textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 522 PM CST Sun Jan 18 2026

- A Freeze Warning is in effect for portions of the River Parishes and the Bayou region around Houma and Thibodaux for tonight as temperatures fall below freezing.

- Portions of the area along/north of I-12 in LA as well as the MS coast could see sub freezing overnight lows for 3 consecutive mornings, through Tuesday morning.

SHORT TERM

(This evening through Tuesday night) Issued at 1204 PM CST Sun Jan 18 2026

Through Tuesday, a very dry, cold, and stable weather pattern will be in place across the region as deep layer northwest flow persists on the southwest periphery of a strong longwave trough dominating the eastern half of the CONUS. Temperatures will remain well below average as a reinforcing front embedded within the deeper northwest flow pattern slips through the region Monday night. Due to the lack of return flow, moisture will remain extremely limited and skies will remain clear through Tuesday morning. This will allow for strong radiational cooling to take place both tonight and tomorrow night, and have opted to use the slightly cooler NBM 50th percentile output for the overnight lows. This results in low temperatures falling to between 30 and 32 degrees in the River Parishes and Bayou Region, and a freeze warning is now in effect for these areas tonight. Further to the north, temperatures will be right at the borderline for a cold weather advisory issuance, but have opted to not issue one for tonight as widespread 25 degree or lower temperatures are not expected. A few pockets in the Pearl and Pascagoula River valleys may fall to 24 or 25 for a couple of hours, but expect most areas to remain in the 26 to 28 degree range overnight.

Some moderation in temperatures is expected tomorrow night as the heart of the 925mb thermal trough axis shifts to the east along with the main longwave trough axis. However, lows will still fall below freezing along and north of the I-10/12 corridor for another night. Highs will also remain chilly with readings only climbing into the mid to upper 50s each day even beneath sunny skies. A more significant warming will take place Tuesday night as a surface high begins to shift to the east and winds turn more easterly and southeasterly through the night. Moisture will gradually return, especially in the upper levels, and a cirrus deck aloft will limit the amount of radiational cooling that occurs. As a result, lows will remain above freezing, but will still be chilly with readings ranging from the mid 30s in southern Mississippi to the mid 40s along the Louisiana coast.

LONG TERM

(Wednesday through Saturday night) Issued at 1204 PM CST Sun Jan 18 2026

A return to a rainier weather pattern will take hold on Wednesday and continue through the end of the week as a series of fast moving and weak shortwave troughs slides through the area. These shortwave troughs will be embedded within a more zonal flow pattern aloft that develops in the wake of the trough currently dominating the eastern half of the CONUS finally lifting out to the northeast. The first of these fast moving features will have a favorable jet couplet pass over the Lower Mississippi Valley Wednesday night into Thursday. This couplet will support stronger deep layer forcing across the region. At the same time, increasing onshore flow over the area will continue to feed into deeper low and mid- level moisture values, and PWATS will rise to over an inch by Wednesday night. The end result will be overcast skies and periods of light to moderate rainfall impacting the entire forecast area. Rain chances will be highest Wednesday night when forcing is greatest, but light rain showers should begin to develop over the western half of the CWA by Wednesday afternoon. As the jet couplet and shortwave trough quickly pulls to the east Thursday afternoon and evening, the rain will also shift out of the area with a dry forecast in place by Thursday night. Temperatures will also continue to warm as the onshore flow persists with highs closer to average in the lower 60s and lows only cooling into the 40s.

A brief window of drier weather will take hold Thursday night into Friday as increasing negative vorticity advection and upper level subsidence develops in the wake of the departing shortwave trough. Temperatures will warm and humidity will fall in the mid and upper levels as a weak shortwave ridge moves over the area. This brief respite in the rain will come to end by Friday night as another southern stream shortwave trough begins to approach the region. As the trough deepens to the west of the area, a broad region of increasing positive vorticity advection and lift will overspread the forecast area Saturday into Saturday night. Moisture will also deepen again with PWATS climbing back above an inch. This combination of moisture and lift will support scattered light rain shower development over this period and the forecast reflects this with PoP of 30 to 40 percent in place. Continued onshore flow and the more zonal flow pattern aloft will allow temperatures to continue to warm with readings rising into the lower 70s by Saturday. Overall, have opted to stick with the NBM deterministic output in the extended period as there are still large temperature spreads between the various models. This is due to temporal and spatial differences in the positioning of the trough to the west on Saturday.

AVIATION

(00Z TAFS) Issued at 522 PM CST Sun Jan 18 2026

VFR conditions through the forecast period. Little or no cloud cover expected.

MARINE

Issued at 1204 PM CST Sun Jan 18 2026

Winds have started to fall off over the past few hours over the waters and the small craft advisory was allowed to expire at Noon. These lighter offshore winds of 10 to 15 mph will persist through tomorrow night as a broad area of high pressure remains centered to the northwest of the waters. A reinforcing front will slip through late tomorrow night, and winds may briefly rise to exercise caution range of 15 to 20 knots Tuesday into Tuesday night. However, the high will shift to the east on Wednesday as a weak low pressure system moves in from the west. Winds will shift to the east and southeast Wednesday into Wednesday night, but a shift back to the northeast for Thursday is expected in the wake of the passing storm system. Winds will increase back to 15 to 20 knots Thursday into Thursday night due to the increased pressure gradient over the Gulf from this low and a high to the west. The wind field will once again relax on Friday to 10 to 15 knots and allow a wind shift to the east and southeast as the low departs to the east and a broad area of high pressure takes hold of the eastern Gulf.

PRELIMINARY POINT TEMPS/POPS

MCB 26 56 28 55 / 0 0 0 0 BTR 27 59 30 57 / 0 0 0 0 ASD 24 57 27 57 / 0 0 0 0 MSY 33 56 37 56 / 0 0 0 0 GPT 28 57 30 57 / 0 0 0 0 PQL 24 57 26 57 / 0 0 0 0

LIX WATCHES/WARNINGS/ADVISORIES

LA...Freeze Warning from midnight tonight to 9 AM CST Monday for LAZ056>060-065>067.

GM...None. MS...None. GM...None.