A ongoing rainy pattern that had been in place for a week or more continued on August 9th. The seabreeze boundary on the south side of Lake Ponchartrain became the focus for thunderstorms to develop around the New Orleans Metro.
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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.
A ongoing rainy pattern that had been in place for a week or more continued on August 9th. The seabreeze boundary on the south side of Lake Ponchartrain became the focus for thunderstorms to develop around the New Orleans Metro. Due to the fact that these storms developed on the seabreeze, their movement was slow. This, combined with abundant moisture in place, resulted in flash flooding at a few locations in Jefferson Parish.
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 9, 10:26 AM CST, 2 hours 34 minutes earlier.
Area Forecast Discussion
National Weather Service New Orleans LA
1126 AM CDT Tue Aug 9 2022
...UPDATE...Overall the forecast is on track only made some minor
adjustments to speed up rain and increase PoPs based on trends.
Scattered storms are starting to develop across SELA as we heat up
but most of the will take places this afternoon as we start feel
the impact of the tropical wave just off our coast. Some of the
same areas that have seen heavy rain will likely see it again
today; those locations are around the New Orleans metro, portions
of the Northshore and coastal MS. Anywhere where storms have and
continue to develop and before outflow boundaries take over has
the best chance for longer periods of locally heavy rain. Also
areas between NO and Houma and BR where we could see numerous
boundaries collide; seabreeze, lake breeze, and differential
heating boundary on the east side of the Atchafalaya basin.
Looking at current satellite and radar there is definitely some
low level spin in the waters east of the MS delta and south and
coastal MS. This could provide a little more forcing than we would
like leading to stronger storms capable of producing very
efficient rain and possibly falling over the same areas. Main
areas of concern through the afternoon again appear to be that
line mentioned earlier and south of it. This does include the New
Orleans metro and coastal MS like Gulfport and Biloxi. /CAB/
&&
.AVIATION...18Z TAF Package...Convection is the greatest impact
through the afternoon and early evening. Some low cigs are
impacting terminals off and on leading to tempo MVFR cigs but
overall as long as these sites remain convection free they should
remain in VFR status. After convection winds down all terminals
will move back into VFR status if not already there but around
9/10z we could see the same issues we have been for the last few
days with IFR and possibly LIFR cigs along with patchy IFR vsbys.
the most likely time to see these impacts will be from 9-13z and
probably over the same locations like MCB and BTR. /CAB/
&&
.PREV DISCUSSION... /issued 422 AM CDT Tue Aug 9 2022/
SHORT TERM (Today through Thursday)...
In a near carbon copy of last week, rain chances will once again
continue to be high through the period. High pressure over the
western Atlantic will keep the area in a period of onshore flow.
In addition, a tropical wave will be moving slowly across the
north-central Gulf of Mexico today and tomorrow. The combination
of those features will allow tropical moisture to stream into the
area, supporting high precipitation chances and the possibility
that some of the showers and thunderstorms could be extremely
efficent rainfall producers. Steering currents are fairly weak as
well, increasing the possibility of heavy rainfall across the
area.
Much of the same is expected tomorrow and Thursday as the heavy
rain potential will only increase. Given the rather high rainfall
amounts over the past few weeks along with the expected rainfall
today and tomorrow, some additional concern is warranted for
tomorrow and Thursday. Deep moisture will still be entrenched
across the region allowing for areas of heavy rain once again.
Training bands of rain along with merging cells could bring hourly
rainfall rates as high as 3 inches. Due to this possibility, most
of the area has been outlooked for a slight risk for excessive
rainfall tomorrow and into Thursday morning and may need to be
expanded in time. A Flash Flood watch may be warranted later in
the week but opted to hold off for now to see the coverage and
amounts that occur today.
In addition to the rainfall concerns, a coastal flood advisory is
also in effect through midday Thursday due to the persistent
onshore flow. This is mainly for issues that may develop during
the normal high tide periods.
LONG TERM (Friday and beyond)...
No significant changes made to the long term portion of the
forecast. Persistent ridging over the central Rockies will slide
slightly east and south by the end of the week. This will place
our area on the eastern periphery bringing a period of northerly
flow into the area. Due to this, the focus for the shower and
thunderstorm activity over the weekend will shift from a heavy
rainfall threat to more strong storms with wind gust potential.
AVIATION...
Lowering ceilings and visibilities are currently causing LIFR
conditions at KBTR and KMCB and may do so at least periodically
throughout the rest of the overnight period until at least
sunrise. Cannot totally rule out development of SHRA/TSRA at
coastal terminals by 14-15Z, but greater threat gets going around
midday. For now, will use VCTS at all terminals, but as a focus
becomes more apparent will update with the best times for direct
impacts, as storm movement is expected to remain less than 10
knots. Direct impacts would entail MVFR ceilings, IFR or lower
visibilities and wind gusts of 20-30 knots. Most convection should
dissipate near 00Z Wednesday, with VFR conditions for the
remainder of the evening expected.
MARINE...
Persistent onshore flow is expected through tomorrow. By mid-
week, a weak low pressure system in the central Gulf could push
winds and seas higher. This low will track into Texas by Friday,
and winds are expected to drop back to 10 knots or less.
Additionally, winds and seas will be higher near any thunderstorm
activity that develops today and that also includes the
possibility of waterspouts.
Tides will be a problem through out the week. The southeasterly
winds will be in place across much of the Gulf and this will occur
in combination with the Spring Tide. This will cause some tidal
issues in the known trouble spots and a coastal Flood Advisory
remains in effect through midday Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 89 70 87 70 / 70 20 80 40
BTR 91 73 90 73 / 70 20 80 30
ASD 90 73 90 73 / 80 20 80 30
MSY 89 76 89 76 / 90 20 80 30
GPT 88 75 89 75 / 80 30 80 40
PQL 89 74 89 74 / 80 30 80 40
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 1 PM CDT Thursday for LAZ066>070-
076-078.
GM...None.
MS...Coastal Flood Advisory until 1 PM CDT Thursday for MSZ080>082.
GM...None.
&&The national radar mosaic for the moment the first event began.
3 flash flood. Local standard time, as filed.
Water from heavy rainfall caused flooding on Causeway Boulevard near the south end of the highway.
Broadcast media sent a picture of a car stalled in high water from heavy rainfall on Beverly Road.
Broadcast media relayed a video of water up the sides of cars on Plantation Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2022Every state in 2022This day in weather historyWarnings in Louisiana, August 2022
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: 1055142, 1055143, 1055144.