South Vacherie, LA Weather

Key Messages

Updated at 1215 PM CDT Mon Oct 26 2026

- Elevated fire danger will continue through mid-week. The ongoing drought conditions and dry fuels combined with low humidity and light to moderate winds will lead to potential for some fire spread. Residents should obey all burn bans in place and exercise extreme caution with any open flames outdoors even in areas that do not currently have burn bans in place.

- Strong winds will continue to result in hazardous conditions for small craft across most coastal waters of southeast Louisiana and Mississippi. Additional periods of strong winds could lead to the extension of small craft advisories later in the week.

Short Term

(Now through Thursday night) Issued at 1215 PM CDT Mon Oct 26 2026

Deep layer ridging will continue to dominate the region through tonight and tomorrow. At the same time, a broad area of low pressure centered over Greater Antilles and Bahamas will persist. This will result in continued east-northeast flow in the low levels, and this will hamper any form of low level moisture return into the area. PWATS will remain below average and cloud development will limited to only some passing high level cirrus and scattered fair weather cumulus. The large diurnal range in temperatures of 25 to 30 degrees due to the largely clear skies and very dry air will also continue. Lows will dip back into the low to mid 50s inland the upper 50s and lower 60s south of the lake and along the immediate coast. Highs will quickly rise into the upper 70s and lower 80s each afternoon. The dry airmass continues to be best reflected by the NBM 5th percentile values, and this is what is being used for the dewpoints through tomorrow.

Heading into Wednesday and Thursday the ridge axis will shift to the east toward Florida and the southeast states and a weak shortwave trough will slide around the periphery of the ridge and through the Lower Mississippi Valley during this time. However, continued east- northeast flow in the low levels will greatly limit any Gulf moisture return into the region. This will result in continued dry weather conditions across the area with nothing more than some passing high cloud cover expected each day. Given the continued high bias of the deterministic NBM output, have opted to continue using NBM 10th percentile values for dewpoints on Wednesday and Thursday.

Long Term

(Friday through Sunday night) Issued at 1215 PM CDT Mon Oct 26 2026

Conditions are looking a bit more favorable for our first decent chance of rain in a while as we move into the Halloween weekend. A vigorous southern stream shortwave trough axis will begin to eject out of the Four Corners region Friday. This system will slide through the Lower Mississippi Valley on Saturday before quickly shifting toward the eastern seaboard on Sunday. Favorable jet dynamics over the southern Plains will allow a weak area of low pressure to form along a nascent front on Friday. As the low deepens Friday into Friday night, low level winds will shift to the southeast and allow for Gulf moisture to feed back into the forecast area. PWATS will quickly climb to around 1.7 to 1.8 inches, or near the 90th percentile, by Friday afternoon and will then continue to rise to around 2 inches for Saturday. Weak upper level support and a mid-level cap will keep any rainfall at bay on Friday, but more favorable lift and the deeper moisture in place on Saturday will support the development of scattered showers. These showers should persist into Saturday night before increasing negative vorticity and dry air advection takes hold in the wake of the departing trough on Sunday leading to drier conditions. Fortunately, thunderstorm chances will be near zero over the weekend due to weak mid- level lapse rates greatly limiting overall instability. Beneficial rainfall of around a half to three quarters of an inch is currently expected with these showers on Saturday. The increased moisture and cloud cover will also keeps low temperatures a bit warmer in the 60s for each night while highs remain near or slightly above average in the low 80s.

Aviation

(18Z TAFS) Issued at 1215 PM CDT Mon Oct 26 2026

High level cirrus will continue to stream across the region, but this will have no impact on aviation operations at area terminals. Winds will also remain easterly through the period. Overall, VFR conditions will be the rule through tomorrow.