An expansive ridge sat over the southern portion of the CONUS. This ridge caused extreme record-breaking temperatures across much of the south, including southeast Louisiana and southern Mississippi.
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.
An expansive ridge sat over the southern portion of the CONUS. This ridge caused extreme record-breaking temperatures across much of the south, including southeast Louisiana and southern Mississippi. The record-breaking temperatures paired with high humidity values caused the heat to be excessive across southeast Louisiana and southern Mississippi.
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, 3:16 AM CST, 6 hours 44 minutes earlier.
Area Forecast Discussion
National Weather Service New Orleans LA
416 AM CDT Wed Aug 9 2023
...New SHORT TERM, LONG TERM, AVIATION, MARINE...
.SHORT TERM...
(Today through Thursday)
Issued at 401 AM CDT Wed Aug 9 2023
Synoptically, there are very little changes in the short term. We
continue to hug the NBM75th percentile as far as daily highs go.
Precip chances will be 20-30% for most areas. Tried to give areas
that should get some sh/ts activity 30% numbers. But trying to find
where the first sh/ts develops is like finding where the first
bubble will develop in a pot of water before boiling. The only place
that is driven with some kinematics involved is over the Miss Sound
this morning where the nocturnal marine jet is most active and
driving a few showers to develop along its left flank. These showers
could become a ts or two as the morning progresses, but the best
thing is its bringing some much needed rain to some isolated
locations on the Miss Gulf coast. There could be a few other areas
of SELA that get some nocturnals moving in off the gulf this morning
mainly around Houma and points east. This is occurring as PW values
have increased a bit causing the convective temp to fall closer to
SSTs. And the most unstable time for our marine environment is just
before and around sunrise. This may also cause the highest chances
of rain to be during the morning hours. But there will be several
sh/ts around during the afternoone hours as well. Obviously will be
leaving the hazards alone for land areas today and Thursday.
Downburst numbers are highest to the east, so if there are any
issues with ts winds, best chances would be toward the GPT area.
&&
.LONG TERM...
(Thursday night through Tuesday)
Issued at 401 AM CDT Wed Aug 9 2023
Friday and/or Saturday should be the warmest of the next several
days as the stacked ridge doubles down on the area. But models
continue to show synoptic changes over the weekend into the first of
next week. One thing that shows up is higher PWs by late Sunday. PWs
increase because there is more moisture in the vertical and when
there is deeper moisture, temps have a much harder time getting to
the century mark. Eventhough, the NBMdeterministic is trying to move
close to the NBM90-75, we will be keeping these temps a bit "cooler"
(nothing cool about it though) than advertised in model solutions
and stick closer to what the big picture offers which is more
between the NBM75-50. Most areas should begin to see some rain
possibly by late in the day Sunday and again Monday as an eastery
wave moves through the gulf which is most evident in PW fields. The
cloud cover caused by more sh/ts around would also help out as well.
Now, as we all know models do flip and flop all over the place,
moreso in the extended, which is why we try to find those variables
that show a trend from run to run. When models jump to a conclusion
that shows up the first time, its hard to jump on that solution
unless it starts to show up again and again, hence...a trend. But
eventhough we will not be showing this big change in model solutions
in the current fcast, we will still discuss it here because ALL
global suites are showing this feature and agree on spatial and
temporal resolution which can eventually lead to a trend developing.
Now for the moment you are waiting for, a bona fide "modeled" cold
front. Ok, a few caveats first. This is the first time these models
have shown this, but all of them are showing this very solution with
very similar timing and placement. Normally when a cold front moves
into the area this time of year, it can make temps warmer. But this
one actually has a thermal gradient, not just a dew pt gradient,
which is how we normally find fronts this time of year. All models
have this front moving into the area before stalling Tue night. We
will see.
&&
.AVIATION...
(12Z TAFS)
Issued at 401 AM CDT Wed Aug 9 2023
VFR through this fcast pack. The best chance, which is not very
high, of getting a TSRA will be HUM and GPT today mainly during the
morning hours. Winds with any TSRA could be stong causing wind
direction to shift suddenly. All activity should dissipate shortly
after sunset.
&&
.MARINE...
Issued at 401 AM CDT Wed Aug 9 2023
Surface high pressure remains through much of this week. This will
keep winds peaking to only around 10kt in most areas. The nocturnal
jet that develops mainly across the sounds will be the only areas
that peak around 15 to 20kt during the evening and predawn morning
hours and for this another caution statement has been posted for
tonight. A few sh/ts should develop this morning over some of our
coastal waters and move inland this morning and in the vicinity of
any storms winds could be higher.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 97 76 99 76 / 10 0 10 0
BTR 100 81 101 81 / 20 0 10 0
ASD 98 81 100 80 / 20 0 20 0
MSY 98 82 101 83 / 20 10 20 0
GPT 95 81 98 81 / 30 10 20 10
PQL 96 80 98 80 / 30 10 20 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Excessive Heat Warning from 11 AM this morning to 7 PM CDT this
evening for LAZ034>037-039-046>048-056>060-064>071-076>090.
Excessive Heat Watch from Thursday morning through Thursday
evening for LAZ034>037-039-046>048-056>060-064>071-076>090.
GM...None.
MS...Excessive Heat Warning from 11 AM this morning to 7 PM CDT this
evening for MSZ068>071-077-083>088.
Excessive Heat Watch from Thursday morning through Thursday
evening for MSZ068>071-077-083>088.
GM...None.
&&
SHORT TERM...TE
LONG TERM....TE
AVIATION...TE
MARINE...TEThe national radar mosaic for the moment the first event began.
11 excessive heat. Local standard time, as filed.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
Very hot and humid weather occurred for all of southern Mississippi on August 9th. High temperatures were in the upper 90s to 100 degrees with heat indices were in the 113 to 115 degree range each afternoon.
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, August 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: 1137696, 1137697, 1137698, 1137699, 1137700, 1137701, 1137702, 1137703, 1137704, 1137705, 1137706.