textproduct: Jackson

KEY MESSAGES

- An Elevated threat for dangerous heat stress conditions is expected through this weekend and into next week. Significant heat is possible in some areas.

- Rain chances are minimal through most of the forecast period.

DISCUSSION

Issued at 149 PM CDT Wed Aug 12 2026

The threat for dangerous heat stress conditions continues to be our greatest message by far. The subtropical ridge building, expanding, and intensifying overhead as we move into the weekend will be quite strong. 500 mb heights of 597 to 598 dam are just below records for mid August. Subsidence beneath the ridge and increased sunshine will continue to dry and bake the South into next week. As the ridge strengthens, some of the humidity will be eased, but actual air temperatures will begin to push or exceed 100 degrees. The combination of heat and humidity will ensure most days see peak heat index values in the 105-110 degree range through the weekend.

Local temperature climatology studies suggest that a range of 850mb temperatures of 21-24C would support high temperatures pretty reasonably in the 97 to 103 degree range. Official forecast values are on the upper end of this range, so would conservatively say that at least parts of our forecast area will hit the 100 degree mark during the next 7 days, and a few locations may reach 103, or hot enough to set record highs. Deeper mixing would push the dew points slightly lower, but would also feel pretty confident in the 105+ heat index values, especially as recent guidance has come in with slightly higher RH forecasts. Will continue to monitor for potential expansion and increase of messaging to "Significant" risk of dangerous heat (110+ heat index or 105+ air temperature) as we move into late week and the weekend. An areawide Heat Advisory is in effect, and expect additional Advisories or Excessive Heat Warnings to be issued over the coming days.

In terms of rain chances, they are mostly non-existent until early next week. At that time, there is a signal for deeper moisture in the westerlies north of the high center to circulate around the high and potentially increase convective rainfall chances over eastern portions of the forecast area. Rain chances could be further increased by an approaching frontal boundary, but any relief from the heat that could result is uncertain at this time. /NF/EC/

AVIATION

(00Z TAFS) Issued at 729 PM CDT Wed Aug 12 2026

VFR conditions wl prevail through the TAF period. /22/

PRELIMINARY POINT TEMPS/POPS

Jackson 77 98 76 99 / 0 0 0 0 Meridian 77 98 77 99 / 0 0 0 0 Vicksburg 77 97 75 97 / 0 0 0 0 Hattiesburg 77 98 76 100 / 0 0 0 0 Natchez 76 98 73 99 / 0 0 0 0 Greenville 79 100 78 100 / 0 0 0 0 Greenwood 78 97 78 99 / 0 0 0 0

JAN WATCHES/WARNINGS/ADVISORIES

MS...Heat Advisory until 7 PM CDT Friday for MSZ018-019-025>066- 072>074.

LA...Heat Advisory until 7 PM CDT Friday for LAZ007>009-015-016- 023>026.

AR...Heat Advisory until 7 PM CDT Friday for ARZ074-075.