textproduct: Jackson

KEY MESSAGES

- Scattered to numerous showers and storms return Sunday and Monday as a slow-moving cold front arrives. A few storms could produce isolated strong winds and localized flash flooding.

- The heat wave breaks next week, with daily highs returning to near-normal levels in the mid to upper 80s alongside daily chances for afternoon showers and thunderstorms.

UPDATE

Issued at 1210 AM EDT SUN JUL 5 2026

No big changes needed for this update. However, did make some minor PoP adjustments to account for radar trends, with convection developing along the higher terrain near the Virginia border. The latest CAMs have been varying in where convection develops and none of them are really doing well with the initiation this late morning hour. Given the lack of better forcing most convection will develop on higher terrain or outflows through the afternoon and evening.

UPDATE Issued at 730 AM EDT SUN JUL 5 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

(Monday night through Saturday) Issued at 345 AM EDT SUN JUL 5 2026

The main change to grids for the first part of the extended forecast this morning was to add in some slight terrain details each night on account of the diurnally clearing skies that are expected each night through Wednesday morning. Did also include some river valley fog toward dawn in the early morning grids. General troughing aloft still looks to keep things unsettled through at least the middle of the work week with seasonably warm temperatures and dewpoints still on the wet side of climatology.

The previous long term discussion follows:

The long-term period opens Monday with the prior week's heat wave just a memory. The 04/12Z model suite analysis beginning at 12Z Monday shows a split flow pattern over the Eastern Great Lakes with a positively-tilted trough extending southwestward into the Mid and Lower Mississippi Valley while a ridge axis extends northward to over northern Greenland. Meanwhile, an ~593 dam high will reside over the Upper Rio Grande Valley beneath a trough over Central Canada. At the lower levels, the pattern is subtle. A weak area of low pressure is likely to be in the vicinity of southern Indiana with a cold front extending southwest into the Ozarks.

Working through the upcoming work week, guidance is in fair agreement showing the upper-level trough propagating eastward with its axis crossing the CWA on Tuesday, causing the aforementioned cold front to drop through the forecast area. The notable exception is the ECMWF deterministic holding back a weak closed low over the Mid-Mississippi Valley which would inhibit the cold front's southward progression. Diurnally modulated deep convection is probable on both Monday into Tuesday with the frontal boundary nearing and dipping into the area. Greater uncertainty on overall convective coverage comes on Wednesday and depends on whether the front effectively dips south of the Commonwealth or gets hung up. In either case, the rain chances appear to increase again heading later in the week as the trough over Canada begins to dig southeastward and the Southwest US high shifts westward and then begins to amplify, pumping up a robust, positively tilted ridge axis from the Desert Southwest to southern Nunavut. At the surface, the front over us or to our south turns frontolytic as a new cold front settles southward toward the Ohio Valley.

In terms of heavy rainfall, a Marginal (level 1 of 4) ERO is in place through Monday night to highlight the threat of isolated flash flooding should storms become persistent over a given location ahead of the first cold front. A renewed low-end excessive rainfall threat may return late in the week as moisture returns ahead of the second boundary, but that is beyond the WPC ERO window at this point. Temperatures through the period will settle back into the mid to upper 80s for daily highs each afternoon while nighttime lows retreat into the 65 to 70F range for most locales. The typical valley fog is likely on any night with substantial clearing.

AVIATION

(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 155 PM EDT SUN JUL 5 2026

We are seeing some scattered cumulus develop this afternoon and these will remain around the 3.5 kft level in most cases. We are seeing some deeper convection develop along the higher terrain, but so far has been more limited than expected so far. Given this opted to push back the start time of the prob30 for thunderstorms another hour, but given the lack of convection so far this afternoon opted to not go tempo. Outside convection winds will remain light and variable generally below 5 knots.

JKL WATCHES/WARNINGS/ADVISORIES

None.