textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1254 PM CDT Tue Apr 28 2026

- Well above average high temperatures in the upper 80s and lower 90s will continue through Wednesday. Heat index values will climb into the lower to mid 90s.

- There is a Marginal Risk for heavy rainfall late Wednesday and again on Friday.

- The threat for thunderstorms, some possibly strong to severe will start Wednesday and continue through the weekend.

SHORT TERM

(Now through Wednesday night) Issued at 1254 PM CDT Tue Apr 28 2026

That upper-level ridge that has been anchored over Mexico and expanded north across the southern US losing its northern extent today as a trough pass across the Great Lakes. That'll put the CWA on the northern periphery the ridge but still have sufficient ridging aloft to support anomalously warm temps. A trailing shortwave moving through the Central Plains will enhance thunderstorm development along frontal boundary already in place from the leading trough. Then, like it previous recent days, supercells will congeal into an MCS and ride the northern periphery of the upper ridge tonight. CAM solutions obvious vary from one another but the general consensus is that stronger convection will remain north of the CWA and what does make it into southwest MS and southeast LA will be in a non-impactful decaying state.

That trailing shortwave will become absorbed by a much broader upper level trough from the north as it amplifies and digs southward. Still not enough ridge suppression locally to bring down temps much but will start the return of increased rain chances. Another shortwave on tracking along the southwestern edge of the broad scale trough. That'll help drive it down farther south Wednesday and then in-tern bring associated cold front into the northern portions of the CWA. Model sounding in southwest MS indicates some severe potentially late in the day. Shear is modest but CAPE is well beyond sufficient. Gusty winds and hail look to be the primary threats. Late timing of the front moving in will likely nearly eliminate severe potential I-10/12 corridors and southward. One caveat, if convection development occurs mid afternoon, could see some decent elevated storms from BTR to ASD.

As the main trough axis passes east of the CWA, the base of it pulls northward. That puts the CWA in more of a zonal flow pattern. So wherever the cold front ends up by then is probably were it will stay for the time being. High temp gradient across the local area will be much higher than typical, ranging from mid/upper 70s north of the boundary to mid 80s south of it. Scattered showers and possibly some thunderstorms will develop through out the day.

MEFFER

LONG TERM

(Thursday through Monday night) Issued at 1254 PM CDT Tue Apr 28 2026

Southwesterly flow increases in the mid and upper levels overhead Friday as an upper level low comes into the southwestern US, reaching the 4 Corners region late in the day. This setup will first lead to a fairly substantial cirrus deck over the CWA Friday. That, combined with east to northeast surface flow will yield even cooler highs. Will be the first time in about a week that highs struggle to reach climatological normal. Friday night into Saturday though, rain chances come up considerably and upper low/trough moving across TX will provide conditions much more conducive for widespread shower development over the local area. A more substantial shortwave coming around the base of the upper level trough still situated northeast of the region will drive the cold front well into the Gulf and bring much cooler air to the local area Saturday night through Monday.

MEFFER

AVIATION

(18Z TAFS) Issued at 1254 PM CDT Tue Apr 28 2026

MVFR to VFR conditions will prevail this afternoon with modest winds gusting in the teens. Main impact tonight is a few terminals seeing MVFR visibilities and IFR decks as the night progresses. Early evening storms could push into KMCB area but confidence is not particularly high with that coming to fruition.

MARINE

Issued at 1254 PM CDT Tue Apr 28 2026

Persistent onshore flow of 10 to 15 knots will remain in place through tomorrow with high pressure generally centered east of the local coastal waters. Seas will remain well below any hazardous limits at 1 to 3 feet through this period. As we move into the back half of the week, we will see a weak cold front drift south towards the coast and stall along the northern Gulf Coast. That'll lead to both weaker winds overall as well as north or south winds depending on coastal zone's location in related to the boundary. A stronger upper level trough moves through the region Saturday morning. Expect to see at least Exercise Caution, possibly low in Small Craft Advisory, conditions behind this front.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

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