textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 548 AM CDT Sun May 31 2026

- Drier pattern through Tuesday with increased rain chances returning late in the week.

- Summertime temps are here with highs around 90 degrees and heat indicies of 100 to 105 through Tuesday.

SHORT TERM

(Now through Wednesday) Issued at 1253 AM CDT Sun May 31 2026

No significant changes in thinking from the previous forecasts as a broad ridge axis dominates the region through Tuesday. Temperatures will continue to run several degrees above average in the upper 80s along the immediate coast and the low to mid 90s further inland as subsidence aloft warms the overall atmosphere. As these temperatures climb, heat index values will rise to between 100 and 105 degrees each afternoon through Tuesday. Although these heat index values are lower than our heat advisory issuance criteria, the early season nature of this heat could induce higher heat illness impacts than typically seen later in the Summer months when the population has become more acclimated to the hot conditions. This is reflected well by the area being in moderate to major HeatRisk today, tomorrow, and Tuesday. Major HeatRisk indicates that the broader population will be at risk of heat illness if proper precautions are not taken.

Beyond the heat impacts, the pattern will also be very Summer like in terms of convective potential. Although there will be some warming in the mid-levels, lapse rates and overall mixed layer CAPE values will favor some diurnally induced convective activity each afternoon. The convection will tend to develop along the seabreeze boundary or other weak convergence boundaries and then spread outward on new outflows through the afternoon hours. As daytime heating wanes and CAPE decreases in the evening hours, the convective activity will quickly dissipate today and tomorrow. Most of the convection will remain on the weaker side, but a few storms could develop deeper updrafts and turn strong. These deeper updrafts could entrain some drier mid-level air and a few wet microbursts cannot be ruled out today, tomorrow, and Tuesday. This is supported by DCAPE values of around 1000 J/KG.

A weak backdoor cold front associated with a strong longwave trough axis digging into the eastern seaboard Tuesday night and Wednesday will sweep through the region and then stall just offshore in the coastal waters. A line of showers and thunderstorms should accompany the front as it pushes through Tuesday night and a few of these storms could also turn strong with gusty winds being the main concern. As northeast flow develops behind the front both cold and dry air advection will take hold. PWATS will fall significantly to less than 1.25 inches, and this will greatly limit convective potential over most of the forecast area on Wednesday. The only area where some scattered convection may try to develop would be along the Louisiana coast where a suppressed seabreeze could help to spark off some weaker storms in the late afternoon hours. Otherwise, a largely clear and dry day should be on tap for the region. The weak cold air advection will also allow temperatures to cool back to average in the mid to upper 80s and heat index values will drop back into the low 90s on Wednesday. Thus, the heat illness concerns will diminish for the broader population, but will continue for those most vulnerable to warm temperatures.

LONG TERM

(Wednesday night through Saturday) Issued at 1253 AM CDT Sun May 31 2026

Upper ridging will be building across the lower Mississippi River Valley by Wednesday night, and is likely to remain over or near the local area at the end of the week into the weekend. The ECMWF and GFS operational runs from 12z Saturday aren't in agreement on timing and location but are fairly close on the general scenario. The ECMWF is somewhat further north with the center of the ridging, which would keep the convection that fires around the periphery of the ridge well away from us, while the GFS solution would have organized convection closer to the local area. Precipitable water values look to rebound from levels early in the week by Thursday and probably be well above the 75th percentile at the end of next week and over next weekend. With abundant moisture available, we'll expect scattered diurnally favored convection (daytime over land, night over water). No indications of a mid-level cap on forecast soundings yet. That is about the only thing that could significantly hinder storm development.

The deep trough off the Atlantic Coast may pull a front into the area at midweek, bringing slightly cooler and drier air to the area for about 48 hours. But we're only talking mid 80s for highs and mid to upper 60s for lows vs. highs in the upper 80s to lower 90s and lows in the upper 60s to lower 70s. Any adjustments in temperatures in the long term period would only be a degree or two at most, so we are unlikely to make adjustments. If nothing else, that should lower the heat risk for the local area for a few days around Thursday and Friday.

AVIATION

(12Z TAFS) Issued at 548 AM CDT Sun May 31 2026

Light fog at MCB will quickly burn off in the next 1 to 2 hours as temperatures rapidly climb. Once this fog clears, prevailing VFR conditions will be the rule at all of the terminals today. There is a very low chance of a thunderstorm forming near GPT or MCB this afternoon, but the chances are too low to include in the forecast. Later tonight, another round of light fog may push visibilities down to 3 to 5 miles at MCB after 10z as another weak surface based temperature inversion forms.

MARINE

Issued at 1253 AM CDT Sun May 31 2026

A broad area of high pressure will keep conditions over the waters relatively benign. Winds will be light at 10 knots or less and seas will remain below 2 feet. The seabreeze cycle will lead to some variability in wind direction near the coast, and a few thunderstorms could fire up in relation to this seabreeze/landbreeze cycle. Any storms will be short-lived and will produce locally gusty winds and lightning. A weak cold front is still expected to slip into the waters Tuesday night into Wednesday. Winds will turn northeasterly and increase to 10 to 15 knots in the wake of this weak front. Thunderstorm activity will be a bit more widespread as the front moves through, and a few stronger storms with high wind gusts could develop. By Thursday and Friday, the front will dissipate and a return to a prevailing southeast wind is expected. However, the pressure gradient over the northern Gulf will tighten up as a low forms over the western Gulf and a broad high remains centered over the Southeastern states. This will push winds into the 15 to 20 knot range by the end of the week and seas will increase to 3 to 5 feet.

LIX WATCHES/WARNINGS/ADVISORIES

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