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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 220721
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
321 AM EDT Mon Apr 22 2024

.KEY MESSAGES...

- Fair weather lasts at least into Tuesday afternoon.

- Frost is expected in most places by dawn on Monday, and
  possibly again by dawn on Tuesday in many valley locations.

- A moisture-starved cold front is forecast to pass Tuesday night
  into Wednesday morning, bringing a round of light rain mainly
  for northern locations.

- Below normal temperatures return from Wednesday into Thursday
  morning before a warm front arrives on Friday and ushers in
  well above normal temperatures for the weekend.

&&

.UPDATE...
Issued at 835 PM EDT SUN APR 21 2024

Hourly grids were freshened up based on radar and satellite
trends. This led to no substantial changes at this time.

&&

.SHORT TERM...
-- Changed Discussion --
(This evening through Monday night)
Issued at 416 PM EDT SUN APR 21 2024

A very quiet short term period is in store, with temperatures
being the only concern. Surface high pressure centered near OK
late today is ridging northeast over the Ohio Valley, while a
progressive upper level trough approaches us from the northwest.
The surface high is supplying a cool and dry air mass, and
mid/high clouds have largely departed to the east in association
with a smaller wave caught in the flow ahead of the main upper
level trough. That will leave us with clearing skies this
evening, with diurnal cu drying up. Good radiating conditions
should result in a bigger drop in temperatures tonight, with frost
for most locations. Steep low level lapse rates may initially
inhibit decoupling, but think that surface cooling will eventually
win out.

Sunshine, ridging aloft passing over, and a lack of cold air
advection on Monday will allow for a bit warmer readings than on
Sunday, but will still be cool enough to allow for another frost
potential with diurnal cooling on Monday night. A return of warm
air advection will keep ridges milder on Monday night, but valleys
should readily decouple from the flow and chill. The GFS is
suggesting high clouds will show up during the night ahead of the
next system approaching from the Midwest. This could impact
radiating to some extent. All that said, frost shouldn`t be quite
as widespread, but the eventual need for an advisory can`t be
ruled out.

.LONG TERM...(Tuesday night through Sunday)
Issued at 321 AM EDT MON APR 22 2024

To start the period, a cold front extending from a surface low
moving across the Great Lakes will slowly be diving southeast into
the CWA. Showers and thunderstorms are forecast to increase ahead of
the front but due a widespread lack of instability due to the timing
of the front, severe weather looks to be limited. Models have
increased QPF slightly across the Bluegrass counties which through
FROPA are forecast to see about 0.30" with decreasing amounts moving
southward toward the TN/KY state line.

High pressure builds back into the region for late Wednesday and
persists through early Friday morning. Frost may be possible
Thursday morning as northwesterly flow and clear skies will allow
for temperatures to fall across the area. The more sheltered eastern
valleys are the most likely to see the increase frost potential.
Models have backed off a little bit on the previously mentioned
active forecast for the end of the period. The GFS continues to keep
the pattern active while the ECMWF opts to keep the area mainly dry.
They do agree on temperatures climbing into the upper-70s to low 80s
but differ on how several perturbations will move through the area.
However, due to the differences in model agreement, opted to go
with the NBM solution that favors 20-40% chance of showers and
storms through the end of the period.

Overall, a relatively active and cool start to the forecast period
is expected but toward the end of next week, model differences begin
to arise leading to a messy solution. However, PoP chances do seem
possible through the end of the period with temperatures becoming
more seasonal by the start of the weekend.
-- End Changed Discussion --

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 112 AM EDT MON APR 22 2024

VFR conditions prevail under clear to mostly clear skies outside
of some early morning fog in the deepest sheltered valleys. Winds
will also be light, but peak in the afternoon generally out of the
west-northwest in the afternoon at around 5 kts or less.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
Frost Advisory until 9 AM EDT Tuesday for KYZ044-050>052-058>060-
068-069-079-080-083>088-104-106>120.
-- End Changed Discussion --

&&

$$

UPDATE...JP
SHORT TERM...HAL
LONG TERM...VORST
AVIATION...CMC