textproduct: Louisville

KEY MESSAGES

* Clearing skies combined with recent rain and saturated ground will lead to the development of patchy dense fog early this morning.

* Mostly dry through the weekend and into early next week. Low shower and storm chances across southern KY this weekend. Seasonable temperatures are expected.

UPDATE

Issued at 1046 AM EDT Thu May 28 2026

Morning fog has dissipated across the region with the low stratus field across the central CWA beginning to mix out as well. Winds have shifted to a light northeasterly flow behind the front as it continues to crawl southwest.

Dewpoints begin to gradually fall a couple degrees as we begin to dry out following the front, but not providing much of a relief from our humid conditions. Not many changes to this afternoon's highs: upper 70s to low 80s are still expected across the region under mostly sunny skies.

SHORT TERM /THROUGH TONIGHT/

Issued at 318 AM EDT Thu May 28 2026

Now through Mid-Morning...

Across the area this morning, there are a few lingering sprinkles and light rain showers located along a west-to-east line across central and eastern KY. These showers are located along a wind shift line with light northeast winds across the northern half of KY and southern IN while generally calm/variable winds are observed in southern KY. Any lingering showers/sprinkles are expected to dissipate over the next few hours.

The other thing we're monitoring this morning is patchy fog, some of which has been dense across southwest OH, central IN, and northern KY. Across our CWA, dewpoint depressions are only a degree or two (or less) in many locations, with muggy conditions continuing behind the northerly wind shift. While instances of fog have been relatively patchy so far across the area thanks to lingering low-to- mid level cloud cover, low clouds are expected to decrease from NE to SW over the next few hours, allowing for some boundary layer decoupling. 0Z HREF probabilities of less than 1/4 mile visibility increase from NE to SW between now and sunrise, suggesting the potential for dense fog, though probabilities remain less than 50% in most areas. As a result, think an SPS, possibly even a small dense fog advisory may be needed within the next few hours, though we'll just monitor traffic cameras and AWOS/ASOS obs for now. Temperatures are expected to remain fairly steady in the mid-to- upper 60s between now and sunrise.

Late Morning through This Afternoon...

Once the sun rises, surface heating should allow sfc moisture to mix out, with drier air aloft allowing fog to completely dissipate by around 13-14Z. While this moisture may develop into a brief stratus layer during the late morning hours, continued dry air from high pressure over the Great Lakes should support clearing skies by midday, with mostly sunny skies expected by mid-to-late afternoon across much of the area. Northeast winds of 5-15 mph from low-level anticyclonic flow are expected during peak heating, keeping temperatures slightly below persistence, with highs in the low-to- mid 80s. Continued dry air advection should limit precip chances today, though an isolated sprinkle or show can't be completely ruled out, especially in southern KY.

This Evening and Tonight...

Surface high pressure should sink into the LP of Michigan and Ohio this evening into tonight, with higher sfc moisture continuing to be swept off to the south and west as the high approaches. While temperatures won't be noticeably cooler during the day today, drier air (especially in the KY Bluegrass region) should allow for more radiational cooling and lower minimum temperatures Friday morning. Expect a range in lows from the low 60s across southern and southwest KY to the low-to-mid 50s across southeast IN and northern KY. A few upper 40s can't be ruled out in the cooler valleys in the Bluegrass. Would not expect fog to be prevalent tonight given the drier air and a persistent NE breeze, and HREF probabilities of sub- 2 mile VIS is less than 10% across the area.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 318 AM EDT Thu May 28 2026

Synopsis...

Ensemble 500 mb height fields depict a quite amplified synoptic pattern from the end of this week into at least the first half of next week. Ridging currently over the central CONUS and Canada is expected to amplify this weekend into an omega blocking pattern with troughing expected over the north Pacific Ocean and the Canadian Maritimes. As is typical for blocked flow patterns, this pattern is expected to persist for a while through at least the first half of next week, before guidance suggests the block will begin to break down and a more zonal/progressive pattern is favored to return by the end of next week.

At the surface, the strengthening upper level high should lead to anticyclogenesis over Ontario and the Great Lakes region, with the southern edge of this persistent high pressure feature extending into the Ohio Valley over the extended forecast period. Divergent and anticyclonic flow out from the center of this sfc high should provide bouts of north and northeasterly flow, advecting drier and somewhat cooler air into the region. Through the weekend, the gradient between drier air to the north and humid air to the south will be close enough to the region for continued chances for daytime shower/storm chances, with the highest chances being across southern KY. A stronger push of northerly, drier flow early next week will favor dry conditions for most if not all the region for the first two-thirds of next week.

Friday through Sunday Night...

While Friday should begin with dry conditions and lower dewpoints across the area, a descending upper shortwave on the western edge of the low over southeast Canada will cause some modest return flow from the TN Valley into southern KY. At this time, there should be enough moisture return to re-introduce a chance for garden-variety showers and storms across southern KY Friday afternoon into Friday night. As the upper wave pushes to the southeast during the day on Saturday, another surge of drier air from the northeast should push low chances (20-30%) for precipitation back along the KY/TN border by Saturday afternoon and evening. After another round of drier conditions Saturday night into Sunday morning, a secondary shortwave associated with the larger southeast Canada low will allow for another episode of moisture return into southern portions of the CWA and a low chance for showers and possibly a storm Sunday evening into Monday morning.

While the LREF probabilities for measurable precipitation reach 30- 60 percent on several occasions between Friday and Monday, the probabilities for greater than 0.10" are much lower (5-25 percent), and substantial rainfall amounts are unlikely. Temperatures through the period will be relatively seasonable, with a NE-SW gradient expected (cooler to the NE) across the area.

Early to Mid Next Week...

Following the late weekend disturbance, upper troughing should become more established over the northeast US early next week, with stronger sfc high pressure sinking into the region from the north Monday into Monday night. This allows for more widespread negative (dry) PW anomalies to settle into the region Tuesday into Wednesday, pushing the moisture gradient down into the Gulf states. Accordingly, precipitation chances drop for much of next week, with less than 10 PoPs featured in the current forecast from Tuesday through Thursday. Temperatures are expected to remain near or slightly below normal, with highs in the upper 70s and low 80s and lows in the 50s and low 60s.

AVIATION /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 749 AM EDT Thu May 28 2026

Current satellite imagery shows an area of low stratus slowly advecting into eastern and central KY, resulting in CIGS mostly between FL002 and FL004 and currently affecting LEX and RGA. Fog is also patchy across the region this morning with VIS bouncing from IFR to VFR at BWG and HNB. Fog should dissipate quickly as the sun rises, but the stratus will likely persist into the mid morning hours, with CIGs rising slowly before scattering out. By 15Z, VFR conditions should become predominate and continue throughout the rest of the TAF period. High pressure centered over the Great Lakes will result in winds out of the NE today around 6-12 kts. Drier air advecting into the region from the north should preclude any fog or stratus development for Friday morning.

LMK WATCHES/WARNINGS/ADVISORIES

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