325
FXUS63 KLMK 171703
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
103 PM 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.

&&

.UPDATE...
Issued at 907 AM EDT Tue Sep 17 2024

Light spotty rain showers have pushed into the region this morning
but are encountering a layer of dry air (surface up to ~700mb) that
is limiting accumulations. Most KY Mesonet and ASOS/AWOS readings
across the Kentucky Bluegrass region where the showers are most
prevalent on radar have not picked up any measurable rain at this
point. Expect much of the same for the remainder of the day, with
only very light amounts anticipated across our eastern zones. Did
adjust temps down slightly across the east where the cloud cover and
spotty showers should keep temperatures in the low/mid 70s for much
of the day. Otherwise, forecast is on track.

&&

.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 /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 102 PM EDT Tue Sep 17 2024

Scattered showers continue to push into eastern regions of the CWA
but are dissipating with westward extent as they encounter drier
air. This activity will likely continue through the remaining
daylight hours but begin to taper down overnight. Cigs/Vis should
stay in the VFR range through most of the forecast period, but could
flirt with MVFR conditions toward dawn tomorrow as low level
moisture works in from the east. Best chances for any sort of flight
impacts would be along and/or east of I-65.

&&

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

&&

$$

UPDATE...DM
SHORT TERM...RAS
LONG TERM...BTN
AVIATION...DM