textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 620 PM CDT Tue Aug 11 2026

- Isolated showers and thunderstorms will continue to be possible through tomorrow, but as the week continues storm coverage will decrease. Storm motion will be slow so with any thunderstorm brief heavy rain is possible, cloud to ground lightning, and higher wind gusts.

- Heat index readings will near advisory criteria this afternoon south and southwest of the tidal lakes but should remain just below 108 degrees. However, later this week the heat index values will range between 105 and 110 and heat advisories may be needed.

SHORT TERM

(Now through Thursday night) Issued at 120 PM CDT Tue Aug 11 2026

Today and Wednesday will be the most appreciable chances of rain this week and the chances aren't really high to begin with. Any convection that would form would be the seabreeze/diurnally driven storms but there is rather poor environment support with very little shear and poor lapse rates. Still plenty of CAPE and sufficient PW to go around so isolated ones are definitely on the table. Any storms that form could still have frequent lightning, gusty winds and locally heavy rainfall. As the upper level ridge builds even more that will really clamp down on convection chances, so the main concern will shift to heat. Decided to hold off on a heat advisory for tomorrow for now, as it's extremely borderline and isolated (mainly around the south side of Lake Pontchartrain). But as the week continues the chances of heat advisories will be increasing.

LONG TERM

(Friday through Monday night) Issued at 120 PM CDT Tue Aug 11 2026

A strong mid/upper-level ridge will remain the dominant feature through the weekend, with the upper high gradually shifting west from the Lower Mississippi Valley towards Texas and Oklahoma. Despite this westward shift, we will remain beneath the southeastern influence of the ridge with above-normal heights, warm temperatures aloft, and subsidence limiting convective development. With little synoptic forcing and somewhat suppressed deep-layer moisture, convection should be largely confined to isolated afternoon storms along sea/lake breeze and other mesoscale boundaries. Most locations should remain dry each day, with PoPs generally 20 percent or less.

Heat will remain the primary concern through the period as abundant insolation and limited convective cooling will allow highs to climb into the mid to upper 90s, with a few locations potentially approaching 100 degrees. Afternoon mixing may lower dewpoints somewhat more than indicated by the NBM, which could temper peak heat indices while also allowing temperatures to climb a bit higher. Even so, heat indices around 105 to 110 degrees will be possible, and heat headlines may eventually be needed for portions of the area. Little meaningful change in the overall hot and relatively dry pattern is expected through Monday as the ridge remains influential

AVIATION

(00Z TAFS) Issued at 620 PM CDT Tue Aug 11 2026

Isolated convection across the region has decreased this afternoon. Only one or two more showers remain across southeast Louisiana. After this afternoon, rain chances begin to decrease meaning outside of HUM no mention of convection for Wednesday. VFR and light southerly winds will continue through the cycle. (Frye)

MARINE

Issued at 120 PM CDT Tue Aug 11 2026

Strengthening high pressure will hold over much of the coastal waters this week, with winds remaining generally light 5 to 10 knots out of the southeast for a good chunk of the week. Chances of showers and storms will be increasingly isolated later this week, although they remain possible especially diurnally based ones or riding the edge of the high.

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...None. MS...None. GM...None.