391
FXUS63 KJKL 150155 AAB
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
955 PM EDT Fri Jun 14 2024

.KEY MESSAGES...

- A weak cold front brings a low chance (10-40%) for a shower or
  thunderstorm through this evening, primarily north of the KY
  highway 80/Hal Rogers Pkwy/Cumberland Parkway corridor.

- Hot and somewhat humid weather arrives on Sunday and persists
  into the upcoming week. Afternoon heat indices may peak around
  100 at some locations Sunday through Wednesday.

- There is a slight chance of afternoon and evening thunderstorms
  on Monday, Thursday, and Friday.

&&

.UPDATE...
Issued at 955 PM EDT FRI JUN 14 2024

No significant changes to the forecast package at this time.
Tweaked temps to bring them in line with latest hourly surface
obs. Also made some minor adjustments to PoPs for ongoing activity
and trends. There is a definite trend downward in activity post
sunset. Convective outflow boundary continues to drop southward,
just about to reach the Ohio River proper. Can not rule out an
isolated shower or thunderstorm over the next 2-3 hours as it
continues to move southward. But expect coverage would be isolated
at best based on trends. Latest CAM solutions support this line
of thinking as well. Updated grids and zones have been issued.

UPDATE Issued at 610 PM EDT FRI JUN 14 2024

Convective initiation has been surprisingly robust along the I-64
corridor between Morehead and Louisville this evening ahead of
the cold front, in spite of little support from most of the CAMs.
Increased PoPs with thunder to slight chance/low chance over
southwestern portions of the forecast area down to the Hal Rogers
Parkway/Kentucky 80 corridor through 00z as this activity drops
southeast. Still anticipate that widely scattered convection will
impact locations northeast of KY-15 late this evening and early
overnight as the front passes. The latest SPC mesoanalysis
continues to show high DCAPE values of 1100 to 1400 J/kg,
indicative of abundant dry air in the mid-levels supportive of
damaging thunderstorm downburst winds if a particular storm
becomes strong.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 442 PM EDT FRI JUN 14 2024

Another seasonably warm afternoon has unfolded over eastern Kentucky
this afternoon with high temperatures as of 4 PM ranging from
from 85F in the northern foothills to 90F in the cities of
Monticello and Somerset. The heat was tempered at higher
elevations with the Pike County mesonet reporting a high
temperature of 81F atop Flatwoods and the Harlan County mesonet
measuring 74F atop Big Black Mountain. Very isolated
sprinkles/light showers have bubbled up today and impacted a few
locations. Regional satellite shows a band of towering cumulus
attending a cold front draped across southern Ohio, through
northern Kentucky and southwest through southern Indiana/Illinois.
Regional radar shows most of the shower and thunderstorm activity
with this front north and northeast of the JKL CWA at 4 PM. The
front is associated with a trough passing from the Great Lakes
toward the Mid-Atlantic/New England. Most of the system`s forcing
remains well to our north.

As that trough translates eastward, the associated cold front
will sag southward across eastern Kentucky this evening and
overnight. Sporadic convection is still expected to fire along the
cold front as it passes later this evening and early overnight,
especially over northeast Kentucky where low-level forcing may be
enhanced by weak outflow boundaries from other convection.
Otherwise, look for drier air to gradually work in overnight while
patchy fog tries to develop in some of the more sheltered river
valleys and in those areas affected by rainfall later this
evening. By Saturday morning, the front will be well to our south.
Strong upper level high pressure will then begin building over
the Southeast US and Ohio Valley for the remainder of the short-
term period. Cooler, drier, northerly low-level flow will knock
down temperatures a few degrees on Saturday before winds shift
back southerly late Saturday night and begin ushering in the
warmest air mass of the summer season thus far.

In sensible terms, look for spotty showers and thunderstorms this
evening and early overnight primarily northeast of KY-15, though
a stray shower cannot be ruled out further to the southwest.
Otherwise, partly cloudy skies and some patchy river valley fog
will be the theme. Overnight temperatures are forecast to be
seasonable with lows ranging from the mid 50s in northern valleys
where the cooler, drier air arrives first to the lower and middle
60s near the Tennessee border where the front arrives latest.
Saturday will be mostly sunny, less humid and slightly cooler with
highs ranging from the lower 80s in the northern foothills to the
upper 80s in the Middlesboro basin. With the drier air in place
and the commencement of low-level warm air advection, expect a
sharper ridge-valley temperature split to form on Saturday night
under mostly clear skies. Look for lows ranging from the lower 50s
in the coolest sheltered northeastern hollows to the mid 60s on
the mildest thermal belt ridgetops/slopes.

.LONG TERM...(Sunday through Friday)
Issued at 400 PM EDT FRI JUN 14 2024

Models are in general agreement for the overall pattern that will
affect our area during the long term period. Upper level high
pressure will start out centered in the vicinity of the southern
Appalachians on Sunday. It is expected to shift north to near NYC at
mid week, and then back south to the vicinity of VA on Friday.
The ridge is now expected to keep convection capped much of the
time for our area. However, one exception is Monday, when the GFS
and ECMWF both allow for a bit of mainly diurnal activity in the
afternoon and evening as an area of somewhat higher moisture
rotates around the western side of the high center. In terms of
model differences, the main issue is in the strength of the
high/ridge, with the ECMWF being stronger than the GFS, especially
later in the week. The weaker GFS allows for deep convection to
boil up on Thursday and Friday, whereas the ECMWF is dry. This
results in hotter temps in the ECMWF. Will allow for a model blend
to smooth out these differences for now, with only a slight
chance of precip to be mentioned.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 727 PM EDT FRI JUN 14 2024

VFR conditions will generally prevail through the TAF period. The
only exceptions will be at locations impacted by spotty shower and
thunderstorm activity this evening and valley fog later in the
night. A loose cluster of shower and storms is currently sinking
across central Kentucky toward LOZ at 2325z, but confidence is
low that this activity will actually reach the terminal before
dissipating. There is potential for a few showers and storms to
develop again later this evening, especially northeast of KY-15,
warranting VCSH mention at SJS and SYM between 01 and 04z.
Generally variable winds ~5 kts or less will persist through
tonight but gusty outflows could occur where thunderstorm activity
is present. MVFR or worse conditions are possible in valley fog
overnight, especially where rain occurs this evening.

&&

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

$$

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