textproduct: Jackson

KEY MESSAGES

- A more active weather pattern will set up this week, with multiple chances for widespread showers and storms from tonight through Wednesday.

- Severe weather potential remains shrouded in forecast uncertainty here in Eastern Kentucky, but a stronger line of storms is expected to approach the I-75 corridor early on Tuesday morning.

- Additional thunderstorms are possible later on Tuesday and again on Wednesday, and these will bring highly beneficial rainfall to the region.

- Once a frontal boundary finally clears the area late next week, cooler than normal temperatures are favored.

UPDATE

Issued at 725 AM EDT MON APR 27 2026

No significant changes were made to the forecast with mainly just the inclusion of the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones.

LONG TERM

(Tuesday night through Sunday) Issued at 300 AM EDT MON APR 27 2026

There will be another chance for strong to severe thunderstorms on Tuesday evening as a shortwave ejects out of the Ozarks and into the Lower Ohio/Tennesseee River Valleys. Ahead of this feature, moisture will be pooling on the south side of the stalled boundary. This results in a crescent-shaped corridor of dewpoints above 60 degrees stretching from the Lake Cumberland region through the I-75 corridor and into the Bluegrass region along I-64. In the mean LREF data, this corresponds with a narrow tongue of 1000-1500 J/kg of MUCAPE around 8PM Tuesday evening. The dynamic lift provided by the approaching negatively-tilted trough should combine with strong midlevel flow to provide enough lift and bulk shear for organized storm clusters. These clusters will want to ride the instability gradient into our CWA from the west. The greatest CAPE values are generally resolved in southwestern portions of our CWA, near Lake Cumberland, and SPC has placed Wayne, Pulaski, McCreary, and Whitley counties in a Slight (Level 2/5) Risk for severe storms on Tuesday. The rest of the forecast area is denoted in a Marginal (Level 1/5) Risk, largely due to the conditional nature of the afternoon risk and the potential for multiple failure modes. One of the factors that could result in a forecast bust is convective cloud debris blowing off stronger convection to our southwest in the Tennessee Valley. Machine learning guidance has been more aggressive with the severe probabilities to our southwest, and the activity there could rob us of the necessary instability for stronger storms. The core of the nocturnal low-level jet with this system is also relegated to the Tennessee Valley. This reduces the amount of low-level shear available to storms, so damaging wind gusts and hail would be the primary hazard types with any sustained storm clusters on Tuesday evening. It is also plausible that that upstream activity once again weakens as it moves into our CWA, and Tuesday evening convection will remain a low-confidence forecast until the exact evolution of the morning activity becomes clear. Any convection that occurs on Tuesday will cause the stalled boundary/effective boundary to creep towards the south, as will the ejection of Tuesday night's shortwave. The surface low associated with this disturbance will move through the Ohio River Valley on Wednesday morning and pull the boundary southeast into the CWA. Depending on what time FROPA occurs, one last round of showers/thunderstorms is possible in our CWA on Wednesday. The approaching front, the digging of a more robust trough aloft, and the area's positioning in the vicinity of the left exit region of a 300mb jet streak should provide enough lift for precipitation. Likewise, the strength of the midlevel flow should maintain the approximately 40 knots of effective bulk shear. The thermodynamic environment is highly uncertain though. While Tuesday night's cloud cover should result in mild lows around 60 degrees, clouds should be rather prevalent on Wednesday as well. Forecast highs trend notably cooler (upper 60s to lower 70s) on Wednesday compared to previous days, which keeps the mean LREF instability values in the 500-1000 range. A HSLC (high shear, low cape) type set-up cannot be ruled out with any frontally forced convection, but the available ML/AI/Analog guidance only resolves low-end, marginal-type severe probabilities across the southeastern third of the forecast area on Wednesday. At the very least, this third round of activity will cement the notion that some highly beneficial rainfall is in store for Eastern Kentucky this week. A wetting rain at the very least is highly probable for Tuesday night through Wednesday per the 12Z/26th LREF(0.25 inches or more of precipitation) is almost certain, with 85-95% probabilities resolved area-wide for this threshold. Probabilities for 0.50 inches of rain or more is in the 50-65% range also per the 12Z/26th to per the LREF. Rain from that time period as well as any prior will prove highly beneficial to the ongoing drought across Kentucky, and it should lessen lingering fire weather concerns.

Deeper mid to upper level troughing digs into the Ohio River Valley headed into the weekend. Strengthening WNW flow aloft will work to advect a cool, continental airmass into the forecast area, and the aforementioned, stubborn frontal boundary is poised to finally shift further from the CWA by late Wednesday night. Precipitation chances and sky cover tapers off as drier air filters in throughout the column, giving way to highs in the 60s and lows in the 30s and 40s. These readings are below climatological norms for Eastern Kentucky. To end April into early May, reinforcing shots of colder air arrive in the region as shortwave disturbances rotate around the base of the broader trough. The odds for precipitation with these disturbances appear minimal perhaps best Friday into Friday night, and there continues to be a trend toward a cutoff upper level low developing in the NE CONUS for the upcoming weekend. Such a pattern favors below normal temperatures in Eastern Kentucky for the first days of May. The CPC extended-range hazard outlook is centered around these colder temperatures due to their potential to cause a frost, and their 6-10 day temperature outlook now highlights a 60- 70% chance of below normal temperatures across the greater Ohio River Valley. Those with interests sensitive to frost (such as agricultural crop producers or recreational gardeners) are accordingly encouraged to continue to monitor for updates as the calendar turns to May. As of the time of writing, the coldest nights look to be in the May 2nd to May 4th time frame. The pattern of a sfc high building into the region on Saturday night to early Sunday the 3rd would be the most favorable for a threat of frost.

AVIATION

(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 750 AM EDT MON APR 27 2026

VFR conditions will prevail through at least the first half of the TAF period. Expect mainly high clouds at times until late tonight when some showers and storms start to work into the area from the west with MVFR conditions possible - worsening towards dawn, Tuesday. Winds will generally be light and variable at less than 10 kts through mid morning before becoming southerly at 5 to 10 kts after 15Z picking up to between 8 and 12 kts with gusts up to 20 kts into the night.

JKL WATCHES/WARNINGS/ADVISORIES

None.