851
FXUS63 KJKL 110620 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
220 AM EDT Sat May 11 2024

.KEY MESSAGES...

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

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

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

&&

.UPDATE...
Issued at 210 AM EDT SAT MAY 11 2024

Just a quick touch up to the forecast through morning, mainly
beefing up the valley fog and adding in the latest obs and trends
for the T/Td/Sky grids. These adjustments have been sent to the
NDFD and web servers along with a freshening of the zones, SAFs,
HWO, and also an SPS for areas of dense valley fog for much of the
area through 9 am.

UPDATE Issued at 1048 PM EDT FRI MAY 10 2024

A roughly once-in-a-generation geomagnetic storm event is
underway, resulting in a spectacular view of the aurora borealis
across eastern Kentucky currently. Note that you do not have to
looking north to see it as usual. There are reports of it being
seen currently in southern Florida.

As for the weather update as to what is occurring in the
troposphere, where most weather occurs, there is very little to no
change for the forecast through the remainder of the overnight.
Did blend in latest hourly observations with the forecast.

UPDATE Issued at 703 PM EDT FRI MAY 10 2024

There are a few isolated showers remaining over far eastern
Kentucky where PoPs are currently less than 15, but these showers
are expected to dissipate in the next 1 to 2 hours with the loss
of daytime heating. Also lowered forecast lows in many of the
sheltered valleys another degree or two for tonight. Otherwise,
the forecast is on track and no significant changes are needed.

&&

.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...(Sunday through Friday)
Issued at 420 PM EDT FRI MAY 10 2024

The 10/12z model suite is in good agreement Sunday morning showing
eastern Kentucky under rising heights as the upper level troughing
begins to lift away to the northeast. This will set the stage for
surface high pressure to crest over the Central Appalachians
later Sunday and Sunday night. A slow-moving filling low/trough
then tracks from the Central Plains on Sunday Night to over the
Ohio Valley late Tuesday and Tuesday night and off the Southern
New England shore on Wednesday night and Thursday. Under this
atmospheric undulation, a weak surface low will follow a similar
path from Kansas, directly across the Ohio Valley, and then off
the Mid-Atlantic coast. A weak cold front settles through our
area on Wednesday as that low departs. Surface high pressure and
shortwave ridging aloft return Wednesday night into Thursday
before yet another upper level trough and weak surface low
approach for Friday.

The sensible weather will feature dry periods interspersed with
rain chances as these systems pass. Initially, high pressure will
ensure seasonably cool and dry conditions on Sunday and Sunday
night. Expect temperatures to reach the lower to middle 70s on
Sunday followed by lows in the mid 40s to lower 50s on Sunday
night, all the while under clear to partly cloudy skies. This will
favor fog forming in the typical valley locations again on Sunday
night. Sunshine fades on Monday as clouds thicken from the
southwest. A few showers become possible by late in the
afternoon, primarily west of I-75. It will be milder with highs in
the mid 70s west to the lower 80s far east. A spell of numerous
to at times widespread mostly light to moderate shower activity
is then expected from Monday night into Wednesday. The
precipitation and cloud cover should lead to suppressed diurnal
temperature ranges, primarily lower to middle 70s during the day
and mid to upper 50s at night. A general 0.75 to 1.50 inches of
rain expected to fall across most of the area during this
timeframe. Some thunder is also possible but instability appears
very marginal. Clearer and drier weather then makes a brief
comeback Wednesday into Thursday under weak ridging before more
showers and possible thunderstorm chances return late Thursday
through Friday with another trough/weak surface low. High
temperatures warm back to around 80 degrees on Thursday under some
sunshine before thicker clouds hold highs in the 70s on Friday.
Nighttime lows remain mild, primarily in the 50 to 60 range.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 220 AM EDT SAT MAY 11 2024

VFR conditions are still holding at all sites at the start of the
forecast period. With mostly clear skies and light winds, though,
valley fog formation is kicking into overdrive, some of which
may impact the TAF sites with IFR or lower conditions for a time.
To account for this, a TEMPO group for fog down as low as 1SM
visibility was kept in the forecast along with low CIGs. Expect
west to west-southwest winds to increase through the morning
ahead of a cold front and upper disturbance that brings showers to
the area from late morning through much of the afternoon.
Sustained winds up to 12 kts will transition to a more
northwesterly direction with passage of that boundary in late
morning and afternoon - then diminishing after dark.

&&

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

$$

UPDATE...GREIF
SHORT TERM...SHARP
LONG TERM...GEERTSON
AVIATION...CMC/GREIF