textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1123 PM CST Tue Nov 25 2025 - A substantial cool down Thursday and Friday nights with temperatures in the 30s and 40s. A few places could briefly touch freezing across SW MS, and within the Pearl and Pascagoula River drainage areas.

- Hazardous conditions for small craft through Thursday, possibly through the entire weekend.

- Rain threat increases for the weekend and early next week. The rain could be locally heavy at times.

SHORT TERM

(Tonight through Friday night) Issued at 1123 PM CST Tue Nov 25 2025

A strong longwave trough axis over the eastern third of the CONUS will be the primary feature impacting the Gulf South through Thursday. The trough will begin to lift on Friday and a more zonal flow pattern will take hold. The region will be embedded beneath a deep layer northwest flow regime today and tomorrow, and this will usher in both a very dry and significantly colder airmass from the northern Plains and southern Canada. A review of model soundings over the next three days indicates that PWATS will run between 0.20 and 0.30 inches, or between the minimum and 10th percentile for this time of year. This dry airmass will keep skies clear through Friday night and allow for a larger diurnal temperature range. Although a 925mb thermal trough axis will be moving into the region, daytime highs will still manage to climb to near average values Wednesday afternoon. However, a good 30 to 35 degree drop in temperatures is expected Wednesday night as winds relax and strong radiational cooling beneath those clear skies occurs. Overnight lows will easily fall into the upper 30s and lower 40s over inland areas and the upper 40s in metro New Orleans and along the coast. Thursday and Friday will be the coolest days of the short term period as the heart of the thermal trough axis slides through the region. 925mb temperatures are only supportive of highs in the upper 50s and lower 60s or 5 to 10 degrees below average. This cooler start will allow overnight lows to rapidly cool into the lower to middle 30s over inland areas and the lower 40s south of the lake and along the coast. Widespread frost and even the potential for a light freeze in the Pearl and Pascagoula River drainages is probable for Thursday and Friday night.

LONG TERM

(Saturday through Tuesday night) Issued at 1123 PM CST Tue Nov 25 2025

The zonal flow pattern in the mid and upper levels that begins to take shape on Friday will be the predominant pattern in place over the weekend and into early next week. A very progressive pattern of southern stream shortwave troughs and associated surface low pressure systems will bring higher rain chances and warmer temperatures to the area over the weekend. However, forecast spread between the various models increases dramatically as we move into the first half of next week. This has resulted in a nearly 20 to 25 degree spread between the 25th and 75th percentiles on Monday and Tuesday. The main concern will be if a backdoor cold front is able to clear the coast early next week. If the front pushes offshore, temperatures will easily fall back below normal. However, if the front stays to the north, a much warmer and stormier pattern could emerge next week. Given the amount of uncertainty in the forecast, the best option was to stick with the ensemble NBM solution on Monday and Tuesday.

On Saturday and Sunday, the latest models have come into good agreement that a vigorous shortwave trough and associated surface low will approach the region on Saturday and pass through the area on Sunday. Winds will turn southerly on Saturday a surge of Pacific based moisture will feed into the region. Additional low level moisture advection Saturday afternoon into Saturday night will further deepen the available moisture pool and PWATs will rise to between 1.2 and 1.4 inches or the 75th and 90th percentiles by Saturday night and Sunday. These very high values will support periods of rainfall. Although overall instability will be largely elevated and somewhat limited, enough forcing will be in place to support a few thunderstorms. Overall, a very gray and rainy day is expected on Sunday. Rainfall could be locally heavy at times, and rainfall totals could be as high as 2 to 3 inches in a few locations by Sunday night. Given the dry conditions in place, this will be a beneficial rainfall for the area. Temperatures will also respond to the southerly flow and increased moisture. Highs will be near average on in the upper 60s and lower 70s this weekend, but the surge of moisture will keep lows warmer than average Saturday night.

All of the models show another trough impacting the area Monday into Tuesday. Confidence is higher that continued higher than average rain chances will persist on these days. However, that is the only area where forecast confidence is at least average for the day 6 and 7 period. As mentioned before, the temperature forecast is highly uncertain and the deterministic NBM output was used to produce the forecast for early next week.

AVIATION

(06Z TAFS) Issued at 1123 PM CST Tue Nov 25 2025

Some patchy fog and low ceilings developed over the past 2 to 3 hours at a few more coastal terminals including HUM, ASD, and GPT right in advance of a dry air surge as temperatures cooled to the dewpoint. The ceilings and fog will begin to clear over the next couple of hours as the drier air moves in. Boundary layer winds will also be on the increase, and this will keep conditions unfavorable for fog redevelopment later tonight. As a result, VFR conditions are expected at all of the terminals from 08z onward. Winds will be gusty at NEW, GPT, HUM, and MSY as a cooler airmass advects over the warmer nearshore waters. PG

MARINE

Issued at 1123 PM CST Tue Nov 25 2025

A cold and dry high pressure system will build over the waters through Friday. As this colder and drier air moves across the warmer waters, stronger winds aloft will transport down to the surface. As a result, an extended period of small craft advisory conditions due to northerly winds of 20 knots or greater and rough seas of over 7 feet will impact the waters through Friday. Winds will relax slightly to between 15 and 20 knots and begin to turn more southeasterly and southerly over the weekend as another low pressure system pushes through the region.

PRELIMINARY POINT TEMPS/POPS

MCB 51 63 36 60 / 0 0 0 0 BTR 54 67 39 62 / 0 0 0 0 ASD 53 70 38 63 / 10 0 0 0 MSY 59 69 48 63 / 10 0 0 0 GPT 56 71 43 63 / 20 0 0 0 PQL 54 71 37 63 / 30 0 0 0

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Small Craft Advisory until noon CST Thursday for GMZ530-532-534- 536-538-550-552-555-557-570-572-575-577.

MS...None. GM...Small Craft Advisory until noon CST Thursday for GMZ532-534-536- 538-550-552-555-557-570-572-575-577.