Area Forecast Discussion

KEY MESSAGES

- Dangerous levels of heat stress will continue during the late morning and afternoon hours today and Wednesday, mainly over the western half of the area. Heat danger will decrease later this week.

DISCUSSION

Issued at 221 AM CDT Tue Sep 15 2026

Through Wednesday: The heat wave continues as strong mid/upper ridging builds across the region. High temperatures will again approach the triple digits in many areas today and tomorrow, with high temp records in jeopardy at multiple local climate sites. One notable difference from recent days is a shift to easterly low level flow, gradually bringing a drier airmass into the area. This will yield lower heat indices across a portion of east central MS today and for most areas east of I-55 on Wednesday. A Heat Advisory remains in effect today for all other areas, and another may be needed tomorrow, though likely for a smaller area than today. With deep layer moisture becoming more limited to the southern and western portions of the area, that is the region where diurnal convection will be more likely today - south/west MS, northeast LA, and southeast AR. By tomorrow, the focus will be even more limited to south MS and central LA. A few of these storms could produce locally strong wind gusts.

Thursday through next Tuesday: A drier airmass will continue to shift into the area Thursday into Friday. This airmass will still support hot days, with temps still approaching the triple digits in the ArkLaMiss Delta through Saturday. But with dewpoints in the 60s, mixing down into the 50s at times, heat stress will significantly decrease through the end of the week. Morning temps will also dip into the 60s at times in many areas late this week. Deep layer moisture will begin to increase again this weekend into early next week, with returning chances for diurnal convection each day. /DL/

AVIATION

(06Z TAFS) Issued at 1220 AM CDT Tue Sep 15 2026

This is a low chance for brief patchy fog around daybreak. Then isolated to scattered SHRA/TS are possible mainly across south/west MS, northeast LA, and AR Tue afternoon, resulting in brief visby/ceiling reductions and gusty winds. Otherwise, VFR conditions will prevail through the TAF period with light wind. /DL/

PRELIMINARY POINT TEMPS/POPS

JAN WATCHES / WARNINGS / ADVISORIES

MS...Heat Advisory from 11 AM this morning to 7 PM CDT this evening for MSZ018-019-025>037-040>043-047>049-053>055-059>064-072.

LA...Heat Advisory from 11 AM this morning to 7 PM CDT this evening for LAZ007>009-015-016-023>026.

AR...Heat Advisory from 11 AM this morning to 7 PM CDT this evening for ARZ074-075.