271
FXUS63 KJKL 062314
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
714 PM EDT Sat Jul 6 2024

.KEY MESSAGES...

- Seasonably hot and rain-free weather follows for tomorrow before
  a humid and unsettled weather pattern develops for the new work
  week.

- Forecasters will continue to monitor Beryl`s remnants for possible
  impacts here in eastern Kentucky.

&&

.UPDATE...
Issued at 713 PM EDT SAT JUL 6 2024

Increased cloud cover is streaming into eastern Kentucky from
central and eastern Tennessee from an area of slightly increased
instability and moisture. This may have an impact on the extent
and severity of fog coverage overnight if the cloud cover remains
persistent enough. Otherwise, changes were minimal with the
forecast initialized using the latest hourly observations.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 420 PM EDT SAT JUL 6 2024

Aloft seeing minor height rises across the eastern CONUS through
the short term while a broad trough over the Great Plains begins
to fill and lift north-northeastward towards the Upper Midwest. At
the surface high pressure shifts slowly from the Midwest into New
England by the of the period. That makes temperatures and the
potential of fog the main forecast challenges for the short term.

Sensible weather features a moderation or warming in temperatures
through the period. The seasonably pleasant (mid 80s) and
relatively comfortable weather experienced today will feel a bit
warmer tomorrow as temperatures climb to near 90. However, winds
remain out of the north-northeast through the period. Consequently
do not expect a surge in moisture across the area and a return to
super muggy conditions, though surface dew points will tend to
creep up as the high passes to our east and return flow begins to
kick in by the end of the short term. Overnight lows will be
pleasantly cool through the period, with our cooler valleys
dropping to around 60 tonight and lower 60s tomorrow night. Cross
over temps are generally in the low to mid 60s. Thus we can expect
the formation of some valley fog through the overnight, possibly
not quite as dense and widespread as this morning as a result of
some of our boundary layer moisture being mixed out during the day
today.

.LONG TERM...(Monday through Saturday)
Issued at 505 PM EDT SAT JUL 6 2024

The 06/12z model suite upper level analysis beginning Monday morning
shows mean ridging extending the Western Atlantic into the Southeast
US and Greater Antilles. To the northwest, a positively-tilted
trough extends from a parent low over the Hudson Bay to the
Southern High Plains. Hurricane Beryl should be nearing or making
landfall around this timeframe as well, likely over southeast
Texas. At the surface, a wavering frontal boundary extends from
the New England Coast, southward along the eastern slopes of the
Appalachians, and then more westward along the Gulf Coast to the
vicinity of Beryl. A cold front extends northward from Central
Texas to a weak surface low over Lake Superior. Weak surface
ridging, wedged between these frontal boundaries, extends from
the Mid-Mississippi Valley up into the Mid-Atlantic/Lower Great
Lakes.

The surface high over the Ohio Valley will become increasingly
squished between the upper level trough/cold front advancing from
the west on Monday and Tuesday. Convection is expected to develop
over the Central and Southern Appalachians on Monday afternoon
and again on Tuesday as moisture tries to seep northwestward
into the Ohio Valley. While a majority of this activity should
remain south and east of the JKL CWA on Monday, some spotty
convection cannot be ruled out closer to the Virginia and
Tennessee borders. With the continued rise in moisture, deep
convection on Tuesday is expected to be more scattered to numerous.
Forecaster confidence is increasing that deeper tropical moisture
with Beryl`s remnants will arrive late Tuesday evening or night
as the aforementioned cold front half-heartedly pushes into the
Lower Ohio Valley. Return flow ahead of the boundary will pull
anomalously high 2.0-2.2+ inch PWATs into the Ohio Valley. The
strength and track of Beryl`s post-tropical wind field and surface
low (still a point of uncertainty in the guidance) will determine
the location of any notable axis of heavy rainfall as well as the
degree of downslope rain shadowing over the southeastern 2-3
tiers of counties. Modeled instability is very meager with the
tropical remnants, limiting the severe weather threat. However, a
very moist sounding to near the tropopause including a deep
saturated warm layer will be supportive of efficient rainfall
processes and torrential rainfall rates. The big question remain
how much rain shadowing occurs. As Beryl`s remnant low departs to
the northeast, anticipate that its cyclonic circulation will aid
the cold front in pressing the remainder of the way through
eastern Kentucky by Friday or Saturday. However, lingering
cyclonic flow with the trough passing aloft will likely remain
supportive of at least some spotty diurnally driven convection
heading into next weekend.

In sensible terms, mostly sunny skies should generally be the rule
on Monday with just a small shower or thunderstorm chance (10-30%)
south of the Mountain Parkway, highest near the Virginia and
Tennessee border. It will be hot and more humid with highs in the
upper 80s to the lower 90s but the increasing humidity values will
buoy heat indices close to 100 in the warm spots. A similar story
is expected to unfold on Tuesday, except rain chances (40 to 60%)
are better by the afternoon. The best rain chances of the period
(60-70%) come late Tuesday night through early Thursday morning
with the passage of Beryl`s remnants. Rainfall during this time
period could be torrential at times, leading to instances of high
water. Temperatures will trend cooler, generally lower to middle
80s for highs on Wednesday and Thursday, with all of the clouds
and precipitation. Warmer temperatures (middle to upper 80s) and
more dry time can be expected for Saturday and Sunday, though a
shower or thunderstorms cannot be ruled out on either day,
especially during the afternoon and early evening. Nighttime lows
in the mid 60s to mid 70s are forecast through the period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 135 PM EDT SAT JUL 6 2024

VFR flight conditions are being forecast through the period.
Overnight valley fog development is not expected to impact any
terminals overnight. Otherwise, regional satellite loops is
showing some considerable mid and high clouds upstream. These
cloud will pass across the area between now and this evening.
Winds will average around 5 kts or less through the period,
generally from the west. KSYM may tend to flow out of the west-
southwest due to local terrain effects.

&&

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

$$

UPDATE...CMC
SHORT TERM...RAY
LONG TERM...GEERTSON
AVIATION...RAY