227
FXUS63 KLMK 161030
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
630 AM EDT Mon Sep 16 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*  Dry and warm conditions expected across the region Monday.

*  Chances for rain (<30%) possible around midweek for areas along
   and east of I-75; otherwise, mostly dry and warm through next
   weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 346 AM EDT Mon Sep 16 2024

Early morning satellite imagery shows mostly clear skies across much
of southern Indiana and central Kentucky.  Lingering cloudiness was
noted across western Kentucky where the remnants of tropical
cyclone Francine continue to slowly spin down.  Temperatures across
the region were in the upper 50s and lower 60s.  The exception was
far western KY where cloud cover was keeping temperatures in the
lower 70s.  For the remainder of the overnight hours, no significant
weather is expected.  Overnight lows will cool several more degrees
with most locations seeing upper 50s and lower 60s for lows.

For today, surface high pressure will continue to be centered over
the northeastern US.  A surface area of low pressure off the
Carolina coast will attempt to attain tropical characteristics as it
moves inland across the Carolinas.  Some high clouds from that
system may spill over into far eastern KY, perhaps as far west as
the I-75 corridor.  A dry day is expected across the region with
afternoon highs in the mid-upper 80s west of the I-65 corridor.
Lower 80s will be found east of I-65.  Depending on how much cloud
cover advects westward, highs out east of I-75 may only reach the
upper 70s to around 80.  Winds are expected to become somewhat gusty
this afternoon as good mixing in the PBL takes place.  The extent of
mixing may be offset with mid-high level clouds streaming into our
eastern areas.  Overall wind gusts of 18-24 mph will be possible
east of I-65.

For tonight, skies will start off clear to partly cloudy across the
region.  Mid-high level clouds from the Carolina tropical system
will expand westward perhaps to the I-65 corridor or so.  Overnight
lows will be in the upper 50s to the very low 60s.  Tropical showers
associated with the Carolina system may work into portions of
eastern KY late tonight.  For now will introduce a slight chance PoP
in areas east of I-75 toward dawn Tuesday.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 346 AM EDT Mon Sep 16 2024

The focus for the start of the long term remains the
potential development of tropical cyclone eight off the coast of the
Carolinas. There remains plenty of discrepancies between the models
when it comes to the overall details but the trend remains that it
will impact our far eastern counties (location along and east of the
I-75 corridor) with much needed rainfall. Depending on the model, we
could see precipitation as early as Monday night/Tuesday per the
GFS/NAM or it could be late as Tues Night into Wed per the EURO. As
was mentioned in the previous discussion, The suite of NBM ensembles
show about a 30-50% chance of measurable precipitation (greater or
equal to 0.01") with those chances dropping off dramatically as you
work towards I-65 to around 10-20%. It will really come down to the
development of the system over the next 24 hours, and how it
interacts with the Appalachians as well as the upper ridge over New
England and associated sfc high pressure that is over the region.
All of these features could have some limiting impacts on how far
west this system gets through midweek. Current forecast is
advertising around 0.10" to 0.30" of rainfall with some models as
high as a half inch.

The upper low that has been impacting the region and creating the
Rex Blocking pattern over the weekend will meander across the Ohio
Valley and the Mid-Atlantic through about Thursday before it shifts
eastward over New England by the end of the week. Ridging over Texas
will build northeast towards the Great Lakes for the end of the week
into the weekend. This will develop another Rex Block as the
aforementioned upper-low retrogrades westward for the weekend.
Outside of the potential rain chance Tues and Wed the rest of the
forecast is pretty stagnant and unchanged. Highs Tues and Wed have a
large spread over the CWA due to cloud cover to the east and
sunshine to the west. Where there is more cloud cover highs will
range from the mid 70s to the east with upper 70s to near 80 close
to I-65. As you go west of I-65, highs will be in the low/mid 80s
due to more sunshine.

Thursday to the weekend will see a return to dry and sunshine. Highs
will be warmer than normal compared to mid Sept normals with daily
highs in the mid/upper 80s to near 90 towards the weekend with lows
generally near 60 each morning.

&&

.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/...
Issued at 629 AM EDT Mon Sep 16 2024

Thanks to the influence of high pressure just to our north, flight
categories will remain VFR through the forecast period. The main
impact to look for will be for some sites like SDF/LEX/RGA to see an
increase in winds with gusts approaching 15-20kts for a period in
the afternoon. By evening, winds will decrease but locations like
LEX could see increasing high clouds tonight from an approaching
system coming in off the Atlantic later today.

&&

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

&&

$$

SHORT TERM...MJ
LONG TERM...BTN
AVIATION...BTN