538
FXUS63 KLMK 171040
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
640 AM EDT Tue Sep 17 2024

.KEY MESSAGES...

*  Chances for rain Tuesday and Wednesday for areas along and east
   of I-75.

*  Summer warmth returns by Friday and Saturday with highs nearly 10
   degrees above seasonal normals with temperatures near or even
   into the low 90s.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 334 AM EDT Tue Sep 17 2024

Upper low associated with the former Potential Tropical Cyclone
Eight is parked over the western Carolinas and won`t go anywhere
fast. However, it`s still trying to sling moisture westward across
the Appalachians, and that will be the main weather feature of
interest in the Ohio Valley today and tonight.

Confidence in the forecast is medium at best, with the most likely
impact being an increase in cloud cover, mainly as a mid-level
ceiling. How far west any precip bands can advance is less certain,
especially with dewpoints still in the lower 50s in the Bluegrass
region. By late in the day, we should be able to squeeze out a few
showers along the I-75 corridor, but anything attempting to advance
much farther west than the Kentucky River should weaken quickly.
Have included a 20-30% chance for showers for the afternoon and
evening, roughly along and east of Highway 127.

Temps will be heavily impacted by the cloud cover, with highs
limited to the mid/upper 70s in the Bluegrass region, but
potentially getting well into the 80s west of I-65. Expect a similar
but opposite spread in overnight lows, with the cooler temps west
and warmer east.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 334 AM EDT Tue Sep 17 2024

We will remain under the influence of the meandering stacked sfc and
upper low that will briefly stall out over the eastern TN River
Valley for the middle of the week. This will keep some linger rain
chances across our far eastern CWA, in generally the same place as
Wednesday, along and east of the I-75 corridor. Cyclonic flow around
the system will keep us under more north to northwesterly flow. This
will give us gradient of highs across the CWA with temperatures
ranging from near to low 80s east of I-65 with low/mid 80s to the
west.

Thursday and into the weekend, the upper low will start to work off
to the northeast as strong ridging builds into the Ohio Valley and
Great Lakes from Texas. As heights increase aloft and sfc high
pressure builds in over the region, the rest of week and into the
weekend will be dry and unseasonably warm. Highs will build back
into the mid to upper 80s by Thursday. We will still see that east
to west temperature gradient with the lingering cyclonic flow from
the departing system. By Friday and Saturday it will be much warmer
and very summer-like with highs in the upper 80s to even low 90s
across central KY and southern IN.

An approaching system and upper trough across the Dakotas and Canada
will work eastward towards the Upper Great Lakes by Sunday. Models
differ some on this system but with increased moisture flow from the
south and a slight inverted sfc trough, we could see a slight
increase in isolated to maybe scattered showers and storms. Still to
early to make a call given the discrepancies in the models.
Temperatures will remain warm but a bit cooler than the end of the
week with highs in the mid 80s.

&&

.AVIATION /12Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 638 AM EDT Tue Sep 17 2024

VFR ceilings and vis to initialize this TAF set, even with a few
showers around RGA. Upper low over the western Carolinas won`t go
anywhere fast today, so we could continue to see light rain showers
intermittently around LEX and RGA throughout the day.  Still quite a
bit of dry air to the west, so these showers will mostly dissipate
as they try to push westward. Will handle RGA with a TEMPO, but
carry a PROB30 late in the afternoon for LEX and keep SDF and BWG
dry. E-NE winds will persist with speeds generally AOB 10 kt.

&&

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

&&

$$

SHORT TERM...RAS
LONG TERM...BTN
AVIATION...RAS