textproduct: Jackson

KEY MESSAGES

- Isolated instances of frost are possible late tonight into Tuesday morning in deeper rural valleys and hollows - mainly away from mainstem rivers. There is a higher potential for frost formation Thursday night into Friday morning behind a cold front passage Wednesday. - A cold front is expected to bring chances for showers and perhaps a few thunderstorms for Wednesday.

- Additional shower and thunderstorm chances arrive this weekend accompanied by a trend of increasingly warmer temperatures into early next week.

LONG TERM

(Tuesday night through Sunday) Issued at 420 AM EDT MON MAY 11 2026

The start of the long term period will be defined by another frontal passage. A closed upper level low will be centered over the Great Lakes region, with high amplitude ridging over the western CONUS and a shortwave ridge over the northeastern US into Quebec. At the surface, an area of low pressure initially over northern Lake Michigan will translate eastward in correspondence with the upper level low, with an associated cold front draped south of this surface low pressure system. Ahead of the front, skies will be clear enough to allow for some decoupling Tuesday night, leading to a weak ridge-valley temperature split before clouds build in. Then, the cold front will push into our area overnight Tuesday into Wednesday morning, bringing a chance for showers and perhaps a few isolated instances of thunder across the forecast area. Overall, thunder chances will be modulated by the timing of the frontal passage; for now, most models favor a morning frontal passage with very limited instability, although the NAM delays the frontal passage until the afternoon, owing to a farther south upper level low delaying the breakdown of ridging over the northeastern CONUS. This slower front scenario would allow for marginally more instability, owing to additional diurnal heating, which would increase thunder chances and perhaps allow for convective enhancement of QPF, although this solution remains an outlier at this time. Ahead of the front, PW values will struggle to exceed 1 given a relatively dry prefrontal air mass; thus, QPF will likely remain low, with LREF median 24 hour precipitation confined to under 0.1 inches for most of the forecast area. By Wednesday night, the front will have departed the forecast area, with skies clearing overnight. This clearing will allow for another ridge-valley temperature split as high pressure begins to build behind the front and the pressure gradient decreases with time.

Thursday will be a tranquil, but cool weather day as high pressure dominates. Eastern Kentucky can expect mostly clear skies and weak CAA given northwesterly to northerly postfrontal winds. High temperatures will range from the mid 60s to perhaps the low 70s in some locations, approximately 5-10 degrees cooler than Wednesdays highs across the forecast area. A weak pressure gradient and clear skies overnight will create optimal conditions for efficient radiational cooling and a relatively significant ridge-valley split Thursday night, with GFS based COOP MOS guidance suggesting that many valley locations could fall into the mid to upper 30s. This would once again introduce a chance for patchy frost for sheltered hollows, although dewpoints may be a limiting factor in how far temperatures will fall on Thursday night; higher dewpoints in the source region would favor warmer lows and fog and thus a decreased frost risk, so dewpoint trends will require monitoring for future updates. Going into Friday, the surface high will continue to favor mostly clear skies, with winds becoming more southerly to southwesterly over the course of the day. This will allow highs to climb into the mid 70s, with modest moisture return initiating following the transition to southwesterly flow; this will keep minimum temperatures warmer on Friday night, although model guidance diverges with respect to cloud cover and precipitation overnight.

Looking into the weekend, model spread becomes quite high, and thus forecast confidence is very low. A closed upper level low will move onshore and into the southwestern US going into the weekend; however, there is little agreement regarding the position and effect of this feature, leading to intense model disagreement in the upper level pattern downstream. Many models are hinting that a more active pattern is possible over eastern Kentucky, but the timing and structure of any impulses remain unclear at this time. Accounting for the potential for multiple disturbances, the NBM has output low-end PoPs throughout the weekend; however, confidence remains low in this forecast at this time.

AVIATION

(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 129 PM EDT MON MAY 11 2026

VFR conditions are expected to prevail, with the exception of potentially locally dense fog tonight in many area valleys, which would be most likely to impact KSME and KLOZ. Fog also cannot be completely ruled out on ridgetops such as at KJKL, but is not mentioned in TAFs at this time.

Winds behind this morning's frontal passage will quickly back from northeasterly to northerly this afternoon, with winds expected at 10 kts or less, before decoupling around 00z this evening with the loss of daytime heating. Light west to southwest winds at 7 kts or less will develop beginning around 15z Tuesday with the onset of daytime heating/mixing.

JKL WATCHES/WARNINGS/ADVISORIES

None.