textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1208 AM CST Mon Dec 15 2025 - The coldest air of the year will bring dangerous wind chills and a widespread freeze to the area tonight into Monday morning. A Cold Weather Advisory is in effect over this time period.

- Strong winds and dangerous seas are expected into Monday after a strong cold front moves through. Small Craft Advisories and Gale Warnings are now in effect for this time period.

SHORT TERM

(Today through Tuesday) Issued at 1208 AM CST Mon Dec 15 2025

Clear and cold out there. Temperatures haven't cooled off as fast as expected and this likely has a lot to do with the wind. Even at 5z winds KHDC VWP continued to shows winds of 25 to even 30kts at the 1st and 2nd gates. Even with winds of 7-9kts in the boundary layer those winds only 1-2k ft abv the sfc will help to mix things keeping the region from dropping as fast. However, dewpoints have absolutely plummeted to the mid teens along and north of the 10/12 corridor while falling into the upper teens to mid 20s across areas of SELA along and south of I-10. So what does that mean, well if winds can relax some more and perhaps get below 15kt at 1k ft for just a few hours this morning temps will likely plunge for that short time. If winds can't back off enough in the LL we will be a few degrees warmer than forecast.

As for today through Tuesday, quiet and cold start with quickly moderating conditions tomorrow. As mentioned last night the biggest problem with this forecast is how shallow this cold airmass is. It is even below h925 which could easily be seen on this evenings sounding. With that, it makes the forecast difficult with respect to highs today. H925 temps will be around 4-7C today but we will likely not mix up to h925 and thus a mix down temperature from that level would result in mid 50s to lower 60s which would be too warm. MOS and NBM all suggest much cooler and fcst sndgs show us not mixing the h925 so highs in the upper 40s to near 50 seems fair.

Tonight not as cold as it will be this morning but it will be another cold one. High pressure will be firmly in control and skies should remain clear. This will provide a rather favorable radiational cooling set up but with the airmass already beginning to moderate some we are looking at a light to moderate freeze over the northern half of the CWA. No headlines will be issued at this time but we may need a targeted Freeze warning for some of the River Parishes. Areas like Ascension, Assumption, St James, Upper Terrebonne and Lafourche, and perhaps portions of St John may drop down below freezing for a few hours which may necessitate a freeze warning. Areas along and north of the 10/12 corridor typically don't see another freeze warning after the first 2 freezes of the season or if we go a prolonged period (like a month of two) of well above normal temps and vegetation that was dormant has begun growing again.

Tuesday the modification will be well underway. S/W ridging will already be moving across the region tonight and we will have the ridge sitting directly on top of the area Tuesday. At the sfc by midday Tuesday high pressure will be centered well west of the area and return flow will quickly start to set up. We will see both temps and moisture quickly moderate with highs climbing into the upper 50s to lower 60s, maybe even a touch warmer. /CAB/

LONG TERM

(Tuesday night through Sunday) Issued at 1208 AM CST Mon Dec 15 2025

Heading into the extended portion of the forecast nothing of any significance from impacts but we will see another system move through the region late this week which will bring some light rain into the area and a quick shot of slightly cooler and drier air. The trend from the Global models has been to drive the disturbance currently over CA southeast and digging into Mexico with the next cold front and rain Thursday and the latest NBM is pretty much on target with that. See no reason to make any major deviations from the latest NBM.

Current WV shows the next disturbance rather well over CA and as slightly stronger mid lvl winds dive into the back side of it tonight and Tuesday it will begin to dive more southeast over the Baja and into western Mexico. The ridging that moves over the area tonight and tuesday will help to block its eastward progression which will also lead it to diving and deepen over Mexico Tuesday. This will lead to troughing across the southern Plains and southwest into central and western Mexico. A piece of the disturbance though will continue to work east across the southern plains with a subtle piece of energy possibly moving across the lower MS Valley Wednesday. This appears to help draw moisture back to the north quickly as it surges north across the western Gulf and into the area Wednesday with PWs climbing back to around and just under 1.5" Wednesday night. There may even be a few very light showers/sprinkles with the passage of this impulse but likely mostly virga. However this will be right ahead of a much stronger disturbance in the northern stream dropping into the central CONUS Wednesday night and Thursday. This system will help the L/W trough dig across the MS Valley and eastern CONUS Thursday and Thursday night and drive a Pacific cold front across the region late Thursday/Thursday night. We will see some rain with this system Thursday and Thursday evening and then drier and slightly cooler air back into the area Friday and Saturday before we quickly warm back up again. /CAB/

AVIATION

(06Z TAFS) Issued at 1208 AM CST Mon Dec 15 2025

VFR conditions are over all terminals and will continue. LLWS may be the only concern over a few termninals from now through 13z but with winds expected to slowly relax this should not be a concern. /CAB/

MARINE

Issued at 1208 AM CST Mon Dec 15 2025

Strong winds continue across the waters with high end SCY conditions in the sounds and inner waters with the outer waters still seeing gusts in Gale. Winds will begin to subside during the early morning hours and then quickly subside after sunrise. Another high will then quickly settle over the area on Tuesday, and this will allow winds to turn more easterly and fall back to less than 10 knots. Seas will also begin to subside as the winds decrease Monday night into Tuesday. These lighter winds and calmer seas will persist through Wednesday. As the sfc high slides east and the next front approaches the Lower MS Valley winds will begin to turn more onshore out of the southeast, winds will also increase and headlines may be needed overnight Wednesday night through Thursday night. /CAB/

PRELIMINARY POINT TEMPS/POPS

MCB 47 26 58 42 / 0 0 0 0 BTR 49 29 60 44 / 0 0 0 0 ASD 49 27 61 43 / 0 0 0 0 MSY 48 38 62 50 / 0 0 0 0 GPT 49 33 59 47 / 0 0 0 0 PQL 49 26 60 42 / 0 0 0 0

LIX WATCHES/WARNINGS/ADVISORIES

LA...Cold Weather Advisory until 9 AM CST this morning for LAZ034>037- 039-046>048-056>060-064>071-076>090.

GM...Small Craft Advisory until 9 AM CST this morning for GMZ530-532- 534-536-538-550-552-555-557.

Gale Warning until 9 AM CST this morning for GMZ570-572-575-577.

MS...Cold Weather Advisory until 9 AM CST this morning for MSZ068>071- 077-083>088.

GM...Small Craft Advisory until 9 AM CST this morning for GMZ532-534- 536-538-550-552-555-557.

Gale Warning until 9 AM CST this morning for GMZ572-575-577.