628 FXUS64 KLIX 062337 AFDLIXArea Forecast Discussion National Weather Service New Orleans LA 637 PM CDT Sat Sep 6 2025
...New AVIATION...
.SHORT TERM... (This afternoon through Sunday Night) Issued at 1116 AM CDT Sat Sep 6 2025
Few items to discuss right off the bat early this Saturday afternoon. The long-waited front has drifted into the area, with GOES-16 Ch2 VIS trends and KHDC radar illustrating where the front is generally located approaching the I-10/12 corridor. For now, what is left of this boundary following scattered showers earlier over far NW areas is just a cloud line, representing primarily a air density difference without a well-defined wind shift. This boundary is separating post-frontal/subsident and drier air behind it with a well-developed Cu field ahead of the front within slightly deeper available moisture. Ahead of this moisture boundary (front) shows noticeably lower Tc per 12Z HRRR proximity soundings indicating enough diurnal destabilization coupled with weak frontogenetic lift will support scattered showers/storms mainly over the I-10/12 corridor on south. 13Z NBM brought in some plausible numbers ranging in the 15-25% range, with no changes needed here. Not seeing anything stand out significantly with the tropospheric thermal profile representing any threat for locally strong to severe storms with this activity later today, but a few could become locally strong and dump brief heavy rainfall. All activity diminishes after the front sweeps SE and we lose the diurnal support tonight, revealing a quiet night as dry air continues to progressively pump into the region from the north. Sunday is looking rather nice with some low/mid-level stratocu/altostratus around. No adjustments needed to temperatures as all guidance is coming in looking in line with thoughts. KLG
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.LONG TERM... (Monday through Friday) Issued at 1116 AM CDT Sat Sep 6 2025
By Monday and into Tuesday, the main story is another reinforcing shot of the drier/cooler air builds into the region. Took a very close look at two items here: Min temperatures Monday and Tuesday morning and dewpoints Monday and Tuesday afternoon. For lows, deterministic 13Z NBM is coming in already on the low side of the ensemble spread, generally in the 25th-10th percentile so did not adjust suggested lows much in this case, other than massaging traditionally cooler locations across the Pascagoula and Pearl River drainage basins. Next, did apply a noticeable target of opportunity to dewpoints both Monday and Tuesday afternoons during peak diurnal mixing, as model soundings illustrate a well-mixed PBL/adiabatic thermal profile to 1) support occasionally breezy winds and 2) likely mix down well below suggested deterministic NBM guidance. Introduced a steady transition to 25th to eventual 10th percentile dewpoints both afternoons, bringing MinRH`s into the 30`s for most areas. This will without a doubt make it feel much, much more comfortable both days. As mentioned yesterday, something to remember is the sun angle is still pretty high, and in the direct sunlight it`ll still feel hot (and a much drier atmosphere will likely spike UV index making for a risk for sunburn). Something to consider, otherwise it`ll be a nice change in the hot summer we`ve been through so far and a nice reminder that Fall is almost here! Beyond Tuesday into the middle to later parts of the week, moisture steadily returns back to the region underneath a building upper-level weakness (broad SE US troughing pattern) that`ll bring back a few scattered shower/storm chances. For now, best chances are looking across the coastal areas of SE LA and MS, within greatest total column moisture, but will monitor how far north moisture return builds to support shower activity within this upper-level weakness with time. Temperatures remain seasonal, with no excessive heat concerns over the next 5-7 days. KLG
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.AVIATION... (00Z TAFS) Issued at 631 PM CDT Sat Sep 6 2025
Drier air is being ushered in by light northerly flow behind a weak frontal system, and VFR conditions will prevail through the period. Only a slight chance for pop-up weak convection near HUM on Sunday which does not warrant a PROB30 at this time.
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.MARINE... Issued at 1116 AM CDT Sat Sep 6 2025
A cold front is expected to progress south across marine waters later this afternoon into tonight, introducing a steady wind shift from the NNE to NE and drier air to progressively filter into the region into the day on Sunday. Winds will be delayed to respond increasing primarily 12-18kts for Gulf waters during the morning thru afternoon hours on Sunday, with another reinforcing push of NE winds expected overnight into early Monday. During this time period (primarily 12AM thru 3PM Monday), winds may reach sustained upwards of 15-20 knots, especially for outer Gulf zones south of the MS sound including Chandeleur and Brenton sounds. Exercise caution headlines are expected, but could briefly touch Small Craft Advisory for portions of these areas during this time frame. Waves/seas will respond into the 3-5ft range generally. Mid/late week, winds shift more easterly but remain slightly elevated in the 10-15kt range, especially for eastern zones which will keep waves/seas also slightly elevated in the 2-4ft range for outer waters, 1-2ft for protected waters. KLG
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.PRELIMINARY POINT TEMPS/POPS... MCB 68 85 62 84 / 10 10 0 0 BTR 71 88 66 87 / 10 20 0 0 ASD 69 89 63 88 / 10 10 0 0 MSY 76 90 73 89 / 10 10 0 0 GPT 70 90 66 89 / 10 10 0 10 PQL 69 90 64 89 / 10 10 0 10
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.LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. &&
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SHORT TERM...KLG LONG TERM....KLG AVIATION...TJS MARINE...KLG
NWS LIX Office Area Forecast Discussion