527
FXUS63 KJKL 292006
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
406 PM EDT Sun Jun 29 2025

.KEY MESSAGES...

- Hot and humid conditions will continue through Monday. Heat
  indices will peak in the 90s to around 100 degrees through
  Monday.

- Diurnal shower and thunderstorm chances continue through
  Tuesday.

- A cold front passage on Tuesday will bring temporary relief
  from the sustained heat and humidity.

- Daily high temperatures are favored return to the 90s from next
  Saturday onward.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 406 PM EDT SUN JUN 29 2025

The last Sunday of June is going out on a seasonably hot and humid
note with widespread temperatures between 85 and 90F this
afternoon while dew points range in the upper 60s to lower 70s in
most locales. Convection so far has been minimal, confined to
some spotty activity over the Bluegrass and perhaps a few
sprinkles in the vicinity of Big Black Mountain. The surface
analysis shows little in the way of a defined pressure regime over
eastern Kentucky -- diurnal and topographic effects predominate.
Aloft, a shortwave trough extends from Minneapolis, MN southward
to the Mid-Mississippi Valley and appears to be supporting at
least scattered convection over central and western Kentucky.
Further upstream, a more substantial 500H trough extends southwest
from Lake Winnipeg to near Yellowstone National Park. A cold
front extends southward from this system`s surface reflection over
northwest Ontario across Iowa and then southwestward into
Colorado.

For the remainder of the daylight hours, still expect at least
scattered shower and thunderstorms (30-50 PoP) to develop across the
area with the best chances generally southwest of KY-15 due to a
combination of better topographical forcing and some weak upper
level support from the approaching shortwave trough. With relatively
weak instability and minimal shear, anticipate mainly garden variety
storms. The strongest storms could produce some brief wind gusts and
perhaps a very isolated instance of excessive rainfall.

For tonight, much of the time will be dry. However, with the
shortwave trough passing aloft, a few showers or thunderstorms
cannot be ruled out with better chances generally toward
and north of I-64. It will still be warm and muggy with lows
generally ranging from 65-71F. Fog formation is a good bet in the
favored river valleys and where rainfall occurs toward or after
sunset. On Monday, heights aloft will begin to fall as the cold
front and its parent 500H trough approach the Lower Ohio Valley.
Another disturbance skirting around the base of the trough
is likely to help spark additional convection during the day on
Monday. The primary concern with those storms remains the
possibility of isolated excessive rainfall as the swampy, humid air
mass lingers overhead. It will again be hot with high temperatures
from 85 to 90F at most locales.

On Monday night, shear will become strong enough for semi-organized
convection ahead of the cold front; yet instability will wane after
sunset. The NAMNEST hints at a possible QLCS diving southeast
ahead of the front and then eventually decaying as it nears the
I-64 corridor. This is a distinct possibility and could portend a
blustery but weakening squall line impacting portions of the
forecast area late Monday evening, especially toward the
Bluegrass; but, forecaster confidence in anything approaching
severe limits is very low at this time. Otherwise, Monday night
should be warm and a bit breezy with lows in the upper 60s to
lower 70s. Some temporary relief from the muggy weather is on the
way though -- the well-advertised cold front is expected to be on
our northwestern doorstep by sunrise Tuesday morning.

.LONG TERM...(Monday through Saturday)
Issued at 424 PM EDT SAT JUN 28 2025

The 28/12z model suite analysis beginning Monday morning shows a
digging trough, extending from Northern Ontario to the Central
Plains, diving southeastward toward the Lower Ohio Valley. A
surface cold front initially trails from an ~1003 mb low over
James Bay southwestward across Lower Michigan and well beyond
into the eastern Kansas Plains.

This system is slated to bring temporary relief from the
heat/humidity mid-week before upper level ridging tries to re-
establish its grip on the Coalfields next weekend. The parent
trough drops into the Commonwealth by Monday and early Tuesday,
along with an associated surface cold front, and finally sweeps
away the muggy, high PWAT air mass that is currently plaguing the
region. Some modest increase in shear is likely along/ahead of
the cold front, but the overnight/morning frontal passage will
occur when instability is minimized. Similar to recent days,
disturbances aloft/ahead of the cold front are likely to bring
another round of scattered showers and thunderstorms on Monday
prior to boundary`s arrival. Rain chances are favored to linger on
Tuesday as the front makes a slow departure. As the 500H trough
slowly shifts eastward on Wednesday and Thursday, incoming
large-scale ridging will support high pressure building in at the
surface. However, a few weak disturbances riding down the eastern
side of the ridge might be able to spark a very isolated shower
or thunderstorm. A gradual warming trend is also likely as 500 mb
heights rise back to around 592 dam.

Sensibly speaking, expect more of the typical summertime showers and
thunderstorms, most numerous during the afternoon and evening, on
Monday before a period of more widespread showers and
thunderstorms move through Monday Night into Tuesday. Mostly sunny
days and mostly clear nights with just an isolated (~20% or
lower) shower or thunderstorm threat follow from Wednesday onward.
Fog can be expected in the valleys on most nights, least
extensive Monday night. Temperature-wise, daily maximum
temperatures in the 85 to 90F range on Monday cool to the 81 to
86F range on Tuesday. Nighttime lows dip solidly into the lower
and mid 60s for most as well. From then onward, look for
temperatures to gradually warm back to between 90 and 95F on
Saturday. The Independence Day holiday is shaping to be mostly
sunny and seasonably hot with just the small chance of an isolated
shower or thunderstorm.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 146 PM EDT SUN JUN 29 2025

The cumulus field over eastern Kentucky at TAF issuance is likely
to blossom into scattered showers and thunderstorms this
afternoon and evening. While VFR conditions should generally
prevail through sunset, briefly reduced flight categories are
likely under any passing shower or storm. Once deep convection
diminishes, fog formation is favored again tonight in the typical
valleys. However, any fog impacts at the TAF sites is uncertain,
likely dependent upon where/when rainfall occurs. Fog clears after
sunrise on Monday with renewed chances for storms by the end of
the period. Winds will be variable, generally under 5 kts, through
tonight, except potentially gusty and erratic near thunderstorms.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...GEERTSON
LONG TERM...GEERTSON
AVIATION...GEERTSON