161 FXUS64 KJAN 291507 AFDJAN Area Forecast Discussion National Weather Service Jackson MS 1007 AM CDT Mon Jun 29 2026 ...New MESOSCALE UPDATE... .KEY MESSAGES... - Dangerous heat stress this week, with afternoon heat index values generally between 105F-110F. && .MESOSCALE UPDATE... Issued at 1007 AM CDT Mon Jun 29 2026 Weather conditions will remain quiet across our CWA this morning as near term guidance shows high pressure aloft sliding and positioning itself east of the region. Dangerous heat stress will prevail across our entire forecast area this afternoon as highs climb into the mid to upper 90s. These temperatures, combined with dewpoints in the 70s, will yield heat index values to exceed above 105 degrees. No changes have been made to the heat graphic and an areawide "Elevated" risk for dangerous heat will continue to be advertised. Likewise, a Heat Advisory remains in effect for our entire area, including portions of southeast AR and northeast LA, until 9 pm Tuesday. /CR/ && .DISCUSSION... Issued at 234 AM CDT Mon Jun 29 2026 Today through Sunday...Not a lot has changed in the overall forecast picture for the next week, with the primary concern being that of dangerous heat stress across the CWA. High pressure aloft will slide and position itself east of the region during the period. While today will again remain rain free, chances for mainly afternoon and evening showers and storms will begin increasing across the forecast area Tuesday, with decent chances remaining in the forecast into the Independence Day weekend. This is due to several disturbances caught up in easterly flow aloft, on the southern periphery of the aforementioned high aloft, moving east to west through the forecast area. As far as the heat stress is concerned, highs will climb into the mid and upper 90s today through Wednesday, with mid 90s forecast areawide Thursday into the weekend. These temperatures, coupled with dew points in the 70s, will yield afternoon heat index values above the century mark throughout the forecast period. At the moment, heat indices look their highest today through Wednesday, as values peak up around 110F. As a result, a "Heat Advisory" is in effect through Tuesday, and will likely be extended into Wednesday. After Tuesday, increased rain chances across the forecast area each afternoon could have an affect on just exactly how high heat index readings can climb. Despite this, confidence in indices between 105F-110F remains high enough that we'll continue to advertise an "Elevated Threat" for dangerous heat stress conditions in the HWO through the week. We will also continue to evaluate on a daily basis the extension of the "Heat Advisory" further into the week. /19/ && .AVIATION... (12Z TAFS) Issued at 622 AM CDT Mon Jun 29 2026 Patchy MVFR fog or stratus ceilings are possible mainly across south MS and central LA around daybreak this morning and again around daybreak Tuesday morning. Otherwise, VFR conditions will prevail through the TAF period with light wind. /DL/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 95 75 95 75 / 0 0 10 20 Meridian 98 76 98 76 / 0 0 10 10 Vicksburg 94 75 95 76 / 0 0 0 10 Hattiesburg 97 75 97 76 / 0 0 30 40 Natchez 96 75 97 76 / 0 0 10 20 Greenville 94 75 96 76 / 0 0 0 0 Greenwood 96 74 99 76 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Heat Advisory until 9 PM CDT Tuesday for MSZ018-019-025-034-035- 040>042-047-048-053>055-059>066-072>074. Heat Advisory until 9 PM CDT Tuesday for MSZ026>033-036>039- 043>046-049>052-056>058. LA...Heat Advisory until 9 PM CDT Tuesday for LAZ007>009-015-016- 023>026. AR...Heat Advisory until 9 PM CDT Tuesday for ARZ074-075. && $$ CR/19/DL