textproduct: Jackson

KEY MESSAGES

- Heat headlines remain in effect through 9 PM EDT tonight. Highs near 90 degrees and muggy conditions will produce peak heat index values in the 90s to over 100 degrees before dropping off tonight.

- Mainly dry, warm, and humid conditions will favor fireworks displays this evening, outside of an isolated shower or storm. River valley fog develops overnight.

- 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.

LONG TERM

(Monday through Saturday) Issued at 424 PM EDT SAT JUL 4 2026

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 Sunday afternoon) ISSUED AT 151 PM EDT SAT JUL 4 2026

Patchy VFR cloud cover, mainly convective debris clouds, is passing over the area at TAF issuance. Through the afternoon, current expectation is a limited cumulus field at most locations, through ongoing convection over VA/WV could impact far eastern Kentucky, mainly east of US-23, this evening. This warranted a PROB30 group at SJS. Elsewhere, while an isolated shower or thunder is possible, confidence in impacts were too low to mention at this time. A more widespread shower and thunderstorm threat will come on Sunday with the approach of a shortwave trough.

JKL WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 9 PM EDT this evening for KYZ044-050>052- 058>060-068-069-079-080-083>085.

Extreme Heat Warning until 9 PM EDT this evening for KYZ086>088- 104-106>120.