textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 139 PM CDT Tue Jun 30 2026

- Heat index values will be in the 105 to 110 range for most areas today and a heat advisory has been issued. Those with outdoor plans or work should take precautions to avoid heat- related iillnesses. Drink plenty of water, wear light- weight and loose- fitting clothing, and take breaks in the shade or air conditioning during the afternoon hours.

- Daily scattered to numerous showers and storms with the highest chances on Wednesday. Widespread severe weather and heavy rain will be low, a few storms each day could become strong to severe gusty winds and/or locally heavy rainfall. The potential will exist for waterspout and tornado activity as well.

SHORT TERM

(Now through Friday night) Issued at 139 PM CDT Tue Jun 30 2026

Broad scale 594dm ridge is currently encompassing pretty much all of the southeastern US. The center is a few hundred miles northeast of the CWA but plenty close enough for subsidence to hinder convective development. The GFS is pretty bullish in that it indicates late evening complex developing INVOF the Florida Panhandle out of discrete cells before tracking west along the northern Gulf Coast and into the local area late evening. Some CAMs do acknowledge some potential of this easterly wave but generally agree that storms dissipate before reaching the CWA. A slight drift of the center of the upper high to the northeast Wednesday looks open the door per se to development of afternoon storms. At the same time, that easterly wave will bring a localized increase in atmospheric column moisture. The POPs forecast of 50-80% accounts for those 2 changes. Will certainly have to keep an eye out for marginally severe downbursts.

The arguably more impactful weather hazard though is heat. 500mb heights what they are and will be tomorrow combined with mid/upper 70 degree dewpoints in place. Heat Advisory in effect today will be extended through Wednesday. Storms that develop will provide relief but later day initiation means many hours of heat indices 108+ for many locations.

MEFFER

LONG TERM

(Saturday through Monday night) Issued at 139 PM CDT Tue Jun 30 2026

Looks like a pretty typical summertime pattern for the remainder of the weekend and going into the holiday weekend. Global models show northern stream trough tracking across the country will aide in transition of upper ridge centered over the southeast US to the Desert Southwest. In doing so, locally we'll lose inhibition thats been limiting storm coverage lately. Many days this upcoming week will see storms developing initially along seabreeze convergence boundaries. Once those storms becoming mature and then outflow dominate, they'll spread to other portions of the local forecast area. Areas that don't see storm development until later in the day will be more likely to approach heat advisory criteria.

MEFFER

AVIATION

(18Z TAFS) Issued at 139 PM CDT Tue Jun 30 2026

VFR will prevail outside remain through the daylight hours. By the evening hours, TSRA will be developing and moving west bringing IFR cigs and vis temporarily to terminals over coastal Miss initially and sites to the west as the evening progresses. As the high currently over the area moves out and the easterly wave moves in, there could be some vertical wind shear created by the late afternoon hours and could make for a bit of weak CAT. Once TSRA start developing, shear values will be highest in and around them.

MEFFER

MARINE

Issued at 139 PM CDT Tue Jun 30 2026

Aside from a weak easterly wave moving through the northern Gulf overnight tonight, the pattern will be dominated by high pressure influences. Winds will generally be 10kts or less and direction will vary through midweek, becoming more predominantly southerly as high pressure builds over the eastern Gulf late in the week. The overall gradient is relatively weak which is why winds struggle to exceed 10 kts and seas/waves mostly under a couple feet. Generally isolated to scattered showers and storms can be expected each day, with potential for more numerous/widespread convection on Wednesday associated with the easterly wave. A few stronger storms could produce gusty winds and/or waterspouts, and locally hazardous seas during the second half of the work week.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

LA...Heat Advisory until 6 PM CDT this evening for LAZ034>037-039- 046>048-056>058-064-070-071-076>087-089>100.

Heat Advisory from 10 AM to 6 PM CDT Wednesday for LAZ034>037- 039-046>048-056>058-064-070-071-076>087-089>100.

GM...None. MS...Heat Advisory until 6 PM CDT this evening for MSZ068>071-077- 083>088.

Heat Advisory from 10 AM to 6 PM CDT Wednesday for MSZ068>071- 077-083>088.

GM...None.