textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1027 PM CDT Mon Aug 17 2026

- Dangerous heat continues with afternoon heat indices commonly reaching 110115F through the week. Warm overnight temperatures will offer limited relief.

- Only isolated to scattered afternoon storms are expected the next couple days. Coverage should be somewhat greater toward the Mississippi coast and eastern portions of the forecast area.

SHORT TERM

(Now through Friday) Issued at 1027 PM CDT Mon Aug 17 2026

We are pretty close to where we should be for this time of year. Hot, humid and oppressive sums it up for mid August. The heating is quite intense and storms that do develop during this heat will not have many others around to compete with for that energy which means any particular storm can go rogue causing damaging winds and all other attributes of severe thunderstorms. This is typical for our summers though. There is always a silver lining somewhere, and with any of these storms, there will be some cooling shade and rain. The big picture is still playing out like it should as the large high over the EastPac is now starting to show some leveraging into the SW CONUS. The H3 level will show how these synoptic systems play out the best. As the large high gets into place over the SW, this will amplify the polar jet along the west coast causing a deep upper trough to set up down stream to the east sending the large upper low, taking up a very large amount of Canadian real estate, toward the southeast. The west side of this trough will begin to tap much stronger winds on its west side as the large high squeezes the upper trough. The much stronger winds on the west side of the upper trough will cause it to start digging into the central part of the country by late week, and by Friday we should see a very strong upper trough moving toward the southern CONUS. This synoptic weakness will also help more storms get going as well. We will see the scattered version of storms until the end of this week when the attending frontal system starts to help plenty of storms fire up along and ahead of it as it moves toward the area by Fri.

LONG TERM

(Friday night through Monday) Issued at 1027 PM CDT Mon Aug 17 2026

As we move into the long term portion of the forecast, the global models agree on the large scale pattern with ridging centered near the Four Corners area, and near Bermuda, with troughing over the Great Lakes and Appalachians, extending southward into Florida. Some of the differences we had seen in last night's solutions have for the most part resolved themselves. The upper weakness we had been seeing depicted in the eastern Gulf now is depicted by both families of medium range modeling to be picked up by the northern stream trough and carried northeastward along the Atlantic Coast. That's similar to the ECMWF based solutions we looked at last night.

This solution with northwesterly upper flow will bring a surge of drier air into the area, with precipitable water values near 2 inches on Friday down to around 1.5 inches Saturday afternoon. That's pretty close to the 25th percentile climatologically. As we saw last week, that doesn't preclude convective development, but is likely to keep any development rather isolated and limited to max heating hours. That drying trend looks to continue through Sunday before moisture starts returning on Monday. I'd expect we'll probably see a bit of a downward trend in precipitation chances for Saturday in the next day or so, but don't anticipate any completely dry days. And as always with northwest mid-level flow, we can't rule out convective complexes approaching from that direction.

Don't really see high temperatures changing much through the weekend, with highs in the mid and upper 90s every day, and isolated locations perhaps touching 100. We may have a couple days of lower humidities and slightly cooler low temperatures over the weekend, but not counting on that quite yet.

AVIATION

(06Z TAFS) Issued at 1027 PM CDT Mon Aug 17 2026

Outside TSRA developing late in the day, VFR will be the rule for this taf cycle. Those sites with the highest chances of getting sh/ts will be shown with timing.

MARINE

Issued at 1027 PM CDT Mon Aug 17 2026

Surface high pressure centered over the central Gulf will maintain a generally weak pressure gradient through much of the period. A predominantly westerly flow will continue, with higher winds at 10 to 15 knots during the night and morning hours then generally lighter wind speeds during the daylight hours. Isolated thunderstorms will remain possible with winds and waves higher in and near this activity, particularly during the overnight and early morning hours.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Heat Advisory from 11 AM to 8 PM CDT Tuesday for LAZ034>037-039- 046>048-056-070-071-090-091-093>097.

Extreme Heat Warning from 11 AM to 8 PM CDT Tuesday for LAZ057- 058-064-076>087-089-092-098>100.

GM...None. MS...Heat Advisory from 11 AM to 8 PM CDT Tuesday for MSZ068>071-077.

Extreme Heat Warning from 11 AM to 8 PM CDT Tuesday for MSZ083>088.

GM...None.