Slidell, LA Weather

Key Messages

Updated at 550 AM CDT Tue Oct 20 2026

- Conditions will remain somewhat favorable for the spread of fires through the remainder of this week due to low humidity and drought/abnormally dry conditions across most of the area.

- Conditions will remain hazardous to small craft across most coastal waters in southeastern Louisiana and Mississippi due to moderate to strong winds and high waves/choppy to rough seas. Exercise caution headlines will remain in place through at least Tuesday morning for most coastal waters.

Short Term

(Now through Friday) Issued at 1238 AM CDT Tue Oct 20 2026

The forecast is relatively quiet and generally a temperature forecast through much of the week. The ridge build over the western Gulf and TX coast will slide west and continue to build over the next few days. By Wednesday afternoon the ridge will be centered over northern Mexico with the ridge xis extending north just east of the Rockies. This will place the area under deep northwest flow Wednesday and by Thursday as the ridge continues to build north we will move under northerly flow which will dominate the area into the weekend. At the sfc high pressure will continue to dominate the region and remain centered well to the north. The gradient will slack off leading to lighter winds but given the northwesterly to northerly flow aloft and high pressure at the sfc leading to easterly flow there will be no moisture recovery and thus no rain in the forecast. LL temps will slowly climb with h925 temps around 18C by Thursday. This will lead to afternoon highs climbing into the mid to upper 80s by Friday. The increase in afternoon temps and lack of moisture recovery will continue to lead to RH values dropping a little more each day and thus elevated fire weather concerns. Luckily winds will remain on the light side. /CAB/

Long Term

(Friday night through Monday) Issued at 1238 AM CDT Tue Oct 20 2026

Upper level troughs will extend from the Canadian Maritime Provinces to near Savannah to the central Gulf, and over the Intermountain West, with ridging from Texas to the upper Mississippi River Valley on Friday night. Surface high pressure over northern Maine will extend southwestward into Texas, controlling the weather over the eastern half of the country.

The ridging will be centered over the Gulf on Monday, with an upper trough developing over the Texas/Oklahoma Panhandles. Surface high pressure will be continuing to control the weather across the area through the weekend into early next week. The current wind forecast doesn't show any indications of winds becoming primarily onshore through early next week. This means no significant moisture return, which is reflected by forecast precipitable water values remaining below 1 inch, and generally at the 25th percentile or less, climatologically. This will keep any significant precipitation well offshore through the weekend into early next week.

Temperature-wise, the warming trend from earlier in the week will continue as the continental airmass gradually modifies beneath the ridge. Highs will generally reach the upper 70s (coastal areas) to mid 80s (inland) across the area through the weekend, with some locations around Baton Rouge potentially approaching 90 degrees. That's probably the upper end though, as the 90th percentile at Baton Rouge at the end of the week is 89. With plenty of sunshine and relatively dry air still in place, expect some rather large diurnal temperature ranges, especially across southwest Mississippi and the Florida Parishes. Overnight lows should generally fall into the low to mid 50s across the inland portions of the area, with upper 50s and low 60s closer to the coast and southshore. Won't rule out a few upper 40s in the normally cooler locations. /RW/

Aviation

(12Z TAFS) Issued at 550 AM CDT Tue Oct 20 2026

VFR conditions continue to occur at all terminals and will persist through the forecast. That said there may be a few times where low clouds could temporarily move overhead but even those will be few to sct with cigs will likely above 3k. /CAB/