textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 617 AM CDT Tue Mar 17 2026

- A Freeze Warning is in effect for locations along and north of the I-10/12 corridor tonight. Another light freeze may impact portions of the Northshore and coastal Mississippi Tuesday night.

- Warmer than average temperatures will return by the end of the week.

SHORT TERM

(Today through Wednesday) Issued at 156 AM CDT Tue Mar 17 2026

A very strong and deep longwave trough will continue to dominate the eastern half of the CONUS through Wednesday. This will keep northwest flow in place through the period. Cold and dry air will continue to advect into the region over this period, and this will keep skies clear, humidity values low, and temperatures well below average for mid-March. Temperatures tonight will fall below freezing for the northern half of the CWA and a freeze warning is in effect for these areas given the recent warm temperatures and greening up of plants that has been observed. South of I-10, lows will dip into the mid to upper 30s and wind chills will cool into the 20s and lower 30s. A reinforcing shortwave trough and associated dry front embedded within the broader northwest flow will slide through on Tuesday, and this will help the thermal trough axis in place. Highs will once again only climb into the mid 50s. Lows tomorrow night will cool into the 30s over inland areas and the 40s south of Lake Pontchartrain and along the Mississippi coast, but most areas will remain above freezing. Only the Pearl and Pascagoula River drainages are expected to dip back below freezing for a couple of hours Tuesday night due to cold air drainage down the valleys. Wednesday will see a modification of the temperatures as the heart of the thermal trough axis shifts to the east. However, highs will still be a good 10 degrees below normal in the 60s.

LONG TERM

(Wednesday night through Monday) Issued at 156 AM CDT Tue Mar 17 2026

Deep layer north-northwest flow will remain in place over the Gulf South through the upcoming weekend. This will be due to a strong longwave trough remaining in place across the eastern seaboard and a broad and strong upper level ridge remaining centered over the Rockies. This north-northwest flow pattern will result in a highly subisdent pattern in the mid and upper levels that will effectively keep conditions very dry across the area through the entire long term period. This will be a due to a strong mid-level capping inversion remaining in place as temperatures gradually warm through the period.

In the low levels, a broad surface high will be centered directly over the region. The wind field will remain very light, but a weak onshore component will form on Thursday and remain in place through Sunday. This will allow for higher dewpoints and overall humidity to feed back into the area by the weekend, but the aforementioned capping inversion will limit cloud development to only fair weather cumulus each afternoon. Temperatures will modify fairly quickly with highs rising from the 70s on Thursday into the low to mid 80s from Friday onward. Lows will also increase as dewpoints rise on the back of the persisent onshore flow. Readings will rise from the 40s on Thursday night into the 50s for Friday and Saturday nights. Overall, a very benign stretch of weather is expected in the long term period.

AVIATION

(12Z TAFS) Issued at 617 AM CDT Tue Mar 17 2026

VFR this cycle.

MARINE

Issued at 156 AM CDT Tue Mar 17 2026

Small craft advisory conditions will persist through tonight. Further easing of the winds will occur on Tuesday as high pressure becomes more centered over the waters. As the high shift eastward on Wednesday, winds will turn more easterly and fall to 10 knots or less. Seas will also ease to 3 feet or less by Wednesday morning. Winds will shift to a more southerly component on Thursday and remain very light. These more benign conditions will linger through the end of the week.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Freeze Warning until 9 AM CDT this morning for LAZ034>037-039- 046>048-056-057-071-076-079>086.

GM...Small Craft Advisory until 7 AM CDT this morning for GMZ530-532- 534-536-538-550-552-555-557-570-572-575-577.

MS...Freeze Warning until 9 AM CDT this morning for MSZ068>071-077- 083>088.

GM...Small Craft Advisory until 7 AM CDT this morning for GMZ532-534- 536-538-550-552-555-557-570-572-575-577.