textproduct: New Orleans/Baton Rouge

SHORT TERM

(Today through Friday) Issued at 224 AM CST Thu Dec 26 2024

Most of the rainfall/convection from earlier has pushed off to the east leaving most of the area mostly rain free (outside of a few pockets of drizzle here and there). That said, what has started to occur for much of the CWFA is fog development. At this juncture, guidance and traffic cameras along with surface obs have shown a good bit of development across the CWFA over the last couple of hours. Unless the low level flow increases over the next hour allowing the fog to become more of a low stratus situation, will likely issue a dense fog advisory, especially with continued holiday travel and AM commute just a few hours away.

Today will largely be dry across the region. We will start to eye the next feature upstream later this afternoon and into the evening hours. Models are showing what appears to be a thin line of showers and thunderstorms. Low level shear is favorable for an isolated severe storm or two, however, instability will be lacking as the feature arrives in our neck of the woods late tonight or perhaps even early Friday. Also, another limiting factor is the limited upper support with most of the support residing to our west and north as the upper level shortwave ejects north, away from our area later tonight. The main threat with this activity will be wind. However, as H5 temperatures fall back to around -12/-14C respectively, hail potential cannot be ignored in the wider strong updrafts. There is a surface cold front residing across southeast Texas. At this point, the front should remain well within the active southwesterly flow and shouldn't really move much, however, if deeper convection fires across southeast Texas, there could be a stronger cold pull push which could allow the front to move a bit closer than current thinking.

Outside of perhaps a few lingering showers along the surface boundary, mostly across our western tier, we again largely look dry. Once again tonight and early Friday may have some fog development with the signal a bit stronger than this morning. Will hold off on a dense fog adv and let the day shift take another look. Otherwise, temperatures are mild and well above average. (Frye)

LONG TERM

(Friday night through Wednesday) Issued at 224 AM CST Thu Dec 26 2024

Going into the last weekend of the year, eyes again shift upstream as yet another H5 shortwave begins to move eastward Saturday afternoon. Showers and perhaps a rumble of thunder can be expected from around midday on. As the upper level impulse continues down stream over the MO Ozarks and into the mid MS River Valley in the afternoon and overnight, the surface front will finally start to clear the region from west to east. POPs will be there Sunday morning, however, this should quickly shutdown as low level flow turns more northerly and cooler and drier air begin to settle back into the region on Sunday. Beyond this, globals tend to agree with the overall progressive zonal flow that sets up across the region. No big cool downs (at least for now) so near or above average temperatures and perhaps a slight uptick in rain chances on Tuesday. (Frye)

AVIATION

(06Z TAFS) Issued at 1126 PM CST Wed Dec 25 2024

In the near term, concerns will be with low ceilings and/or visibilities, with most terminals already reporting IFR ceilings. KHUM currently near field minima, with traffic cams around the Houma area showing patches of fog as well. Main question is whether boundary layer winds will mix enough to keep a low stratus deck in, rather than dense fog. Expect IFR or lower conditions through mid to late morning at most or all terminals, with at least some threat of conditions at field minima. Even if fog doesn't occur, don't anticipate conditions improving to even MVFR until 16z or so.

Second concern will be the potential for TSRA toward the very end of the forecast period. Some convection allowing models are showing potential for a line of TSRA over western Louisiana in the 00z-06z Friday time frame, with storms weakening as they approach our western terminals around 06z. If storms hold together longer than expected, the 12z TAF package will need to address that for at least KBTR and KHUM.

MARINE

Issued at 224 AM CST Thu Dec 26 2024

Moderate onshore return flow will continue into the upcoming weekend. Short fused SCAs are possible for the outer Gulf Waters, especially. A weak front will move through the region early Sunday, which should help transition to a more offshore or northerly flow. At this juncture, winds and seas are not forecast to go into SCA ranges. (Frye)

PRELIMINARY POINT TEMPS/POPS

MCB 67 60 73 60 / 30 70 80 60 BTR 75 65 78 62 / 30 60 70 60 ASD 71 61 76 61 / 20 40 60 50 MSY 72 63 77 63 / 20 30 60 50 GPT 67 61 71 60 / 20 40 60 60 PQL 71 60 77 62 / 20 30 60 60

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Dense Fog Advisory until 10 AM CST this morning for GMZ530-534.

MS...None. GM...Dense Fog Advisory until 10 AM CST this morning for GMZ534.