723 
FXUS63 KLMK 130145
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
945 PM EDT Fri Jul 12 2024

.KEY MESSAGES...

*   Mostly dry weather and warming temperatures expected for for the 
    weekend. 

*   Triple-digit heat index values could return Sunday afternoon and 
    are likely early next week.

*   Shower and storm chances look to increase by the middle of next 
    week as a frontal boundary sinks into the area.

&&

.UPDATE...
Issued at 943 PM EDT Fri Jul 12 2024

This evening an MCV spinning over southern Missouri spawned a few 
storms over the region which brought some heavy rain and gusty winds 
up to 30mph. An impressive cold pool developed with these storms, 
clearing all cumulus as it gusted out. Quite an interesting satellite 
display this evening. Currently, quiet conditions over the region, 
which will stick around through the overnight hours. Calm to light 
winds and clear skies will allow for some fog development in the 
early morning hours. Could become dense in some areas, specifically 
within the river valleys or areas that received rain this evening. 
An SPS may be needed with the overnight forecast package once fog 
begins to form. Otherwise, Saturday will be mostly sunny with 
diurnal cumulus development in the afternoon. Temperatures will be 
warm in the low-mid 90s.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 311 PM EDT Fri Jul 12 2024

A clearly defined MCV is rotating into the MO Bootheel at this hour, 
and will continue to trigger isolated to widely scattered convection 
across western KY late this afternoon into early evening. Some of 
that additional convection could survive into our W through around 
sunset. Meanwhile, isolated convection across our area has kicked 
off late morning into the early afternoon, with chain reaction 
outflow kicking off additional coverage. Overall, storms have 
remained relatively weak and short-lived given the lack of deep 
layer shear, and very poor mid level lapse rates (less than 5.5 
C/KM). A few storms have gotten a bit strong mainly along and west 
of I-65 where lightning and gusty outflow have been noted. 

Expect that H6 subsidence inversion will remain in place through the 
evening, and given that don't expect storms to get too strong. It is 
fairly unstable as ML CAPE values will likely peak in the 1500-2000 
J/KG range, but again the mid level inversion, poor mid level lapse 
rates, and lack of stronger deep layer shear are all limiting 
factors. A couple of SPS statement for gusty winds to 40 mph are 
still possible through sunset, before we lose heating/instability.

Looking for convection to die off in the evening with the loss of 
heating, and a relatively quiet overnight. Temps should be a bit 
milder than last night with lows in the upper 60s and low 70s for 
most. Seems like a fairly good setup for some patchy fog development 
overnight, and will have to assess late afternoon crossover Ts for 
whether we think we could have any dense fog potential. Right now, 
guidance likes the idea of fog, but isn't too aggressive with dense 
fog. Some uncertainty with upper sky cover hurts confidence a bit in 
just how widespread/dense it may become.

Looking for another hot, humid, and mostly dry day on Saturday. 
General troughiness remains over the area, but overall this will be 
a pretty weak mechanism for triggering. Will carry some isolated 
pops across western CWA first of the day, but gradually drying out 
through afternoon. Given less convection, expect temps to warm a 
degree or two from today. This puts most locations a bit more 
solidly into the low 90s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 311 PM EDT Fri Jul 12 2024

Sunday - Tuesday

Upper level ridging will remain to our west, with more zonal flow 
expected across the eastern half of the US. This pattern will 
promote a mostly dry forecast, with the exception of an isolated 
shower or storm possible for a few hours north of the Kentucky 
Parkways Sunday afternoon. Otherwise, hot and dry weather will be 
the story as sfc high pressure holds it's position to our east. 
Temperatures are forecast to rise into the upper 90s each day, with 
Monday possibly being our hottest day of the forecast period. 
Dewpoints will be in the upper 60s and low 70s, which will translate 
to heat indices between 100-105F. Practice heat safety in the coming 
days by drinking plenty of water, taking breaks indoors, checking on 
vulnerable neighbors, and never leaving children or pets in a 
vehicle unattended. 

There will be little relief during Sunday night and Monday night, 
with temps expected to remain in the 70s. Monday night may even 
feature some mid- to upper-70s in the urban areas. 

By Tuesday afternoon or evening, we may begin to see PoPs return to 
the area ahead of an approaching cold front. The driving upper 
trough will remain well north, but the associated cold front will 
be diving southward from the upper midwest into the lower Ohio 
Valley. An increase in RH along with some weak mid-level forcing 
ahead of the front may result in some isolated precip activity late 
in the day, but the primary rain chances will come with the front on 
Wednesday. 


Wednesday - Friday 

Best shower and storm chances will be on Wednesday as the cold front 
passes through the region. As of now, model soundings show a 
marginally unstable airmass, with weak shear and mostly 
unidirectional flow. PWATs approaching 2 inches will support heavy 
rain rates, but confidence on any organization and severe potential 
remain low at this time. Will be something to keep an eye on in the 
coming days. 

After FROPA, PoPs will linger as the front slowly shifts to our 
south. Will keep PoPs going into the end of the week as well, though 
chances will not be as high as Wednesday. Temps should rebound to 
near-normal for both Thursday and Friday, with highs in the mid- to 
upper-80s.

&&

.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 735 PM EDT Fri Jul 12 2024

Winds are beginning to relax and skies are thinning. With these 
conditions remaining overnight, fog will begin to develop in the 
early morning hours and last until around 12-13Z. Conditions will 
likely remain MVFR but could dip into IFR for a time. On Saturday, 
light winds out of the west will prevail with diurnal Cu in the 
afternoon.

&&

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

&&

$$

UPDATE...SRM
SHORT TERM...BJS
LONG TERM...CJP
AVIATION...SRM