


Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
606 FXUS63 KLMK 121759 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 159 PM EDT Sat Jul 12 2025 ...Updated Aviation Discussion... .KEY MESSAGES... * A few strong to severe storms possible later this afternoon and evening, especially across southern Indiana and northern Kentucky. Locally damaging winds, small hail, and brief heavy rainfall are the main threats. * Warm and humid with continued chances of showers and storms through Sunday. Gusty winds, heavy rainfall and lightning will be the main impacts but some storms could produce small hail and gusty damaging winds. Locally heavy rainfall amounts are possible. * Remaining very warm and humid for most of next week with more scattered rain and storm chances each day with heavy rain, gusty winds and lightning. && .SHORT TERM /THROUGH TONIGHT/... Issued at 258 AM EDT Sat Jul 12 2025 Things are quiet across the CWA early this morning, and that will continue for much of the morning, if not all of it. Thereafter, focus shifts upstream to an approaching cold front and the reintroduction of scattered showers and thunderstorms for the afternoon through late evening. Currently, a weakened complex is dissipating across central IL/MO, and we`ll likely only see some upper sky cover/anvil debris from it. The other feature we`ll have to keep an eye on is the remnant outflow that is currently making steady SE progress toward our area. This may indeed be a focus for initiation later today once we destabilize. Different hi-res models have different thoughts about that. For instance, the 12/00z 3 km Nam has a pretty reasonable solution of scattered showers and storms initiating to over the center of our CWA between Noon and 2 PM EDT on that remnant outflow, and then a secondary area of convection developing much later in the afternoon and early evening ahead of the approaching cool front and pre-frontal trough. Ahead of these features we do expect to destabilize fairly quickly as temperatures reach into the upper 80s and low 90s amid low to mid 70s dew points. This should yield moderately unstable ML CAPE values around 1500 to 2500 J/KG. Do expect we`ll see some stronger storms given the amount of instability and a couple of triggering mechanisms, however the limiting factor to a more organized severe weather threat is the lack of deep layer shear. It only looks to be around 15-20 knots in the 0-6km layer which would be sub par for more sustained/organized updrafts. Still, given the amount of instability and the potential for some water loaded microbursts and/or a cold pool push from collapsing storms, do think a couple severe thunderstorms warnings aren`t out of the question. Marginal Risk covers the threat nicely, and the upgrade to a Slight Risk over southern IN and far northern KY seems to mimic the 12/00z 3 KM Nam fairly well. Given the plausibility of that scenario think it looks pretty good. Right now, the biggest threat for severe storms looks to be between 5 and 11 PM EDT. Convection should diminish into the overnight, however given the surface front still dropping into our area, can`t rule out a few stray showers and storms overnight. Look for mild temps in the low and mid 70s for most. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 258 AM EDT Sat Jul 12 2025 Sunday - Monday... A baggy shortwave trough axis over the eastern CONUS will slowly slide through Sunday. Meanwhile at the surface, a cool front will slide into our area. Ahead of these features, moderate instability on the order of 1500-2500 J/KG of ML CAPE is expected to develop. This setup has plenty of ingredients for numerous showers and thunderstorms in the moist and unstable atmosphere. There continues to be a weak signal for deep layer shear only around 15-20 knots, however do expect we could get a few pulse storms strong enough to produce some gusty downburst winds, cloud to ground lighting, and brief heavy rainfall. In fact, the bigger concern will likely be the locally heavy rain threat given slow moving thunderstorms and PWATs approaching 2" through the column. SPC dropping the Marginal Risk is noted, although expect a couple of strong to severe storms can`t be ruled out; especially given the little extra nudge of forcing compared to our recent pulse environments from last week. The upper trough axis slowly moves eastward by Monday, however the weak surface front is left lagging across southern and eastern portions of our CWA. As a result, will keep lingering pops in for this area on Monday with highs a tick cooler in the upper 80s and low 90s. Tuesday - Friday... The SE CONUS upper ridge tries to build in for the mid week time frame, however a weak disturbance looks to ride the NW periphery of that feature, and could bring additional showers and storms to our area for Tuesday and Wednesday. From there, mainly diurnally driven shower and storm chances are likely to continue into late week as our region remains positioned on the northern fringes of the SE CONUS ridge, and on the southern fringes of the stronger westerlies associated with a zonal flow aloft pattern. This will keep us in line for any weak triggering mechanisms embedded in the flow, and on the edge of the upper ridge where the subsidence inversion is weaker. All of this supports at least some diurnally driven shower and storm chances each afternoon and evening. Temps will likely be slightly above normal for this time of year with highs peaking in the upper 80s and low 90s. Any early convection each day could knock temps down, but will likely reach low 90s by early afternoon with scattered PM storms providing some spotty relief from temps at times. && .AVIATION /18Z TAFS THROUGH 00Z MONDAY/... Issued at 158 PM EDT Sat Jul 12 2025 A mid-level shortwave is working across parts of IL and IN this afternoon. Scattered mid-level Cu has been forming along with scattered to isolated showers and storms. These storms are expected to become more numerous in nature. The main time for this activity will be between now 18z through about 01/02z as they quickly move across the area. It is possible some of this activity diminishes before it reaches LEX/RGA. Overnight we should remain with VFR flight categories with LEX/RGA seeing a period of high MVFR CIGs around 2500 Ft towards sunrise tomorrow. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...BJS LONG TERM...BJS AVIATION...BTN