textproduct: Jackson

KEY MESSAGES

- Dangerous levels of heat stress will continue today with less oppressive conditions expected Sunday.

DISCUSSION

Issued at 351 AM CDT Sat Jul 4 2026

Through tonight: the large mid level high that has been over the region the past several days has shifted east of our region leaving a flatter ridge early this morning. This flat ridge will gradually deepen into a weak upper level trough aloft through tonight in response to a large high anchoring over the southern Plains. The 00Z Sat JAN sounding showed a PWAT back up to two inches. This moist airmass and the lower heights today will lead to a greater coverage of isolated to scattered afternoon into early evening showers and thunderstorms. Although the greater coverage of convection today and potentially earlier development will result in lower peak heat index values. However, the combination of temperatures in the 90s and high humidity will result in peak heat index values in excess of 105F over most of the CWA again. A Heat Advisory will remain in effect for the whole CWA today. The convection today will see a distinct diurnal trend but the presence of the deepening upper level trough may help prolong convection tonight. /22/

Sunday through next Saturday...

The subtropical ridge will start to weaken slightly across the southeast CONUS heading into Sunday. This combined with southerly moisture return flow from the Gulf will help support greater coverage of scattered showers and storms much of the area with rain chances around 25-50% especially during late afternoon/early evening timeframe. Areas along and south of I-20 will have better chances (50-76%) of scattered convective rainfall coverage. A few strong storms with wind gusts between 40-50 mph cannot be ruled out. Because of the showers and storms forecasted for Sunday, most of our forecast area could see heat index values drop below the 105 degrees threshold, so will hold off on extended the heat advisory further. Showers will persist heading into the new work week as the hot and humid airmass remains unchanged. Long term guidance is starting to show the sfc high restrengthening across the area by the mid week. This will allow for heat peak heat index values to climb back into potential heat advisory criteria. Heat graphics and advisories may eventually be needed as we get closer to the late week. Heat trends will continue to be monitored on a daily basis. Much of our area will see decent rain chances (15-40%) by next week Friday. Scattered showers and storms cannot be ruled out across much of our area heading into the weekend. /CR/

AVIATION

(12Z TAFS) Issued at 619 AM CDT Sat Jul 4 2026

IFR/LIFR vsby wl be psbl in east MS until after 14Z. After 14Z VFR conditions are expected to prevail until this aftn when isolated SHRA/TSRA wl be possible in the west and may come in vcty of cntrl MS TAF sites. The potential for TSRA wl end by 02Z Sun. VFR conditions wl continue until after 08Z when MVFR vsbys wl begin developing at most TAF sites. /22/

PRELIMINARY POINT TEMPS/POPS

Jackson 93 75 91 74 / 40 20 50 10 Meridian 95 75 93 74 / 20 20 60 20 Vicksburg 93 75 91 75 / 30 10 60 10 Hattiesburg 94 75 93 74 / 20 10 70 20 Natchez 94 75 91 74 / 40 30 70 10 Greenville 94 75 92 75 / 30 20 40 30 Greenwood 95 75 93 74 / 40 30 50 20

JAN WATCHES/WARNINGS/ADVISORIES

MS...Heat Advisory until 8 PM CDT this evening for MSZ018-019-025>066- 072>074.

LA...Heat Advisory until 8 PM CDT this evening for LAZ007>009-015-016- 023>026.

AR...Heat Advisory until 8 PM CDT this evening for ARZ074-075.