511 
FXUS63 KLMK 060129
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
929 PM EDT Tue Oct 5 2021

.Forecast Update...
Issued at 929 PM EDT Tue Oct 5 2021

A solid batch of steady to briefly heavy showers are continuing to 
push northwestward along and north of the I-64 corridor at this 
hour. Have upped pops to categorical and some locations could pick 
up a quick 1"+ of rain. The highest MSD gage right now is .84" in 
less than an hour. Not too concerned about any minor flooding issues 
given how quick the showers are moving, however ponding of water on 
roadways is certainly possible. Updated products out shortly.

...A Few Rotating Storms Across Southern KY Wednesday?...

One other thing worth noting for tomorrow. A look at soundings and 
wind profiles for our SW CWA reveals favorable hodographs for some 
potential rotating and/or splitting updrafts. The ability to 
destabilize will be in question given heavy cloud cover, however 
some data does show at least some modest instability. Anything 
surface or near-surface based combined with low LCL's and notable 
effective SRH values in the 150-200 M2/S2 range could yield a 
marginal brief tornado threat. The main timeframe of concern would 
be later in the day/evening, but can't completely rule out any part 
of the day. Something to keep an eye on, and collaboration with SPC 
has agreed that a Marginal Risk may be needed tomorrow if data 
continues to support the threat.

Previous Update...
Issued at 757 PM EDT Tue Oct 5 2021

Numerous showers have developed just south of the I-64 corridor, and 
will push northwestward through our CWA over the next few hours. 
Upped coverage into the likely range for points along the I-64 
corridor to account for this. Some moderate rates are possible at 
times, and perhaps even briefly heavy. Also cannot completely rule 
out a few rumbles of thunder, although haven't seen any in a while. 
Otherwise, the forecast remains on track.

&&

.Short Term...(This evening through Wednesday)
Issued at 305 PM EDT Tue Oct 5 2021

Closed upper low over western Mississippi will retrograde NW into 
the Ozarks by Wed evening, with a sfc warm front pivoting N/NW into 
Kentucky tonight. ESE low-level jet will pull a decent moisture feed 
from east Tennessee into south-central Kentucky tonight, with a 
modest warm advection wing providing a short-lived opportunity for 
scattered showers farther north. Later in the night precip will be 
more focused to the south and west of Bowling Green, directed more 
in line with the low-level jet. 

Veering flow is expected on Wednesday, with a vort lobe swinging 
around the east side of the closed low late. This will bring another 
slug of moisture from the Tennessee Valley northward into central 
Kentucky toward sunset. Will carry likely/categorical POPs in the 
afternoon, but at this time it appears the QPF to support WPC's 
marginal risk for excessive rainfall will hold off until Wednesday 
night.

.Long Term...(Wednesday night through Tuesday)
Issued at 250 PM EDT Tue Oct 5 2021

Wednesday Night through Friday...By Wednesday night, the 576dm upper 
low is projected to be over the MO/AR border while deep southerly 
flow continues to advect warm, moist Gulf air overhead. Notable 
slug of PVA and a low level jet will result in widespread likely to 
categorical PoPs across the CWA for Thursday. Soundings do show 
diurnal increases in CAPE (1000-1500 J/kg), so expect a chance of 
thunderstorms Thursday afternoon into Friday morning. The low 
makes its way into the Great Lakes region by Friday afternoon 
allowing low to mid level ridging to build in over the region. This 
will decrease PoPs across the area, but still expect to see diurnal 
redevelopment of showers and slight chance of thunderstorms.

The Weekend...Upper low opens into a trough and exits NE allowing 
upper ridging to build in over the region. Will continue to maintain 
low level southerly flow with dew points in the 60s with our 
position on the western flank of high pressure. Warm southerly flow 
will push temperatures into the upper 70s to low 80s, giving us a 
late last look at summer with dry conditions expected. 

Monday and beyond...Models begin to diverge a bit during this period 
with regards to a Central Plains system and its depth and placement. 
But overall, expect to see rain and possible thunderstorms return 
during the beginning of next week.

&&

.Aviation...(00Z TAF Issuance)
Issued at 740 PM EDT Tue Oct 5 2021

Scattered to numerous showers, briefly moderate to heavy, are 
getting ready to lift northwestward through HNB/SDF/LEX over the 
next few hours. Could see some brief low MVFR or IFR visibilities if 
a heavier shower impacts a TAF site. BWG should be in the clear 
until after Midnight, outside of a few spotty showers.

Ceilings should remain VFR through the overnight. however some lower 
ceilings (MVFR) could impact BWG/HNB, and possibly SDF around or 
just after sunrise. LEX should remain VFR. Any MVFR ceilings in the 
morning are expected to improve again by later in the day.

Periods of showers will again work S to N over the area tomorrow, 
with potential for reduced visibilities, and perhaps a few 
thunderstorms in the afternoon. Confidence is medium on timing and 
impacts.


&&

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

$$

Update...BJS
Short Term...RAS
Long Term...CG
Aviation...BJS