textproduct: Jackson

KEY MESSAGES

- Dangerous heat stress this week, with afternoon heat index values generally between 105F-110F.

- Dangerously hot conditions tomorrow with prolonged heat stress possible. Heat indices 110+ possible.

- Marginal Risk for isolated severe storms across the area tomorrow.

DISCUSSION

Issued at 121 PM CDT Tue Jun 30 2026

Through mid next week...

Our area remains largely under the influence of a midlevel high over the southeast CONUS this week with heat a primary concern in the short term, and afternoon and evening convection each day. Temperatures in the mid 90s along with mid 70s dewpoints will support heat indices in the 105-110 range both today and tomorrow and a heat advisory continues areawide through late tomorrow.

With the center of the high situated over the area today, drier air will limit convection for much of the area. There may be a little greater moisture along with around 20kts of flow in the southeast today. This may be just enough to support isolated convection with an isolated wind gust, mainly this evening, and thus a "marginal" risk has been highlighted. The caveat is the fact storms will be running into drier air as they push into our area, and it is possible that they stay just east of our area.

The combination of heat and humidity looks to be even greater tomorrow, particularly along and west of I-55 where convection is overall less likely, and/or convection arrives later. There is likely a 5-6 hour window where heat warning criteria 110+ will be met. An extreme heat warning and corresponding update of "significant" to this area in the graphic, have been issued.

The rest of the week, the midlevel high propagates northeastward, which introduces easterly flow and slightly lower heights. This weakness along with ample moisture should be enough to support westward propagating convection. There will be a chance daily, however tomorrow, with slightly increased flow, there looks to be better chance for organization, though this looks marginal and loosely organized in most CAMs at the moment. An areawide marginal has been added in the updated HWO graphics.

By the weekend, an upper low near the Canadian border will help to flatten and break down the ridge. With this, rain and storm chances should increase with greater coverage this weekend into early next week. All the while, heat stress could continue with temperatures in the low 90s and dewpoints maintaining in the low 70s. Therefore, it is reasonable to assume depending on certain environmental parameters that severe could be possible and daily monitoring will be needed. This hot and humid regime looks to persist through the rest of the period. /SAS/

AVIATION

(18Z TAFS) Issued at 1229 PM CDT Tue Jun 30 2026

VFR conditions and light to calm winds are expected to prevail at the TAF sites through the period. There is a slight chance for showers or a thunderstorm near KHBG or KPIB near 00Z Wednesday, but the chance for impacts from thunder is too low to mention in the TAF at this time. /NF/

PRELIMINARY POINT TEMPS/POPS

Jackson 96 77 95 75 / 0 10 40 20 Meridian 98 77 96 75 / 10 10 20 10 Vicksburg 95 77 95 76 / 0 0 40 10 Hattiesburg 97 76 95 75 / 10 20 50 20 Natchez 97 77 95 75 / 0 0 60 10 Greenville 96 77 96 77 / 0 0 20 10 Greenwood 99 77 99 76 / 0 0 30 10

JAN WATCHES/WARNINGS/ADVISORIES

MS...Heat Advisory until 9 PM CDT Wednesday for MSZ026>033-037>039- 044>046-050>052-056>058-060>066-072>074.

Heat Advisory until 10 AM CDT Wednesday for MSZ018-019-025- 034>036-040>043-047>049-053>055-059.

Extreme Heat Warning from 10 AM to 9 PM CDT Wednesday for MSZ018- 019-025-034>036-040>043-047>049-053>055-059.

LA...Heat Advisory until 9 PM CDT Wednesday for LAZ007-008-015-023- 024-026.

Heat Advisory until 10 AM CDT Wednesday for LAZ009-016-025.

Extreme Heat Warning from 10 AM to 9 PM CDT Wednesday for LAZ009- 016-025.

AR...Heat Advisory until 9 PM CDT Wednesday for ARZ074.

Heat Advisory until 10 AM CDT Wednesday for ARZ075.

Extreme Heat Warning from 10 AM to 9 PM CDT Wednesday for ARZ075.