textproduct: Jackson

KEY MESSAGES

- A cold front is expected to bring isolated to scattered showers and perhaps a few thunderstorms to the region today. An isolated strong storm cannot be ruled out nearer to the WV border.

- Patchy frost is possible late Thursday night into early Friday morning in sheltered rural valleys and hollows, away from mainstem rivers.

- Additional shower and thunderstorm chances arrive to start the weekend followed by a pattern shift that favors temperatures 10 to 15 degrees above normal.

LONG TERM

(Friday through Wednesday) Issued at 542 PM EDT Wed May 13 2026

The surface high pressure system responsible for Thursday night's efficient radiational cooling is expected to shift east throughout the day on Friday. Diurnal mixing should allow any lingering valley fog to burn off by mid morning, and mostly clear skies will allow for ample solar insolation through Friday afternoon. Expect highs to recover to the mid to upper 70s as light winds veer towards a more southerly orientation. It will feel quite pleasant outside, with mixed dewpoints in the upper 30s/lower 40s during peak heating hours. While the resultant dewpoint depressions correspond with near- critical relative humidity thresholds, the light pressure gradient will keep wind speeds light and any fire weather concerns at bay.

The aforementioned high pressure and its parent ridging features aloft look to strengthen over the SE CONUS this weekend. A series of shortwave disturbances ejecting around the northwestern periphery of this ridge and into the Greater Ohio River Valley will progressively pull a warm front through our forecast area from Friday night into Saturday. Chance PoPs spread northeast across the forecast area as overrunning moisture arrives after midnight on Saturday morning. This initial convection is not likely to be very deep or very strong, and depending on the arrival time of the associated cloud cover, it may be elevated over a nocturnal radiation inversion. Recent forecast guidance suite has trended a little quicker with the arrival of the first impulse aloft, and the resultant timing uncertainty currently precludes the explicit mention of ridge-valley temperature splits in Friday night forecast grids. Generally speaking, increasing cloud cover and strengthening wind fields should relegate overnight lows to seasonably mild readings in the mid to upper 50s. However, a post-midnight arrival would allow for enough time for valleys to decouple after sunset, and this has been realized in recent analogous set ups.

The persistence and continued strengthening of southwesterly low level flow behind Friday night's boundary will pump a warm, moist airmass into the area on Saturday morning. The front is likely to stall out by midday, but a second, reinforcing disturbances arrives later that afternoon and triggers additional storms. Saturday does not look look like a total washout though, as this second round of convection will likely be isolated to scattered in nature. Showers and storms will have more instability to work with on Saturday than they did on Friday night, but there are several limiting factors present. The LREF depicts a south-north gradient of 500-1000 J/kg of CAPE, but with increasing CIN the closer one gets to the strengthening southeastern ridge. Shower/storm coverage will be greater closer to the boundary, which is progged to be somewhere to the north of the Mountain Parkway corridor on Saturday afternoon. This overlaps with the greatest instability, but the weak nature of the dynamics aloft does not favor sufficient bulk shear for organized updrafts. Thus, Saturday's convection appears pulsy, with a chance for small hail, gusty winds, and frequent lightning in the strongest cells. Widespread severe weather is not currently anticipated, although mesoscale trends and radar data will be monitored closely.

Once the boundary lifts well to the north of the forecast on Saturday night, the area's sensible weather will be driven primarily by the further-strengthening ridge. The flow aloft will back further and further towards the southwest as troughing digs deeper into the Great Plains early next week. Such a synoptic pattern favors a noticeable warming trend, and subsidence under the ridge favors mostly clear skies and efficient diurnal warming processes on both Sunday and Monday. The deterministic baseline NBM data has been running too hot in this time frame, bringing temperatures into the 90s on Sunday. Taking a look at the broader probabilistic forecast envelope, temperatures are more likely to reach the 90s on Monday than on Sunday. Midlevel heights reach their maxima on Monday, and there is greater probabilistic support for highs in the lower half of the 90s by then. In coordination with neighboring WFOs and WPC, highs were capped in the upper 80s on Sunday and below 95 on Monday. Ridge-valley splits and river valley fog will be possible after dark on both days.

While the flow aloft favors efficient warm air advection around the ridge on Sunday and Monday, the more robust moisture return will likely hold off until Tuesday. This will limit the magnitude of any associated heat risk concerns, but record highs at the KJKL and KLOZ climate sites are still in jeopardy. The timing of this early-season heat coincidentally aligns with the 2026 National Integrated Heat Health Information System's Heat Safety Week campaign. Interests are accordingly encouraged to monitor official NWS social media channels to learn more about heat-related impacts and heat safety tips next week. Deeper troughing emerges in the Plains on Tuesday and orients the flow in manner that gives our area better access to Gulf moisture. As the trough and its attending surface low eject into the Upper Midwest on Tuesday, a cold front approaches Kentucky. That boundary is likely to stall out to the west of our CWA, but the return flow out ahead of it will yield widespread dewpoints in the 60s. The greater humidity in the atmospheric column will correspond with increased cloud cover, so temperatures readings on the thermometer will likely be a couple of degrees cooler than they were on Monday. Highs in the upper 80s will combine with the aforementioned dewpoints to produce plenty of instability for isolated to scattered open warm sector storms on Tuesday afternoon and evening. PoPs increase overnight into Wednesday as the front sags southeast, and that frontal passage should facilitate a return to more seasonably appropriate temperatures by midweek.

AVIATION

(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 145 PM EDT WED MAY 13 2026

All sites are starting off the period VFR and most will remain VFR through the TAF period. A cold front noted to our northwest is slated to push across the area this afternoon and evening. This could help to develop some showers and even thunderstorms this afternoon and evening. However, the convective trends have been on the decline in some of the guidance. Either way maintained some Prob30 for lower vis and cig potential at JKL and SJS TAFs given this potential, but on the lower confidence side. The best chances of seeing precipitation is more in the far southeastern portions of eastern Kentucky. The bigger impact will be the increasing winds becoming more westerly this afternoon at 10-15 knots with gusts in the 15-25 mph range. These winds will become more northwesterly through the later afternoon and evening and then diminish generally after 00Z.

JKL WATCHES/WARNINGS/ADVISORIES

None.