textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1112 PM CST Fri Nov 28 2025 - Hazardous marine conditions for much of the next 5 days. - Entering a wetter pattern beginning Saturday night into Sunday, with additional periods of rainfall, possibly heavy, Monday night into Tuesday, and possibly again on Thursday.

SHORT TERM

(Tonight through Monday night) Issued at 1112 PM CST Fri Nov 28 2025

A zonal flow regime will remain in place through Sunday across the Gulf South. In the low levels, the region will find itself placed between a departing high and an advancing front the next couple of days. Winds will veer to a more southeasterly direction and temperatures will warm back to more average readings for this time of year with highs in the upper 60s and lower 70s Saturday afternoon. This southeast flow off the Gulf will also bring moisture back into the region. PWATS will increase dramatically throughout the day and will be around the 75th percentile by Saturday evening. This will be most noticeably marked by a gradual lowering of the cloud deck through the day as moisture deepens. By late Saturday night into Sunday, a fast moving shortwave trough axis and the aforementioned frontal boundary will begin to slide through the region. Ample deep layer forcing and moisture will support a broad area of post-frontal stratiform rainfall development from late Saturday night into Sunday. Rainfall totals of a half inch to up to an inch are probable with this weekend rain event.

By Sunday night, the front is expected to stall over the northern Gulf as the parent shortwave feature quickly lifts to the northeast. Mid-level flow will remain southerly to southwesterly, and this will allow for weak isentropic forcing over the cooler and more stable surface based airmass to linger through Monday morning. Skies will remain overcast and isolated light rain showers will persist over the area due to this isentropic forcing. Temperatures Sunday into Sunday night will see a wide gradient with readings only rising into the upper 50s and lower 60s north of the front in southwest Mississippi and the Baton Rouge metro, but readings also climbing into the upper 60s and lower 70s in coastal Mississippi, metro New Orleans, and coastal Louisiana. Lows will also see a decent gradient with the front stalled on the Louisiana coast with readings dropping into the 40s north of I-10 and lower 50s south of I-10 Sunday night. A very similar temperature spread is expected Monday into Monday night as the frontal boundary remains stalled just offshore.

A much stronger southern stream system embedded within the broader zonal flow pattern will push through the area Monday into Monday night. Very strong and deep forcing will be in place as both a highly difluent pattern aloft and favorable jet dynamics develop over a region of enhanced baroclincity in the northern Gulf. A Gulf low will form on Monday beneath these favorable upper level dynamics, and this low will pass directly through the region Monday night. The isentropic forcing over the cooler surface based airmass to the north of the stationary front will also contribute to the deep layer forcing across the area. All of these factors will support widespread moderate to heavy stratiform rainfall from Monday afternoon through Monday night. PWATS are forecast to rise to daily max value of around 1.5 inches, and heavy rainfall will be a concern. Rainfall totals of 1 to 3 inches could occur.

One area of concern for any surface based convection and a low end threat of strong to severe storms could be over the eastern Gulf waters and potentially as far north as coastal Mississippi late Monday afternoon into Monday evening. This will be highly dependent on the exact track of the deepening Gulf low, so uncertainty is greater than average. However, a review of model soundings in the area indicate marginally conducive shear and instability parameters over the aforementioned time period. As more high resolution model data comes in, forecast confidence any the evolution of the low and any surface based convective threat will increase. To the immediate north of the front, mid- level lapse rates may support an isolated elevated thunderstorm within broader stratiform rain shield in coastal Louisiana, but thunderstorm chances diminish to near zero closer to the I-10 corridor.

LONG TERM

(Tuesday through Friday night) Issued at 1112 PM CST Fri Nov 28 2025

Model guidance remains in good agreement that a cooler and drier airmass will quickly advect into the area on Tuesday as the Gulf low and attendant cold front sweep well east and south of the region. These conditions will linger into Wednesday as a surface high passes to the north of the area. Highs will only climb into the mid 50s Tuesday afternoon and overnight lows will easily fall below freezing along and north of the I-10/12 corridor. The cold temperatures will continue into Wednesday with highs only rising into the upper 50s and lower 60s.

This brief break in a more unsettled pattern will be short-lived as the model guidance is in decent agreement that another fast moving shortwave trough embedded with the persistent zonal flow pattern aloft will begin to impact the area on Thursday. Model spread begins to increase as we move into Friday and Friday night, and overall forecast confidence decreases dramatically. It does look like a return to a wetter period of weather will occur on Thursday and Friday, and have opted to largely stick with the NBM output for both days. This results in PoP of 40 to 60 percent over this period. Temperature spreads are also large as the positioning of a frontal boundary over the area has large spatial differences. NBM deterministic output has readings running slightly cooler than average with highs the 50s and 60s and lows in the 40s and 50s, and have stuck with this for day 6 and 7 forecast.

AVIATION

(06Z TAFS) Issued at 1112 PM CST Fri Nov 28 2025

VFR conditions will be the rule even as overall mid and high level cloud cover increases. Winds will remain gusty at over 12 knots from a general easterly component at NEW through the period due to continued thermal mixing of stronger winds aloft down to the surface over the warmer lake waters.

MARINE

Issued at 1112 PM CST Fri Nov 28 2025

East winds of around 20 knots will begin to ease Saturday afternoon and will remain below advisory criteria at 10 to 15 knots through Sunday afternoon. Sunday night through Tuesday will see more hazardous conditions for small craft return as a low pressure system passes through the coastal waters. Northerly winds will increase back above 20 knots and seas will rise back to 5 to 7 feet in the open Gulf waters. As high pressure briefly builds back over the waters Tuesday night into Wednesday, winds will turn more easterly and weaken to between 10 and 15 knots. Seas will also subside back to 1 to 3 feet as these calmer winds take hold.

PRELIMINARY POINT TEMPS/POPS

MCB 38 66 50 58 / 0 10 60 70 BTR 42 70 55 62 / 0 10 60 70 ASD 39 69 55 70 / 0 0 20 40 MSY 50 70 60 70 / 0 0 20 40 GPT 43 67 56 71 / 0 0 10 40 PQL 37 67 54 71 / 0 0 10 30

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Small Craft Advisory until noon CST Saturday for GMZ550-552-555- 557-570-572-575-577.

MS...None. GM...Small Craft Advisory until noon CST Saturday for GMZ552-555-557- 570-572-575-577.