662
FXUS63 KLMK 100840
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
440 AM EDT Mon Jun 10 2024

.KEY MESSAGES...

* Below normal temperatures and humidity Monday and Tuesday.

* A warming trend with hot and dry conditions likely for late
  this week into next weekend.

&&

.UPDATE...
Issued at 439 AM EDT Mon Jun 10 2024

Dense fog has developed in south central Kentucky as clear skies
has allowed for good radiational cooling where rainfall occurred
Sunday. A Dense Fog advisory has been issued for areas along and
south of the Cumberland Parkway until mid morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 258 AM EDT Mon Jun 10 2024

Latest fog product view on satellite is showing an area along and
south of the KY Parkway system with some fog development where
recent rainfall occurred Sunday.  A special weather statement has
been issued for locally dense fog and rapidly changing visibilities
this morning for travelers.

Dry frontal passage today and associated upper level trough of low
pressure will keep conditions on the cool side of normal with highs
in the mid to upper 70s, which is between 5 and 10 degrees below
normal for mid June.  Some afternoon clouds may pop up in the
afternoon, but mainly sunny skies will prevail with lots of dry air
in place (PWs based on sounding climo between 10th and 25th
percentile today and tonight).  Outside of a few clouds, the only
other sensible weather will be an occasional NNW wind gust up to 15
mph.  Some patchy valley fog is possible overnight into the early
morning hours Tuesday, but any impact will be minor and limited to
low lying areas.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 258 AM EDT Mon Jun 10 2024

The extended forecast period from Tuesday through next weekend is
expected to feature a lot of dry weather and a big increase in
temperatures as a dome of hot temperatures gradually builds across
the central and eastern portions of the CONUS. At the beginning of
the period on Tuesday, mid and upper-level troughing will still be
located over the east coast while broad ridging will abound along
and west of the Rockies. At the surface, high pressure is expected
to be located near the confluence of the MS/OH River, with the air
mass overhead being somewhat cooler and considerably drier than
normals for mid June. Both the NAEFS and EPS Ensemble Mean PW
values, ranging from 0.4" to 0.6" across the area, are below their
respective model climatology`s 5th percentile. For reference, the
10th percentile PW value in observed soundings on June 11th is 0.57"
at ILN and 0.76" at BNA. This dry air mass will stick around into
the middle and latter portions of the week with modest moisture
return expected, allowing for large diurnal temperatures ranges even
with an overall warming trend.

Wednesday into Thursday, the synoptic pattern will transition to
flat, broad ridging with the primary baroclinic zone being shoved
into the northern U.S. and southern Canada as the heat dome spreads
eastward. Low-amplitude troughs will ride along the top of the
building ridge, with associated moisture and precipitation chances
remaining well north of the Ohio Valley. Increases in 850 mb
temperatures from Tuesday (9-10 deg C) to Thursday (16-18 deg C)
will be a good proxy for rises in daytime highs given continued dry
air through the column. This would translate to a roughly 15 deg F
increase in expected temperatures, which would take us from readings
in the mid-upper 70s on Tuesday to a few degrees either side of 90
by Thursday. Fortunately, dew points should remain low enough to
keep heat indices in check.

By Friday, a more substantial shortwave will try to cut into the
northeastern flank of the upper ridge, bringing a cold front with it
as it moves across the Great Lakes and into the northeastern U.S. By
the time the front reaches our vicinity, it will have lost much of
its upper level support as the aforementioned trough progresses
quickly eastward. While there will be an area of increasing moisture
ahead of the front and some lift associated with FROPA, the
dilapidated state of the boundary should limit shower/storm chances.
For what it`s worth, the GEFS does depict a more robust
trough/front, which would favor more widespread precipitation
chances, while the EPS and GEPS families have a weaker front and
less in the way of precipitation. At this time, think most areas
will experience little more than a few extra clouds and a wind shift
Friday into Friday night.

If the front makes it through the region Friday night, slightly
cooler temperatures would be expected within a low-level NE flow
regime on Saturday. However, this should be short-lived as the upper
ridge builds quickly back to the east Saturday night into Sunday. At
this time, Sunday into early next week has the potential to be
rather hot, although increasing moisture from the Gulf of Mexico
early next week may limit diurnal temperature ranges and increase
cloud cover/precipitation chances.

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1238 AM EDT Mon Jun 10 2024

VFR conditions are expected for the next 24 to 30 hours. Mostly
clear skies tonight will be replaced with cumulus during the day
tomorrow. Winds will ease tonight before increasing out of the north-
northwest tomorrow.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Dense Fog Advisory until 8 AM CDT this morning for KYZ070>078-
     081-082.
IN...None.

&&

$$

UPDATE...MCK
SHORT TERM...MCK
LONG TERM...CSG
AVIATION...MCK