textproduct: Jackson

KEY MESSAGES

- Cool and mainly dry weather will prevail through the weekend.

- Frost is increasingly likely late Saturday night and early Sunday and could be extensive in valleys.

- The next area-wide potential for showers and thunderstorms will be Monday into Thursday.

UPDATE

Issued at 958 PM EDT THU APR 30 2026

While the previously-discussed cloud cover is beginning to creep into the forecast area, observed temperatures have continued to outpace the modeled diurnal cooling curve this evening. After blending this quicker downward trend into the forecast grids, overnight temperatures were bumped down in the sheltered and shaded valley locales northeast of the KY-15 corridor. Upstream cloud cover is not particularly thick or widespread at the moment, but guidance continues to resolve increasing sky cover around the 10,000-20,000 ft AGL layer tonight. This may eventually mute the magnitude of the observed cooling, but it is becoming increasingly likely that the hollows of Eastern Kentucky will see MinTs in the 30s tonight. Patchy frost has been added to the grids, but interests should note that this is contingent upon the clouds continuing to under-perform previous insulation expectations. The rest of the forecast remains on track, and a cold frontal passage tomorrow will yield more widespread frost potential later this weekend.

UPDATE Issued at 640 PM EDT THU APR 30 2026

The previous forecast remains on track this evening, with diurnal cumulus clouds beginning to decrease in coverage in the latest satellite imagery. A few high clouds are currently streaming across the KY-30 corridor, and midlevel cloud coverage is resolved upstream along the KY/TN border. The thicker upstream clouds should spread northeast into the forecast area overnight as a disturbance approaches, but there are some breaks observed within them at the moment. If those breaks persist later this evening and valleys are accordingly able to decouple, adjustments may be necessary to tonight's MinT grid. Hourly temperatures are already running a couple of degrees colder than observations, but since the thicker cloud cover is still forecast to build in from the SW after sunset, no major adjustments were made to the MinT grid yet. Rather, a quicker cooling trend was introduced in the hours surrounding sunset, and we will continue to monitor satellite trends as the evening progresses.

LONG TERM

(Saturday night through Thursday) Issued at 425 AM EDT FRI MAY 1 2026

The long term period will feature persistent upper level low pressure over southeast Canada with troughing extending southward over the eastern CONUS. The various waves/impulses rotating through the trough and morphing it will determine our day to day weather. The pattern will also favor below normal temperatures, at least initially.

One of the waves moving through the large scale trough is expected to be passing over on Saturday evening and departing to the east overnight. Moisture will be very limited, but even so, with very cold air aloft, models generate a few diurnal showers over western and central KY which last into the evening. Our surface dew points should be slightly lower (upper 20s to low 30s as opposed to mid 30s further west), and by the time the wave approaches the JKL forecast area peak heating will have also passed. That being the case, our forecast is dry, with only some clouds from the wave carrying into the evening. As the wave departs to the east, clouds should decrease Saturday night. With surface ridging building in from the west, winds will be light on Saturday night. With that setup, it still appears that frost will affect many places by dawn on Sunday. LREF probabilities for temperatures colder than 37F range from 40 percent near Lake Cumberland to 90 percent in eastern and northern locales.

The surface ridging slips to our southeast early in the new week and more impulses move through the flow in the upper trough. These will work to deepen the trough and send another cold front southward. The flow between the high/ridge to our southeast and the approaching cold front will give us increasing southwesterly winds and warm air advection early in the new week. Moisture off the Gulf should also work its way around the periphery of the high ahead of the cold front, supporting showers/thunderstorms with the front. The main issue for our area will be the timing and evolution of the front and its precip, with models not united on this. The most likely time for significant widespread precip is in a window from Tuesday night to Wednesday evening, but the forecast remains rather generalized at this point due to the uncertainties. Some spottier precip can't be ruled out earlier in the new week, but support and moisture look to be more limited this far south until the main cold front approaches. Behind the cold front, more waves passing through the upper trough are expected to continue deepening it, and this could still bring lighter showers to our area on Thursday.

AVIATION

(For the 06Z TAFS through 06Z Friday night) ISSUED AT 202 AM EDT FRI MAY 1 2026

VFR conditions will prevail for the duration of the 06Z TAF period. Midlevel clouds will pass through the remainder of the pre-dawn hours, although more widespread cloud coverage is expected during the day as a weak front moves through. There will be a low chance of rain showers associated with the front, so PROB30 groups were retained for our far northeastern terminals. Any precipitation that falls should remain light, so visibility reductions are not anticipated. Winds will be light and variable through dawn. During the day on Friday, winds will initially be southwesterly but become more northwesterly following the frontal passage. Cloud cover will linger following the frontal passage, but will remain solidly VFR.

JKL WATCHES/WARNINGS/ADVISORIES

None.