textproduct: Jackson

KEY MESSAGES

- Clear skies, light winds, dry air, and overnight lows in the mid to upper 30s favor the development of frost in sheltered hollows tonight. - A warming trend begins Friday with afternoon highs returning to the mid 70s to low 80s by Sunday.

- Periodic chances for showers and thunderstorms return to the area this weekend, with the greatest chances on Sunday night.

UPDATE

Issued at 900 PM EDT THU MAY 7 2026

00Z sfc analysis shows high pressure now in control of the weather over eastern Kentucky. This is working to settle the winds and keep skies clear along with allowing the drier air to seep deeper into this part of the state. As a result, we now expect temperatures to get a bit cooler in the valleys and allow for more extensive frost. Consequently, have issued an NPW for a frost advisory from midnight until 9 am for the southeast 2/3rds of the area. An SPS addresses more patchy fog for the rest of the JKL CWA. Currently, temperatures are running in the mid to upper 50s. Meanwhile, amid those light winds, dewpoints continue to fall and now vary from the upper 20s northwest to the lower 40s in the far southeast. Have updated the forecast to adjust low and hourly temperatures through the night and extend the frost impacts. Did also add in the latest obs and trends for the T/Td/Sky grids. These adjustments have been sent to the NDFD and web servers along with a freshening of the HWO, SAFs, SPS, and zones.

LONG TERM

(Saturday through Thursday) Issued at 430 PM EDT Thu May 7 2026

The beginning of the long term forecast period is marked by the approach of a weak frontal boundary. A few showers may be ongoing north of the Mountain Parkway when the period opens on Saturday morning, but the environment will be more hostile to sustained activity the further southeast it tracks into our CWA. Model soundings demonstrate a layer of very dry air in the atmospheric column over SE KY, and this gets reinforced by a pronounced subsidence inversion on Saturday afternoon. The boundary's upper level support ejects east and abandons it around this same time frame. Thus, while some remnant cloud cover and perhaps some sprinkles will drift through the region on Saturday, the day does not look like a total washout. The greatest chances for measurable precipitation on Saturday will come in the NE half of the forecast area, and even then, the lack of strong forcing and the dry air will relegate QPF to a few hundredths of an inch. While Saturday's temperatures could trend a little bit cooler if precipitation and cloud cover begin to outperform current expectations, highs are forecast to peak in the mid 70s under partly cloudy skies that afternoon.

Surface high pressure briefly builds back into the region on Saturday night, setting up a night of ridge-valley temperature splits. The lack of true cold air advection behind Saturday's boundary keeps modeled temperatures at seasonable values in the 50s, but clearing skies and light winds should yield efficient radiational cooling. After sunset, valleys cool into the 40s and approach the antecedent dewpoint temperatures. Given this set up and the potential for recently wet grounds, patchy river valley fog was added to Saturday night's grids with this afternoon's forecast package. Ridgetops and western locales will be relatively warmer thanks to light west-southwesterly winds, with MinTs in the low to mid 50s. Some of today's MOS guidance is more aggressive with the magnitude of these ridge-valley splits, and if that persists, future packages may feature 10-15 degree terrain-based temperature differences on Saturday night.

Sunday looks to be the warmest day in the forecast period, with temperatures climbing towards the upper half of the 70s after the sun comes out. This warmer air supports more widespread shower and thunderstorm chances ahead of a better defined frontal passage on Sunday night. LREF mean PWATs climb to readings just above the 1 inch mark across the entire commonwealth on Sunday evening, which is about a quarter of an inch higher than the day prior. Thus, more places across the forecast area should experience measurable rainfall on Sunday than on Saturday. The greatest precipitation chances arrive overnight into Monday, when instability will be at diurnal minimums. Widespread severe weather appears unlikely as a result, but generic thunderstorms will be possible. The highest rain totals will come wherever these individual storm cells track, but there is a 50-60% chance for a wetting rainfall (>0.10 inches) across the entire forecast by 8am Monday.

There will be more noticeable cold air advection behind Sunday night's frontal passage, and Monday is subsequently poised to be the coolest day of the forecast period. Highs will struggle to warm above the mid 60s as vertically stacked northwesterly flow advects a drier continental airmass into the forecast area. Models collectively resolve a deeper midlevel trough axis over the forecast area on Monday afternoon, so this NW flow regime looks to continue overnight into Tuesday. With a postfrontal high in place at the surface, Monday night's sensible weather will likely be elevation dependent. Depending on how wet grounds are from the previous day's activity, the nocturnal radiational fog could be more widespread than it was earlier in the period. This is not currently included in the forecast grids, but may make an appearance in future packages. Given the progressive nature of the overarching synoptic pattern, winds are progged to steadily shift to a more southerly orientation by Tuesday night. MaxTs are accordingly forecast to rise to the upper 60s on Tuesday afternoon and then the 70s area wide on Wednesday. This midweek warming trend coincides with the arrival of the next shortwave troughing disturbance in the Ohio River Valley. Therefore, shower and thunderstorm chances re-enter the forecast on Tuesday and Wednesday, although uncertainty regarding the evolution of the parent impulse relegates these PoPs to the 30-50% range.

AVIATION

(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 820 PM EDT THU MAY 7 2026

A shallow cu field has just about dissipated this evening with the loss of diurnal heating. For tonight, high pressure cresting over the area will lead to light winds and clear skies. Fog formation is probable in the deeper river valleys but impacts are not currently expected at the TAF sites leaving them VFR. Expect winds to remain light and variable through the period, as well.

JKL WATCHES/WARNINGS/ADVISORIES

Frost Advisory from midnight tonight to 9 AM EDT Friday for KYZ068-069-079-080-083>088-106>120.