over the
region should briefly drop below 1 inch under the influence of
ridging behind the sagging front before increasing again on
Thursday about 1 to 1.2 inches per LREF mean. A brief lull in
chances for precipitation should occur by late Wednesday into
Wednesday night and perhaps linger into early Thursday. Chances
will however increase as the ridge shifts east and the next
series of disturbances and low pressure system approaches to end
the period.

Temperatures begin the period below normal, before climbing to
around 5 degrees above normal on Monday with high pressure
dominating. Nearer to normal high temperatures are expected with
more in the way of clouds for Tuesday to Wednesday. Temperatures
may climb to nearly 5 degrees above normal to end the period ahead
of the next approaching series of systems on Thursday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 112 PM EDT FRI MAY 10 2024

A cold front has cleared the region early this afternoon, but post
frontal cloud cover has lingered, with ceilings in a few spots
briefly IFR. Still seeing a few showers, but the back edge has
just cleared KSYM and any further activity should be limited to
KJKL/KSJS before ending in the next few hours. VFR conditions
should be at all sites before the evening hours. With partly
cloudy skies and light winds, expect some valley fog formation,
but no concerns at TAF sites. Expect winds to pick up from the
west, ahead of the next disturbance to cross the region. Rain
chances return early Saturday afternoon.

&&

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

$$

SHORT TERM...SHARP
LONG TERM...JP
AVIATION...SHARP