textproduct: Jackson

KEY MESSAGES

- A warming trend will last for the next few days, with climbing humidity lasting longer.

- A cold front moving into the area will bring a potential for rain from Friday into next week.

UPDATE

Issued at 145 AM EDT TUE SEP 29 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 SAFs and zones.

UPDATE Issued at 953 PM EDT MON SEP 28 2026

Made minor adjustments to temperatures in the very near term based on latest obs. There are no substantive changes to tonight's forecast as a whole.

UPDATE Issued at 804 PM EDT MON SEP 28 2026

In light of minimum afternoon dew points, have raised tonight's forecast minimum temperatures in southwestern valleys from where they had been.

LONG TERM

(Wednesday through Monday) Issued at 446 PM EDT MON SEP 28 2026

The long-term period opens Wednesday morning with upper level ridging in place over the Southeast CONUS, mirrored at the surface by high pressure offset to the east over the Western Atlantic. This will be maintaining a mild southerly flow across the Ohio Valley. Looking upstream, a mean 500 hPa trough will be in place over western Canada while a closed ~568 dam low spins over the Lower Colorado River Valley. The trough will be supporting an ~991 mb surface low over the Upper Mackenzie River Valley with a cold front extending southward into the Northern High Plains and then westward across the Columbia River Basin. Another ~1000 mb low is noted over the Southern Rockies ahead of the aforementioned closed low.

For the first few days of the long-term, the upper level ridging will drift eastward to off the Southeast Coast. This will keep southerly flow and an unseasonably warm air mass (mean 850 hPa temperatures ~16-18C, as per the LREF) and mostly dry conditions in place over eastern Kentucky through Friday. In the meantime, the closed low over the Desert Southwest will open up and be captured the eastward-propagating northern-stream trough. As that trough shifts eastward, it will suppress the 500 hPa ridging over the Ohio Valley, transitioning the flow aloft to quasi-zonal/weakly troughed. The cold front associated with the trough will move into the Ohio Valley but then struggle to make further southeastward progress Friday night-Saturday night as energy ejects out of the opening low and rides along the boundary. Meanwhile, PWATs could exceed the 90th percentile if the NAEFS/ECMWF mean solution materializes, amidst deep moisture advection from the Gulf of America. If ingredients come together ideally, a decent soaking rainfall is possible across portions of eastern Kentucky or adjacent regions this weekend, but forecaster confidence is low. From a more sensible standpoint, this pattern will bring back the return of a summer-like feel for the remainder of the work week with dew points recovering back through the 50s and into the 60s while afternoon temperatures peak in the low to mid 80s from Wednesday through Friday. Some of the hotter portions of the Cumberland could flirt with the upper 80s. Rain chances will then knock back the high temperatures for Saturday but it will still be quite humid with the threat of rainfall and possibly a few rumbles of thunder.

Change will be around the corner to close out the first weekend of October. Within the broad upper level troughing, a quick-moving shortwave trough transiting the 49th Parallel (US-Canada border) over the weekend will phase with northern stream energy diving southeast from the Yukon. This will bring height falls to the Ohio Valley early next week while slinging an associated cold front across the Coalfields Sunday into Monday. Behind that front, LREF mean 850 hPa temperatures drop to ~9-11C with much drier PWATs (0.6 to 0.8 inches) by late Monday. Rain chances taper off behind the first cold front on Sunday and appear minimal with this second boundary. Instead, the more noticeable effect will be a decline in temperatures to more seasonable levels for Monday with highs returning to the mid 60s to lower 70s and cool nighttime lows in the 40s and 50s.

AVIATION

(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 210 AM EDT TUE SEP 29 2026

Valley fog will last into morning. Confidence is not high, but in light of some fog already showing up in the satellite images, have included a TEMPO group for IFR or worse for several hours at many sites around dawn. Outside of fog, VFR conditions will hold through the period along with light winds.

JKL WATCHES/WARNINGS/ADVISORIES

None.