textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 104 PM CDT Tue Mar 17 2026

- A Freeze Warning is in effect again for tonight. This is for areas mainly along and north/east of a line from McComb to Slidell to Pascagoula. Lows could drop to as low as 29/30 and most locations should only be at or slightly below freezing for 1-3 hours.

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

SHORT TERM

(This evening through Wednesday night) Issued at 104 PM CDT Tue Mar 17 2026

It was a quiet and cool night last night but lows didn't quite drop as much as expected. This was likely due to still having some wind out there as KHDC VWP showed winds still at or above 20 kts at the first gate through the night and up until sunrise. This likely provided enough mixing to have an impact on radiational cooling overnight but as high pressure finally settles in that won't be the case tonight. We still had a light freeze in many areas but lows were just a tad warmer than forecast. As for today, it has been quite the nice one with the only real thing needed was slightly warmer temps this afternoon given temps in the upper 40s to mid 50s by 18z.

The next 36 hours will be benign with the only real impact being another light freeze for northeastern sections of the CWA. Synoptically the CONUS is being dominated by a L/W over the eastern half and a large ridge over the western CONUS. This has placed the Lower MS Valley under northwest flow aloft. At the surface large area of high pressure is centered over the western and northwestern Gulf Coast and stretches north through the MS Valley into the far western Great Lakes region. Otherwise no other major surface system is centered over the CONUS outside of a broad area of high pressure west of the Continental Divide. There are two areas of low pressure centered in Canada. One is east of the Hudson Bay while a weaker broad area of low pressure is centered over along the Saskatchewan and Alberta provinces border. As that surface high over the coast continues to settle in winds have relaxed significantly and that along with the northwest flow aloft is leading to our rather nice, cool, dry, and generally sunny skies.

As for tonight. With offshore flow still we are not seeing any moisture return yet and LL temps are not quite moderating yet either. This is keeping us well below normal for highs today and this could set the stage for another chilly night especially the northeastern 3rd of the CWA. Clear to mostly clear skies will remain in place all night and the surface high will slowly work northeast becoming centered over the southern Appalachians late tonight. We will still see high pressure wedge southwest across most of the area tonight allow winds to decouple if not becoming completely calm quickly this evening. So we will have a rather decent starting point this evening with highs well below normal, high pressure leading to winds being light if not calm, and no real cloud cover to worry about (not even cirrus). The rain wasn't that heavy Sunday night and with the winds yesterday, a lot of sun, and dry air there likely isn't any residual ground moisture that would hurt radiational cooling tonight. As for the dry air that was just mentioned, dewpoints this afternoon have plummeted across the region dropping into the low teens to near 20 for most of the area, MCB has dropped all the way down to 8. So this all suggests a very favorable radiational cooling setup and honestly historically the second night after a cold front is the better Rad cooling night and then combine that with the sfc high centered to our northeast yet wedging southwest through the area into the Gulf and the feeling here is that we could see some areas getting colder tonight than last night, especially the drainage areas around the Pearl and Pascagoula Rivers. With that the thinking is the NBM is too warm and looking at the latest MOS guidance, they are running around 2 to 4 degrees cooler. With that we used a blend of 1 part NBM 2 parts NBM25 for all of the area and then used a 1:4 across the drainage areas across our northeast. This is providing a low of near 30 around PQL, BXA, and ASD and then upper 30s to near 40 across the Southshore. With that we did issue another Freeze Warning for the far northeast for tonight.

As for tomorrow and tomorrow night, the benign forecast continues. We remain under northwest flow aloft and may even see a weak impulse slide across the region but with the very dry airmass in place this will provide nothing more than some mid to upper lvl clouds. We will see some moderation with h925 temps climbing to around 7-9C. That would suggest highs in the lower to mid 60s however NBM is advertising some western areas approaching 70. That seems a little overzealous but not confident enough to lower the highs any. All MOS guidance is suggesting highs ranging from the near 60 to mid 60s. High pressure does continue to drift northeast but it will still dominate the region leading to rather light winds and no significant moisture return which should provide one more cool night before we return closer to normal. /CAB/

LONG TERM

(Thursday through Monday night) Issued at 104 PM CDT Tue Mar 17 2026

As for the extended portion of the forecast we remain rather quiet. Medium range models aren't suggesting any significant rain chances for practically the next 10 days. Given the rather decent agreement between the medium range models, their ensembles, and the NBM see no reason to deviate from the latest NBM guidance.

We start out the extended portion of the forecast under northwest flow still on Thursday and even as the ridge to the west gets suppressed and tries to nudge eastward across TX we will generally remain under northwest flow through the weekend. This will send another weak impulse or two across the region but with out any real moisture recovery still those impulses will likely be accompanied by nothing more than some increase in clouds. High pressure will dominate the region at the surface. Our surface high associated with our cold airmass will be sliding to the northeast away but we will see high pressure quickly rebuild across the north-central and northeastern Gulf Friday. As that high becomes centered over the eastern Gulf this weekend we will finally start to see some return flow. This will allow us to continue to moderate through the end of the work week and the weekend with high likely back in the upper 70s to lower 80s possibly even mid 80s.

Next week as we look to possible break out into more zonal flow and possible slightly better rain chances Mother Nature says otherwise with a ridge quickly rebuilding over the southwestern CONUS placing the area back under northwest flow. This put a hard stop on the moisture recovery in the mid lvls and thus hurt any rain potential the first half of next week. The southwest CONUS ridge will continue to build through the the first half of the week and start to slide east and likely wedging into the region which could lead to rather warm conditions late next week. /CAB/

AVIATION

(18Z TAFS) Issued at 1258 PM CDT Tue Mar 17 2026

No issues on the aviation side. VFR conditions are anticipated through the entire forecast. /CAB/

MARINE

Issued at 104 PM CDT Tue Mar 17 2026

High pressure continues to settle in over the area with winds relaxing. This high pressure will slowly work to the northeast leading to generally light and variable winds especially near shore winds with light easterly winds over the outer water late tomorrow and Wednesday night. Thursday we will see high pressure start to settle back down into the north-central and northeastern Gulf before it finally becomes situated over the eastern Gulf this weekend. This will continue to lead to light and variable winds Thursday and then a slow but steady turn to southerly and southwesterly winds (onshore flow) this weekend. The light winds will lead to low waves/seas 2-3 ft or less through the forecast. /CAB/

LIX WATCHES/WARNINGS/ADVISORIES

LA...Freeze Warning from 1 AM to 8 AM CDT Wednesday for LAZ039-079.

GM...None. MS...Freeze Warning from 1 AM to 8 AM CDT Wednesday for MSZ070-071- 077-083>085.

GM...None.