000
FXUS63 KJKL 231326
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
926 AM EDT Tue Apr 23 2024

.KEY MESSAGES...

- Dry and breezy conditions today will approach critical fire
  weather thresholds.

- A weak passing cold front will bring light showers to most
  locations Tuesday night into early Wednesday morning.

- Below normal temperatures return by Thursday morning, bringing
  the risk for patchy frost in valleys.

- Temperatures then trend well above normal for the weekend.

&&

.UPDATE...
Issued at 926 AM EDT TUE APR 23 2024

High pressure has settled to our southeast into the Heart of
Georgia and Lowcountry region. The weather will be dry and warm
with highs closer to normal right around 70 degrees this afternoon.
We expired the Frost Advisory this morning and updated subsequent
products to take that wording out. Outside of this only minor
changes to blend in the latest obs and trends.

UPDATE Issued at 711 AM EDT TUE APR 23 2024

The forecast remains on track. Mainly freshened up the hourly
temperatures and dew points through this morning, incorporating
the latest trends in the observations.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 334 AM EDT TUE APR 23 2024

The latest upper level map features seasonably deep lows churning
over southeastern Canada, with a positively tilted trough aligned
southwest through the northern Plains, and then more west through
the northern Rockies. A notable vorticity maximum is moving over
the Upper Midwest within this long wave trough. Meanwhile, a short
wave ridge is retreating east near and along the Appalachians. At
the surface, high pressure is positioned from New England through
the lower Mississippi Valley. Elongated low pressure is seen
across southern Ontario, with a cold front arced south through
the Midwest, and then southwest through the central Plains.
Besides some passing high clouds, skies have been mostly clear
over eastern Kentucky, with temperatures currently ranging from
the mid 30s at the colder valley sites, to the upper 40s atop the
ridges.

The models are in good agreement through the short term period.
The Upper Midwest vorticity maxima will open up and cruise
southeast, reaching the Great Lakes and portions of the Ohio
Valley by this evening. This wave will continue more eastward
Tuesday night, before eventually meeting up with more amplified
short wave energy rotating in from southern Hudson Bay on
Wednesday over New England. At the surface, a cold front will
progress through the Ohio and Tennessee valleys tonight into
early Wednesday, bringing a round of light rain showers to our
area.

For today, deeper mixing will allow for drier air to mix down from
late this morning through this afternoon, as the pressure gradient
increases between the approaching cold front from the northwest,
while high pressure retreats further away to our southeast.
Consequently, used more 10th percentile of the blended guidance
for the dew points, while allowing for highs in between the 50th
and 75th percentile, with most locations seeing lower 70s, with
some spots achieving mid 70s. Southwest winds will increase to 10
to 15 mph, with gusts of 20 to 25 mph. Given the combination of
the lower relative humidity and the gustier southwest winds, will
hoist a Special Weather Statement highlighting the fire weather
concerns. PoP chances will increase to likely to categorical
(60-80%) tonight associated with the passing cold front. QPF
continues to come in lean for this system, averaging less than a
tenth of an inch for most locations. Lows will average in the low
50s. A few showers will hang on across far southeastern Kentucky
early Wednesday morning, before high pressure builds in from the
northwest, with clouds breaking up in the afternoon. Highs will
retreat a few degrees compared to today, with upper 60s to lower
70s expected.

.LONG TERM...(Wednesday night through Monday)
Issued at 327 AM EDT TUE APR 23 2024

Models are in decent agreement in the evolution of the long term
period, yielding relatively higher confidence in the overall
forecast.

The period begins with northwest flow and cold advection underway
Wednesday night just upstream of the disturbance that crosses the
area Wednesday. A trailing wave within the northwest flow will bring
some clouds late Wednesday night into Thursday morning, but overall
this will have minimal impact on temperatures. Lows in the upper 30s
to lower 40s are expected on ridgetops and exposed areas, but
sheltered valleys will likely see another round of at least patchy
frost as temperatures fall close to freezing in the lower to mid
30s. Surface high pressure will result in light easterly surface
winds Thursday under sunny skies, with highs returning to near
normal in the mid to upper 60s north to mid 70s south.

Light easterly surface winds become more southeasterly with time
Thursday night as upper ridging moves overhead and warm advection
begins to increase. Lows Thursday night will trend about 5 degrees
warmer with 40s in most locations except for mid to upper 30s in the
more sheltered eastern valleys under gradually increasing cloudiness
from the southwest.

A warm frontal passage from south to north across the Ohio Valley
will bring increasing chances for showers and possibly a few
thunderstorms Friday into Friday night, though eastern Kentucky`s
proximity to the downstream upper ridging over the eastern slopes of
the southern Appalachians will likely keep much of the better
instability and moisture just to the west. With upper ridging
strengthening over the Mid-Atlantic through the weekend, the better
forcing for ascent in association with a low pressure system over
the Central US will remain over the Mississippi River Valley and
lower Ohio River Valley, which will result in only slight chance
PoPs at best for much of Saturday into Saturday night, with
increasing chances for showers and thunderstorms Sunday as the
weather system slowly starts to nudge the downstream ridge eastward.
High-end chance to likely (50 to 60) PoPs are expected Monday as the
cold front moves across the area, with surface high pressure nudging
into the area behind the front at the very end of the period Monday
night resulting in decreasing PoPs.

Temperatures will warm increasingly above normal from the 70s to mid
80s for highs through Sunday, then cool back into the 70s for most
areas Monday into Tuesday with the increased chance for showers and
storms. Lows will also be on the warm side in the upper 50s and 60s
this weekend into early next week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 711 AM EDT TUE APR 23 2024

VFR conditions will prevail through the vast majority of the
period. Some scattered high clouds will be seen at times through
this afternoon, before thicker mid-level clouds move in towards
dusk, as a cold front approaches from the northwest. Ceilings will
continue to lower through end of the period, and may flirt with
MVFR in places, especially as accompanying shower activity
gradually saturates the lower portion of the atmosphere overnight
into early Wednesday morning. Surface winds out of the south and
southwest at around 5 mph, will increase to 10 to 15 kts out of
the southwest, with gusts of 20 to 25 kts, from late this morning
through early evening. Winds will diminish somewhat after dark,
eventually shifting to the west behind the frontal passage.
Additionally, there will be a threat of LLWS for a time this
evening, as winds remain between 35 and 45 kts out of the
southwest at 2k feet agl through 06z, before diminishing.

&&

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

$$

UPDATE...DJ
SHORT TERM...GEOGERIAN
LONG TERM...CMC
AVIATION...GEOGERIAN