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
123 FXUS63 KLMK 030830 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 330 AM EST Tue Nov 3 2026 .KEY MESSAGES... * Widespread rainfall tonight into Wednesday will benefit the ongoing drought. Amounts of 1 to 1.75 inches will be most common, though a few locations (10% chance) may see totals surpass 2.5 inches. The risk of flooding is low. * The risk for severe weather is low, though brief and localized gusty winds exceeding 40 mph may (20-30% chance) accompany showers tonight into tomorrow. && .DISCUSSION... Issued at 328 AM EST Tue Nov 3 2026 *** Warm and pleasant today *** Early Tuesday morning, the area is situated between high pressure over the Mid-atlantic and a large, upper-level low pressure system across the Great Plains. Between these two features, a tight surface pressure gradient will favor 10-20 mph winds out of the south- southeast, with a few gusts approaching 30 mph at times late morning through the afternoon mainly near and west of the I-65 corridor. Coupled with morning sunshine, this will warm temperatures into the mid to upper 70s area-wide this afternoon, with a few spots potentially topping 80. The National Blend of Models (NBM) gives the highest chances (30-50%) for 80+ degree highs today south of a roughly Tell City to Berea line. Meanwhile, clouds will increase from west to east during the afternoon as an increasingly moist airmass overspreads the region ahead of the aforementioned Great Plains low. *** Breezy with beneficial rain tonight into tomorrow *** A 55-65 kt 850mb LLJ will overspread the local area tonight, strengthening moisture advection and sparking scattered showers after around 10pm EDT. With HREF mean bringing PWAT values into the 1.6-1.75 inch range (95-99th percentile of climatology), a seasonably deep (10-12 kft) warm cloud layer, and cloud-bearing layer winds nearly parallel to the eastward-moving front, the set up will be favorable for some training heavy showers and, hence, swaths of hefty rainfall totals late tonight into tomorrow morning. LPMM places these highest amounts (2-3+ inches) roughly along the I-65 corridor, which is where NBM`s probability for more than 2 inches of rainfall is also maximized at 20-40% (highest south of E-town). This should be a beneficial rain for most if not all of the area given ongoing drought conditions, but we can`t completely rule out an instance or two of nuisance flooding given (1) most of this rain will fall in a 4-6 hour period, (2) River Forecast Center (RFC) 6- hour Flash Flood Guidance (FFG) is around 3 inches, and (3) the antecedent dry conditions may have led to some crusting over of the ground which would increase initial runoff; in addition, urban areas may be more prone to problems if any storm drains are clogged with leaf debris. While kinematics appear impressive overnight tonight into tomorrow morning, with the GFS depicting 45-60 kt (highest west) of 0-6km bulk shear, two things will be working to limit the potential for severe weather: (1) instability will be limited with the HRRR/NAMNest only depicting 200-500 J/kg (elevated) MUCAPE, and (2) forcing will be weakening along the cold front as the low occludes over the Upper Midwest. Still, just enough of this instability may poke into the hail growth zone (HGZ) to spark a lightning strike or two in the stronger cells; but even without robust convective updrafts or lightning, the intense environmental synoptic-scale flow could be transferred to the surface to produce localized strong wind gusts exceeding 40 mph. Since this should be both isolated in nature and tied to showers, a Wind Advisory will not be needed, though a few convective Special Weather Statements (SPSs) may be. With the cool front`s eastward progression slowing down, the rain and locally/sporadically gusty winds will linger into the afternoon tomorrow, perhaps not winding down until after sunset across parts of the Bluegrass. Conditions will turn slightly cooler behind the front, though low level moisture will linger amidst continued cyclonic flow and we may see some drizzle tomorrow evening into tomorrow night. *** Turning seasonably cool this weekend *** The next system will have considerably less moisture to work with, and will only bring the area 10-20% chances (highest north) for measurable rainfall during the day on Friday. However, temperatures are currently forecast to turn a bit cooler in its wake. Though confidence remains low on how much we cool down and how long it lasts with the northern stream jet largely remaining north over the Great Lakes, at the very least we can expect some chilly overnight lows given the drier airmass. NBM probabilities for cooler than 36 degree overnight lows are running at 50-70% across the area (except lower chances in urban cores) both Sunday and Monday nights, suggesting we may see frost. && .AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 1214 AM EST Tue Nov 3 2026 A potent storm system over the Great Plains will bring marginal LLWS to mainly the HNB, SDF, and BWG airfields early Tuesday morning as winds at just 1500 ft reach 35-40 kt. Southerly surface winds will increase sharply - to 10-15 kt with gusts to around 20 kt - after around 14z, reducing the LLWS significantly. Near the end of the TAF period, a stronger low level jet will develop, resulting in another round of LLWS, numerous showers (possibly with a rumble of thunder as well), and lowering ceilings. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ DISCUSSION...JRB AVIATION...JRB