Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 201753
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
153 PM EDT Thu Aug 20 2026

.KEY MESSAGES...

* There is a low (10-20%) chance for a pop up storm this afternoon,
  lingering through tomorrow across far southern Kentucky. The risk
  of severe weather is low.

* Another low (20%) chance will exist for storms on Saturday. It is
  unclear whether a severe weather risk can materialize.

* Milder conditions are forecast Sunday into Monday. There is a 40-
  70% chance (highest north) that temperatures fall into the 50s
  Sunday night.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 153 PM EDT Thu Aug 20 2026

***** LOW CHANCE OF STRAY SHOWER/STORM THROUGH FRIDAY *****

At 145pm Thursday afternoon, a cold front, recognizable via a wind
shift and gradually decreasing dewpoints, was located near the I-64
corridor. RAP mesoanalysis suggests 1000-2000 J/kg MLCAPE and 20-
25kt effective bulk shear ahead of this front, which could
certainly support a couple thunderstorms, however forcing along
this front may prove too weak to spark much, if anything, in the way
of convection. HREF 40km neighborhood probabilities for more than
40dBZ reflectivity, like NBM precipitation chances, generally peak
around 10-20% across the area through this evening, lingering where
the front stalls across extreme southern Kentucky overnight.
Elsewhere, patchy fog may develop as temperatures drop into the mid
to upper 60s - a few degrees below current dewpoints. HREF/NBM
probabilities for visibilities less than 1 mile generally run 20-30%
overnight into Friday morning - highest during the 4-8am EDT
timeframe.

Tomorrow, a weak disturbance riding northeastward along the
Appalachians could trigger a storm or two along the far southeastern
border of our county warning area (CWA), but most activity should be
confined to the Cumberland Plateau. Any early morning fog should
lift into low stratus by mid morning, and then gradually break up
through mid afternoon when breaks of sunshine should warm the area
once again into the low-mid 80s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 153 PM EDT Thu Aug 20 2026

***** LOW SEVERE STORM RISK SATURDAY, COOLER SUNDAY-MONDAY *****

A stronger trough is forecast to dive south out of Manitoba Friday
night, reaching the Lower Great Lakes by Saturday evening and
bringing a cold front through the local area by Sunday morning. It`s
unclear whether we will see sufficient moisture return ahead of this
front to have a severe thunderstorm risk, particularly with the
minimum in shear along the trough axis during the afternoon.
However, some machine learning guidance is advertising 15+% severe
probabilities over portions of the local area. At this time, SPC`s
day 3 outlook clips areas east of I-75 in northeast Kentucky with a
level 1 of 5 (marginal) risk, which is also the area ML guidance is
hitting the hardest. Still, a couple RRFS iterations have hit areas
west of I-65 (where shear is slightly higher under northwest flow)
with a separate area of thunderstorms; we`ll keep an eye on this
signal in the other CAMs once they begin to capture the event.

Behind the front, conditions should turn seasonably dry and slightly
cooler with afternoon highs in the low 80s both Sunday and Monday,
and overnight lows possibly (40-70% chance, according to NBM)
dipping into the 50s in spots both Sunday and Monday nights.
Eventually, however, ridging should expand back into the region from
the west, bringing an attendant increase in warmth/humidity and
storm chances (20-40%) along its periphery by midweek.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 153 PM EDT Thu Aug 20 2026

An area of MVFR ceilings lingers across northern Kentucky early
Thursday afternoon, though cloud bases have been gradually rising
and should be mostly/entirely in the low VFR category in the next
couple of hours. A cold front dropping south across the area will
bring a wind shift to a north-northeasterly direction as it
progresses from north to south this afternoon, then winds should
drop off overnight as high pressure builds over the area. Patchy fog
is forecast to develop overnight and will pose the highest risk for
substantial visibility reductions at BWG and RGA during the 08-12z
timeframe, then this should lift into MVFR stratus and later (15-
18z) break up. There is a small (10-15%) chance for a stray shower
or storm this afternoon, mainly at BWG, RGA, and LEX, but confidence
was too low to add this to the TAFs at this time.

&&

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

&&

$$

SHORT TERM...JRB
LONG TERM...JRB
AVIATION...JRB