342
FXUS63 KLMK 061407
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1007 AM EDT Sat Jul 6 2024

.KEY MESSAGES...

*   Mostly sunny skies, seasonably warm temperatures, and lower
    humidity expected this weekend

*   Remnants of tropical cyclone Beryl may affect the Ohio Valley by
    late week

&&

.UPDATE...
Issued at 1006 AM EDT Sat Jul 6 2024

Slightly drier and cooler conditions prevail today in the wake of a
weak `cold` front. Satellite shows some high level clouds with 15kft
bases streaming in from western Tennessee this morning, but drier
air in the low to mid levels will keep us dry today. Forecast
remains on track.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 322 AM EDT Sat Jul 6 2024

This morning, quiet and dry conditions are present across central
Kentucky and southern Indiana with scattered high clouds observed
over the region on latest nighttime microphysics satellite imagery.
Drier air is continuing to work its way from west to east across the
Ohio and Tennessee valleys behind a low pressure system that is now
east of the Appalachians. In the middle and upper levels, upper air
analysis reveals broad troughing in between the Rockies and the
Appalachians, with this trough helping to push the humid, unstable
air mass which has been present over our region for the past few
days off to the south and east. Temperatures at this hour range from
the mid 60s to the mid 70s, with most locations expected to drop
into the 60s before dawn this morning. While some patchy river
valley fog will be possible over the next few hours, persistent
light westerly winds should keep any fog confined to the deepest
valleys.

All in all, today looks to be quite nice for early July, with mostly
sunny skies and highs in the mid-to-upper 80s expected. As surface
high pressure moves from the central Plains toward the mid-
Mississippi Valley later today, the pressure gradient will weaken,
with westerly winds expected to remain between 5 and 10 mph later
today. This low-level westerly flow will help to reinforce the drier
air mass overhead, with PW values expected to range from 1-1.25" and
dewpoints residing in a more comfortable range in the low-to-mid 60s.

Tonight, high pressure will be over the area, allowing for mostly
clear skies and light and variable winds. The lower dewpoints will
allow temperatures to cool more efficiently, and another morning of
lows in the 60s is expected for most on Sunday morning. A few upper
50s will be possible in rural areas and sheltered valleys. Speaking
of the valleys, depending on how much mixing of low-level moisture
takes place this afternoon, conditions are otherwise favorable for
areas of fog Sunday morning. For now, will carry a patchy fog
mention in all of the river valleys, though this may need to be
augmented depending on low-level moisture trends later today.
Otherwise, quiet weather should continue into the day on Sunday.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 322 AM EDT Sat Jul 6 2024

Sunday through Tuesday Night...

Dry weather conditions are expected at the beginning of the period
as high pressure and a southwest flow aloft persist.  Highs on
Sunday will average in the upper 80s to around 90 with lows in the
upper 60s to the lower 70s.  Moving into Monday, the day will start
off dry, but moisture coming off the Gulf will push into the region
from the south.  Some isolated convection may fire mainly across
southern KY Monday afternoon/evening.  Still seeing an inversion in
the 850-700 mb layer in soundings on Monday which may end up holding
and keeping things a bit drier than what guidance currently
suggests.  Highs on Monday look to average in the upper 80s to the
lower 90s with overnight lows in the upper 60s to the lower 70s.

By Tuesday, an upper level trough axis will push into the region
from the north/west.  In addition, a deep moisture plume will lift
northward into the region associated with the remnants of tropical
cyclone Beryl.  PoPs look to be rather scattered in the afternoon
but look to become more widespread Tuesday night.  Highs Tuesday
should be a bit cooler with anticipated clouds and precipitation
coming into the region late.  Will go with highs in the mid-upper
80s and lows Tuesday night will be in the upper 60s to the lower 70s.

Wednesday through Friday...

Pattern looks to become a bit more active for Wednesday/Thursday as
we remain in the deep moisture plume associated with the remnants of
tropical cyclone Beryl.  Large majority of the ensemble guidance
shows the remnants passing through the Ohio Valley in the Wed/Thu
time frame.  Where exactly the heaviest QPF will fall remains to be
seen.  Not surprisingly, we`re still seeing a bit of spread in the
guidance here.  The Euro remains on the western side of the guidance
envelope with a swath of QPF from NE TX through AR and into W KY and
southern IN.  The GEM is a bit more east with the axis centered
through the LMK CWA.  The GFS remains a bit more diffuse and more to
the east/southeast.  While these differences remain large, we expect
a convergence of forecasts over the next several days.  Will
continue to watch to see if the remnants track right thorugh the
region as this could bring excessive rainfall and the threat of some
strong/severe storms. For now, will keep highest PoP chances in the
Wed/Wed night period with more of climatological PoPs in the Thu/Fri
period.

Highs on Wednesday look to be in the upper 70s/lower 80s given
anticipated clouds/precip.  Lows should be in the upper 60s to
around 70.  Temps look to rebound a bit on Thursday/Friday with
highs in the mid-upper 80s.  Overnight lows will remain in the upper
60s/lower 70s.

&&

.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 652 AM EDT Sat Jul 6 2024

VFR conditions are expected today as high pressure moves into the
region from the west. Cirrus clouds will continue to stream across
from SW to NE, with a few 4-6 kft diurnal cu expected to develop for
the late morning and afternoon hours. Winds will be W/NW at around 6-
10 kt for the afternoon and evening hours before calming after
sunset this evening.

At this time, there is a low confidence potential for reduced
visibilities from fog Sunday morning at all sites except for SDF.
The extent to which fog forms tonight will be dependent on how well
the boundary layer moisture mixes out this afternoon, although light
winds and clear skies with high pressure overhead would suggest
otherwise favorable conditions for fog development. For now, will
mention fog potential at HNB and RGA where there is the highest (but
still low) confidence in development.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE...DM
SHORT TERM...CSG
LONG TERM...MJ
AVIATION...CSG