With ridging sitting over the area for the better part of September, all of southeast Louisiana and southern Mississippi saw significantly less rainfall than usual for September. This lead to continuation of drought conditions during the whole month of September.
Every event with a place to put it; 11 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LIX wrote it up.
With ridging sitting over the area for the better part of September, all of southeast Louisiana and southern Mississippi saw significantly less rainfall than usual for September. This lead to continuation of drought conditions during the whole month of September.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS New Orleans, LA wrote its last area forecast discussion before the first event at Aug 31, 10:49 PM CST, 1 hour 11 minutes earlier.
Area Forecast Discussion National Weather Service New Orleans LA 1149 PM CDT Thu Aug 31 2023 ...New AVIATION... .SHORT TERM... (This evening through Friday night) Issued at 232 PM CDT Thu Aug 31 2023 Starting out with this afternoon/evening, not a bad day at all out there! Kept the same modifications in the morning update rolling, with a slight uptick in forecast highs nudging towards a blend of the 50th/75th percentile and adjustment utilizing the 10th percentile for dewpoints which has matched with obs well so far. Big story in the short term begins with tonight, as recent GOES-16 satellite derived PW and surface obs indicate, a rather noticeable moisture gradient situated across half of the CWA, bordering much drier, mixed air along/north of I-10/12 as dewpoints have gotten into the lower 60's/upper 50's and area- averaged PW ~1.1-1.3", to much deeper Gulf moisture bleeding inland across coastal SE LA with dewpoints in the 70's and area- averaged PW's in the 1.9-2.1" range. Deeper low/mid-level tropospheric moisture continues to build north overnight tonight, owing to mostly cloudy skies. This is in response to strengthening southerly flow aloft, generally between H7 to H3 out ahead of a cut-off piece of energy to our west, which steadily deepens and accelerates southerly flow in conjunction with downstream dynamic ascent. All signs confidently point to our typical warmer shelf water marine convection early Friday becoming much more widespread given aforementioned reasonings for enhanced coverage, but also supporting strong/severe storm potential (>34kt wind gusts and waterspout potential) beginning in the 2-5AM time frame, and persisting thru the mid/late morning hours. Upper-level flow being progressive and relatively strong out the of south will support anvil spread/blowoff north across land areas of the CWA. Add to that the deeper mid-level moisture source and low/mid- level cloud cover means we'll likely remain mostly cloudy to start the day, if not completely overcast for some. Will have to monitor for how much clouds stay lingering in place, potentially offsetting the typical diurnal destabilization to perhaps later in the day. But if not and we see a bit more sunshine in the morning, we'll take no time to see scattered convection across land areas, with better coverage along/south of I-10/12 within overall deeper tropospheric moisture and associated instability. Not anticipating strong to severe storms over land, but will continue to message tropical funnel cloud/waterspout risks from storms anchored to any outflow boundary activity. Some gusty winds, but not seeing a definitive well- mixed PBL coupled with any low-level dry air entrainment to support a concern other than occasional 30-40mph gusts in locally stronger storms. Additionally, given plenty of reasonings for greater convective coverage near/along coastal areas, decided to lower highs in this region, with a nudge back to 25th percentile elsewhere. Dropped temps more along the coast than anywhere else, where confidence for greater coverage and attendant cloud cover should keep temperatures several degrees cooler than we saw today (generally upper 80's to lower 90's) but the tropical, humid feel to the air we are all too familiar with will be back making it feel muggy. The lack of hot afternoon temperatures will thankfully make it more bearable than last week(s) so there's some positivity. Also, we can take the rain as we are in a widespread D3 drought per latest drought monitor released earlier today. So, we'll take what we can get. Any showers/storms that developed over land areas will come to an end following decoupling around sunset, with partly/mostly cloudy skies persisting thru the overnight. && .LONG TERM... (Saturday through Wednesday night) Issued at 232 PM CDT Thu Aug 31 2023 A weak wave of low pressure is being felt as it moves west along the central gulf coast and then moves into east Texas, getting incorporated into synoptic flows by midweek. Those synoptic flows are characterized by a strong upper level low starting over the Pacific Northwest which moves east as a trough. The trough is broken down by high pressure over the south and southwest as the week progresses. The best news in the forecast is that the weekend into early next week has rain chances associated with that low. Even during the mid-week high pressure, there will still be some chances for summertime afternoon convection at least closer to the coast. Toward the end of the week, a trough rebuilds over the south as high pressure pulls back to the west bringing increased chances of rain. Temperatures over the weekend are expected to be above normal but are moderated by the moisture in the atmosphere and rainfall. Even though there is high pressure in the outlook, temperatures are not extreme with highs in the mid to upper 90s and apparent temps in the low 100s. With these numbers there shouldn't be a need for any excessive heat headlines. Unfortunately, the extended period beyond this forecast package see above normal temperatures and quite possibly a return of excessive heat. Along with this is a below normal outlook for rainfall, so the drought continues. Stay tuned for details. /Schlotz/ && .AVIATION... (06Z TAFS) Issued at 1141 PM CDT Thu Aug 31 2023 Expect VFR conditions to prevail through the night tonight. High resolution models are depicting scattered convection developing in the early afternoon timeframe in response to the upper-level low over the area. Wanted to do focused TEMPO groups, but given the nature of the storms are scattered, confidence is low on exactly when or where each cell is going to pop up, so only VCTS wording was mentioned at all sites except for BTR starting from the early afternoon and lasting until the evening around 7-10 pm. After that, expect a return to VFR conditions overnight. && .MARINE... Issued at 232 PM CDT Thu Aug 31 2023 Daily widespread scattered showers and storms can be expected each morning beginning on Friday, lasting thru the weekend and into the day on Monday. Storms may be locally strong to severe with wind gusts >34kts, waterspouts and locally enhanced waves/seas the main risks. High pressure builds into the region Tuesday thru late- week, with rain chances lowering some, but activity remains possible over warmer shelf waters mainly each morning. Outside of thunderstorm activity, waves will be mostly calm with only occasionally breezy winds at times. && .PRELIMINARY POINT TEMPS/POPS... MCB 97 69 93 72 / 0 0 40 40 BTR 99 73 96 76 / 0 0 40 30 ASD 96 73 91 75 / 10 20 70 70 MSY 95 79 90 79 / 10 20 70 70 GPT 95 76 88 75 / 10 30 80 90 PQL 96 73 89 73 / 10 40 80 90 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && SHORT TERM...KLG LONG TERM....DS AVIATION...JZ MARINE...KLG
The national radar mosaic for the moment the first event began.
11 drought. Local standard time, as filed.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
Portions of the zone was under D2 to D4 drought due to minimal rainfall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Mississippi in 2023Every state in 2023This day in weather historyWarnings in Mississippi, September 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1142886, 1142887, 1142888, 1142889, 1142890, 1142891, 1142892, 1142893, 1142894, 1142895, 1142896.