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KEY MESSAGES

* Isolated to scattered showers and storms will continue this afternoon in the southern CWA. Still monitoring the low-end flash flood concerns for stationary heavy downpours across our southern border counties.

* An organized cluster of storms will move across our far SW counties, bringing gusty winds and heavy downpours. Isolated areas could see 1-2", though most of the SW have a 75% chance of <0.5" rainfall totals.

* Dry and comfortable weather is expected through the middle of the week before moisture increases by next weekend. Shower and storm chances return next weekend and into early next week.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 336 PM EDT Sun May 31 2026

Today and Tonight...

A weakening high pressure over the Great Lakes is allowing low level moisture to build in from the southwest. Currently, we're monitoring some showers around the CWA and a storm or two just south of the TN border. With little steering flow or shear, anything that pops up will be slow-moving later this evening. A stationary boundary providing weak convergence over the CWA will help trigger isolated showers as well, though not much rainfall is expected today. Good news is that SBCAPE values are generally under 1000 J/kg, and with effective bulk shear at or below 20 kts, showers and general thunderstorms are expected bringing lightning and heavy downpours.

While there is no severe threat, a marginal risk for excessive rainfall spans across our southern border counties next to TN in case of a slow-moving heavy downpour. HREF 3hr PMM data suggests a 30-50% of exceeding 1", though the ground there should handle rates like this well considering the ongoing drought. Otherwise, spotty showers or a stray storm will continue until sunset when we lose the energy from daytime heating. After sunset, clouds generally clear overnight with temperatures settling into the upper 50s to the low 60s.

Monday - Monday Night...

With at least some clearing overnight, dew points rising into the mid 60s or higher in some southern areas creates the potential for fog, mainly SW of the Natcher and Cumberland Parkways. Elsewhere, the surface boundary never quite makes it through the rest of the CWA, remaining fog free. Shortly after sunrise, mid-level clouds increase from SW to NE ahead of an approaching QLCS from central Illinois. This will sink SE, clipping our western/southern counties by late morning near lunchtime. Latest HREF guidance suggests the strongest storms will be following a SBCAPE gradient outside of our CWA. That being said, there may still be enough instability for storms to tap into creating strong to severe gusty winds, lightning, and locally heavy downpours. A Marginal Risk barely clips Logan County, with the greatest potential for severe weather remaining too far SW of the CWA. Regardless, a line of light to moderate rain will move through western areas by late morning to the early afternoon hours, with leftover showers for the rest of the area in the evening. A second wave of showers is possible late Monday night, though there is uncertainty with how much rain would fall as dry air from the north will be moving further into the CWA by then.

Rainfall totals Monday are higher in the SW and right-skewed dependent on the location and strength of the weakening storms in the morning. Across the SW CWA from Hancock County and SE towards Clinton County, 25-75th percentile rainfall ranges ~0.1 - 1.25". This indicates the uncertainty with how well the QLCS handles nocturnal cooling with modest skinny CAPE and low shear when moving over our area. Should nocturnal cooling prevail, the QLCS will weaken quickly and bring general showers to the SW. This will continue to be monitored throughout the evening. Additionally, HREF LPMM guidance is suggesting 1-3" totals in isolated areas is possible should stronger storms move through later in the morning through the early afternoon in the SW, where isolated flash flooding may occur. For now, expect rainfall totals of 0.25-0.5" across this area, with up to 0.25" elsewhere. By Monday night, surface high pressure returns with a NE flow cooling temperatures into the mid to upper 50s. PWATs decrease as well, dropping to the 20th percentile or lower by Tuesday morning.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 336 PM EDT Sun May 31 2026

Tuesday through Friday...

Today's medium range guidance continues to show a relatively dry and warm pattern setting up for the Ohio Valley for much of the week. Aloft, a blocky flow pattern will persist across the CONUS with a large ridge over the upper Midwest into the Great Lakes and Ontario with downstream troughing across the northeastern US coast. The troughing across the NE US coast will continue to deepen and we'll likely see a closed upper low form off the Carolina coast while large scale ridging holds sway across the lower MS Valley northeastward through the Ohio Valley and into the Great Lakes. At the surface a very strong areas of high pressure will be in place across the region. The ensemble means show our MSLP fields will be above the 99th percentile based on early June climatology.

With the ridge overhead, PWAT values will decrease markedly on Tuesday with low humidity values remaining in place for the remainder of the week. With such low moisture values, the forecast continue to remain dry in the Tuesday through Friday period. Given the strong high pressure, it will be quite breezy on Tuesday across the region, but as the high moves overhead, we'll see winds slacken up a bit for Wed-Fri. With mostly sunny days and mostly clear nights expected, diurnal temperature ranges will be quite large for early June. Highs Tuesday and Wednesday will be in the upper 70s to the lower 80s with overnight lows in the 50s. A few of the typical cool spots may be able to dip into the upper 40s Wednesday morning. By Thursday and Friday, we'll get back into a southerly flow and temperatures will start to warm up. Highs Thursday and Friday should warm into the 80-85 degree range with overnight lows in the upper 50s/lower 60s.

Saturday through Sunday...

Moving into the weekend and into next week, the upper flow pattern will become less blocky. The ongoing ridging across the Ohio Valley is forecast to shift east-southeast while a short wave trough axis moves out of the four corners region into the southern Plains. The southeast ridge looks to hold sway keeping the Ohio Valley on the western periphery of the ridge axis. Shortwaves coming out of the southwest will take a track across the southern Plains and into the Midwest while a plume of deeper Gulf moisture will be advected north through the lower MS Valley and then northeast into the TN/OH Valleys. Episodic bouts of showers/storms look to train across the region in the late Saturday through through Sunday time frame. Additional rounds of convection are likely into early next week as the flow pattern remains rather steady state. It is possible that a period of excessive rainfall could occur late next weekend and into next week. Despite the clouds and precipitation, temperatures are likely to average near normal for the period.

AVIATION /18Z TAFS THROUGH 00Z TUESDAY/

Issued at 136 PM EDT Sun May 31 2026

VFR conditions will continue through this afternoon as mixed high level clouds pass over. Light to calm winds will persist through the evening as well. Skies generally begin to clear overnight, albeit with a few high level clouds leftover. Increased surface moisture with clearing skies may produce patchy fog over BWG in the morning, including a TEMPO group there for foggy conditions just before sunrise. Otherwise, mid level clouds increase as a complex of weakening storms moves over our SW areas. Towards the end of the TAF period, rain will be more prevalent in BWG, with -SHRA or a PROB30 for -SHRA everywhere else by late morning into midday. Light NE winds return by the afternoon as VFR conditions persist through tomorrow.

LMK WATCHES/WARNINGS/ADVISORIES

KY...None. IN...None.