Area Forecast Discussion

KEY MESSAGES

Updated at 1043 PM CST Tue Nov 3 2026

- Dense fog is expected tonight into Wednesday morning, especially across the Northshore and coastal Mississippi. Visibilities could drop to 1/4 mile or less in some areas.

- A few showers and thunderstorms are possible overnight into Wednesday morning as a cold front moves through. Drier and more pleasant conditions will follow through Thursday.

- Another weak front will move through Friday, followed by a stronger front this weekend. Cooler and much drier conditions are expected heading into early next week.

SHORT TERM

(Now through Saturday night) Issued at 1043 PM CST Tue Nov 3 2026

The main concern in the short term will be the dense fog developing tonight, followed by a couple of cold fronts that will bring cooler and drier conditions through the weekend.

Starting with tonight, plenty of low-level moisture remains in place ahead of the approaching cold front. As winds become light to calm, the saturated boundary layer will allow fog to develop across portions of the area. The greatest concern will be across the Northshore and coastal Mississippi where the combination of radiational cooling, moisture pooling ahead of the front, and the influence of the nearby Gulf waters will support more widespread dense fog. Because of this, a Dense Fog Advisory is now in effect for Washington and St. Tammany Parishes as well as Pearl River, Hancock, Harrison, and Jackson Counties through 8 AM Wednesday. Visibilities could drop to 1/4 mile or less, particularly during the early morning hours. The main thing that could disrupt the fog will be the approaching front and any showers or increases in winds associated with it.

Speaking of the front, the negatively tilted 500mb trough currently moving across the Mississippi Valley will continue progressing northeast overnight. Although sufficient forcing exists to support a line of showers and a few thunderstorms, the best dynamics remain displaced well north of our area. Therefore, convection should continue weakening as it progresses eastward, with the greatest rain chances generally across southwest Mississippi and the Baton Rouge area. Most locations farther east should see little precipitation. The front should move through Wednesday morning, bringing northwest winds and drier air into the area. This will help clear out any lingering fog and low clouds, with improving conditions throughout the day.

By Wednesday night, shortwave ridging will move across the area and allow surface high pressure to briefly take over. This will bring a rather substantial decrease in deep-layer moisture, with PW values potentially falling to around 0.5-0.75 inches. With the much drier airmass, mostly clear skies, and light winds, efficient radiational cooling should take place Wednesday night. Looking at the latest NBM guidance, skies should clear fairly quickly behind the front with winds becoming light overnight. Therefore, minimum temperatures were lowered Thursday morning to account for the favorable cooling conditions. Lows should generally fall into the low to mid 50s across the northern areas with upper 50s and low 60s closer to the coast. Thursday will be rather pleasant with highs in the upper 70s and low 80s as plenty of sunshine returns.

However, another fast-moving shortwave will approach Thursday night into Friday, bringing our next weak cold front. Unlike the previous system, the main question will be whether sufficient moisture can return ahead of this feature to produce any meaningful precipitation. With such a short period between fronts, the better moisture looks to remain confined to areas along and south of I-10. Therefore, isolated to scattered showers will be possible across the southern portions of the area Thursday night into Friday, while most northern locations remain dry. Instability will be rather limited with weak mid-level lapse rates, so thunderstorm activity should be minimal.

The other forecast challenge Friday will be temperatures. With most guidance favoring mostly clear skies across the northern half of the area, maximum temperatures were increased slightly there to account for better daytime heating. Highs should generally reach around 80 to the lower 80s across the northern areas, with upper 70s closer to the coast where more cloud cover is expected. Minimum temperatures Friday morning were also increased slightly along the coast due to the expected increase in cloud cover ahead of the shortwave limiting radiational cooling.

As the aforementioned trough moves east Friday night, another reinforcing front will push through the area and bring another round of dry air advection. This should effectively end any lingering precipitation chances and bring cooler temperatures for Saturday. Highs should generally only reach the low to mid 70s with mostly dry conditions across the area. Another surge of northerly flow will reinforce the cooler airmass Saturday night, with lows falling into the low to mid 40s across the northern half of the area and remaining in the 50s closer to the coast.

LONG TERM

(Sunday through Tuesday night) Issued at 1043 PM CST Tue Nov 3 2026

The main forecast challenge in the long term will be what happens with the southern-stream trough across the southwestern CONUS, as guidance continues to struggle with its evolution. The biggest question is whether this trough is able to eject northeastward across the lower Mississippi Valley on Sunday or if it becomes cut off over the Baja region. These two scenarios would have rather different implications for our sensible weather, particularly precipitation chances Sunday into early next week.

Looking at the latest 00Z deterministic guidance, the GFS favors a more progressive solution with the southern-stream trough ejecting across our area Sunday. This would provide sufficient synoptic forcing for surface low pressure development along the northern Gulf Coast and potentially bring some precipitation into the area. Meanwhile, the ECMWF favors cutting off the southern portion of the trough over Baja, effectively delaying its eastward progression and keeping the better forcing well to our west. This would allow more subsidence and surface high pressure to remain over our area, keeping conditions predominantly dry. Given these differences, confidence in precipitation chances Sunday remains rather low.

Even if the more progressive solution comes to fruition, the other question will be how much moisture is available for this system to work with. The reinforcing cold front moving through Saturday will bring a much drier continental airmass into the area, which could make sufficient moisture return difficult. Therefore, even with better forcing, precipitation may remain confined to areas along the coast and offshore waters. However, if surface low pressure develops farther north along the coast, better low-level moisture and convergence could extend precipitation chances farther inland.

Beyond Sunday, the forecast will largely depend on which solution plays out. If the trough ejects across the area, subsidence and surface high pressure should build back in behind it Monday and Tuesday, bringing mostly dry conditions. However, if the southern- stream energy remains cut off farther west, the next opportunity for precipitation would be delayed until that energy eventually progresses eastward. Regardless, temperatures should generally remain near seasonal averages with highs in the upper 60s to 70s and lows in the 40s across northern areas and 50s closer to the coast. Some moderation will be possible into Tuesday as the cooler airmass gradually modifies.

AVIATION

(06Z TAFS) Issued at 1043 PM CST Tue Nov 3 2026

The main aviation concern throughout this TAF period will continue to be low ceilings and fog overnight into Wednesday morning. IFR conditions are already affecting several terminals, with LIFR conditions at GPT where dense fog has reduced visibilities to 1/4SM and ceilings to around 200 ft. With plenty of low-level moisture in place and winds generally light to calm, IFR to LIFR conditions will remain possible through the morning hours, especially at GPT, ASD, and MCB. A few showers will also be possible overnight, primarily at BTR and MCB, which could temporarily lower ceilings and visibilities even further. As a cold front moves through the area Wednesday morning, winds will gradually become more northwesterly and drier air will begin filtering in. This, along with daytime mixing, should allow conditions to improve back to VFR at most terminals between 14-18Z, although GPT may hold onto dense fog until around 15Z. A few additional showers will be possible Wednesday afternoon across the eastern terminals, but coverage should remain rather limited.

MARINE

Issued at 1043 PM CST Tue Nov 3 2026

Light south to southwest winds around 5 to 10 kt will continue through tonight ahead of an approaching cold front. The main concern tonight will be dense fog, especially across the Mississippi Sound, Lake Borgne, and Chandeleur Sound, where visibilities could fall below 1 NM. Dense Fog Advisories are in effect for portions of these waters through Wednesday morning. A few showers and thunderstorms will also be possible as the front moves through Wednesday, with winds shifting to the northwest behind it. However, the pressure gradient will remain rather weak, so winds should stay relatively light through Thursday as surface high pressure moves across the waters. Another weak front will move through Friday with some scattered showers possible, mainly across the southern waters. A stronger reinforcing front will follow Friday night into Saturday, bringing increasing north to northeast winds around 10 to 15 kt, with some winds approaching 20 kt across the outer waters Saturday night. Another increase in northerly winds is expected Sunday into Sunday night, potentially reaching Small Craft Advisory criteria as seas build.

LIX WATCHES / WARNINGS / ADVISORIES

LA...Dense Fog Advisory until 8 AM CST Wednesday for LAZ039-076-079- 080.

GM...Dense Fog Advisory until 10 AM CST Wednesday for GMZ532-534.

MS...Dense Fog Advisory until 8 AM CST Wednesday for MSZ077-083>088.

GM...Dense Fog Advisory until 10 AM CST Wednesday for GMZ534.