textproduct: Jackson

KEY MESSAGES

- Dangerous heat stress conditions are expected across at least portions of the forecast area through the end of this week.

- Isolated severe storms capable of damaging wind gusts are possible across portions of the area today and tomorrow.

MESOSCALE UPDATE

Issued at 942 AM CDT Wed Aug 19 2026

Forecast has been updated through the daytime tomorrow based on latest guidance. Changes primarily to updated POPs and weather through this evening, with an adjustment to expand the Marginal Risk for severe storms today. Overall forecast reasoning remains on track. /NF/

DISCUSSION

Issued at 448 AM CDT Wed Aug 19 2026

Through tonight: Heat and humidity will remain the main concern in the short term although there will be the potential for isolated strong to severe storms across the northeast half of the CWA this afternoon. Early morning satellite imagery/RAP analysis showed our CWA on the eastern periphery of a weakened 592dam ridge that will continue to provide northwest flow aloft through tonight. At the surface a nearly diffuse stalled frontal boundary was noted just north of our CWA. Similar to Tuesday, convection is expected to initiate along this stalled boundary spread to the southeast across the northeast half of our CWA into this evening. Latest guidance suggest the environment will support isolated strong to severe storms capable of damaging wind gusts. This may bring some relief to the heat today in the areas that receive rain but otherwise, temperatures in the upper 90s to lower 100s will combine with relatively high humidity to result in heat indices just above 110F along the Mississippi river and southern zones with 105-110F expected again elsewhere. Thus, an Extreme Heat Warning has been issued for the area along the Mississippi river while the Heat Advisory remains in effect for the remainder of the CWA today. The convection will taper off this evening but the warm and humid conditions will continue tonight. /22/

Thursday through next Wednesday...

What's a three letter word that starts with 'h' and ends with 't'? Here's a quick little hint, it rhymes with dot. If you guessed the word 'hot' then you would be correct because that is what we're going to be dealing with for the entire extended forecast period. Hot and humid conditions will prevail across our entire forecast area for Thursday. Similar to the last few previous days, afternoon highs across our CWA will peak into the upper 90s to the low 100s. This combined with mostly sunny skies combined with increased humidity will cause heat index reading values to peak in the 105-110 degree range. Several areas west of I-55 could see heat indices exceed 110 degrees. A Heat Advisory will likely be needed for the entire area for Thursday and again on Friday. Late afternoon rain and the frontal boundary may keep max values just below Extreme Heat Warning criteria. Will continue to closely monitor heat trends for any potential upgrades.

Regarding the rain chances, guidance shows a weak sfc trough that will develop eastward across AR into northern MS. This combined with increased deeper moisture, increased convergence from frontal zone sagging southward will allow for better rain coverage over portions of east MS and north MS over the next several days particularly during the late afternoon/early evening hours. Storm coverage will be scattered as we go through the late week and into the weekend. Given the increased heat and humidity, scattered strong to marginally severe storms cannot be ruled out.

Steepening northwest flow aloft, associated with a building ridge over the western CONUS, will allow for a couple of disturbances to bring rain chances into our forecast area through early next week. Will also nudge temperatures slightly cooler, but still August-level heat. A slight chance for showers and storms (PoP around 20%) will cannot be ruled out across much of our area by Wednesday. /CR/

AVIATION

(12Z TAFS) Issued at 632 AM CDT Wed Aug 19 2026

Isolated to scattered TSRA are psbl this aftn over the east and se TAF sites and may bring lower flying conditions. Otherwise, VFR conditions will prevail areawide through the end of the TAF period. /22/

PRELIMINARY POINT TEMPS/POPS

Jackson 100 77 99 76 / 20 20 10 10 Meridian 100 75 99 74 / 20 10 30 20 Vicksburg 99 77 99 76 / 10 0 0 10 Hattiesburg 99 76 99 75 / 40 10 10 20 Natchez 99 76 100 76 / 0 0 0 0 Greenville 102 79 101 77 / 20 0 20 20 Greenwood 100 77 99 74 / 20 0 30 30

JAN WATCHES/WARNINGS/ADVISORIES

MS...Heat Advisory until 9 PM CDT this evening for MSZ026>033-037>039- 044>046-049>052-054>058-062>066-072>074.

Extreme Heat Warning until 9 PM CDT this evening for MSZ018-019- 025-034>036-040>043-047-048-053-059>061.

LA...Heat Advisory until 9 PM CDT this evening for LAZ007-015-023.

Extreme Heat Warning until 9 PM CDT this evening for LAZ008-009- 016-024>026.

AR...Heat Advisory until 9 PM CDT this evening for ARZ074.

Extreme Heat Warning until 9 PM CDT this evening for ARZ075.