textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 133 PM CDT Sat Jul 4 2026

- Very normal summer pattern with warm days and scattered daily showers and thunderstorms expected through the next several days. Chances of severe weather and heavy rain will be low, a few storms each day could become strong to severe with gusty winds and/or locally heavy rainfall.

- Waterspout activity will be possible over the coastal waters.

- Heat stress will be an impact throughout the forecast period with near heat advisory conditions each afternoon. The hottest timeframe looks to be latter half of next week.

SHORT TERM

(Now through Tuesday night) Issued at 133 PM CDT Sat Jul 4 2026

A broad weakening upper level ridge remains spread across the southern U.S. today, while surface ridging associated with the western Atlantic/Bermuda high extends across the Gulf. This pattern will keep the area hot and humid, but not completely capped off from convection today. The 12Z KLIX sounding showed PW near 1.9 inches, weak deep-layer flow/shear, and only modest mixed-layer instability at that time. However, temperatures have warmed into the lower/mid 90s with surface heating now helping reduce inhibition, especially near boundaries. Latest radar imagery supports this trend early this afternoon showing scattered thunderstorms ongoing near portions of the Louisiana coastline, mainly west of the mouth of the Mississippi. CWA convection inland remains limited so far, though a progressively developing cumulus field south of I-10 suggests gradual boundary layer destabilization is underway. Storms that do develop will be poorly organized, but slow/erratic storm motions, frequent lightning, brief heavy downpours, and gusty winds will be the main concerns. Localized nuisance flooding cannot be ruled out in urban or poor drainage spots, but the heavy rain threat should remain brief and isolated.

Heat remains a concern for the holiday weekend, especially where convection is delayed or absent. Highs should reach the lower to mid 90s inland with peak heat index values generally around 100 to 107 degrees. These values appear to remain just below local heat advisory criteria, but heat stress will still be an issue for outdoor activities.

On Sunday, an upper trough will begin digging into the southeastern U.S., breaking down the eastern side of the ridge and the portion over the local area. This should support higher rain chances Sunday into Tuesday, with the same general summertime rhythm of nocturnal to morning convection near the coast and coastal waters, then inland convection during peak heating. Severe weather potential remains low given weak shear, but isolated gusty winds and frequent lightning will remain possible with the stronger storms.

MEFFER

LONG TERM

(Wednesday through Friday night) Issued at 133 PM CDT Sat Jul 4 2026

The upper trough over the Southeastern US should lift northeast by Wednesday, allowing ridging from the west to expand back eastward across the lower Mississippi Valley and central Gulf Coast. At the surface, weak ridging should remain the dominant feature across the Gulf region. This favors a trend toward somewhat lower rain chances compared to the Sunday through Tuesday period, but not a dry forecast. Sufficient Gulf moisture and daytime heating should still support isolated to scattered mainly afternoon showers and thunderstorms, especially along sea breeze and differential heating boundaries.

With heights rising again, heat will likely become the more persistent hazard concern late week. Highs should remain in the lower to mid 90s with humid conditions keeping afternoon heat indices in the 100 to 107 degree range, locally near advisory levels depending on cloud cover and storm timing. Confidence in widespread advisory criteria exceedance is not high enough at this range, but heat impacts will remain possible for outdoor work and recreation.

MEFFER

AVIATION

(18Z TAFS) Issued at 133 PM CDT Sat Jul 4 2026

VFR conditions are expected to dominate through most of the period. Afternoon TSRA will be the main aviation concern, with KHUM, KMSY, and KNEW the most likely terminals to be affected. Any storms moving over a terminal could briefly produce MVFR or lower visibility, gusty/erratic winds, and lightning. Confidence in exact terminal impacts remains limited, so PROB30/TEMPO handling would be favored where convection appears most likely. Convection should diminish this evening with mainly clear/VFR conditions overnight. Winds outside storms should remain light and variable.

MEFFER

MARINE

Issued at 133 PM CDT Sat Jul 4 2026

Surface ridging over the Gulf will maintain a weak pressure gradient, supporting a typical summertime marine pattern. Therefore, expect generally less than 10 kt winds and seas/waves 2 feet or less to continue across the coastal waters.

Marine convection remains the primary concern. Thunderstorms will be favored mainly overnight through mid morning over the waters, with additional activity possible near coastal boundaries during the afternoon. Any storms could produce frequent lightning, locally higher winds, and brief hazardous seas. The waterspout environment appears favorable today, especially where showers or developing storms interact with weak boundaries in the low-shear environment.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

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