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; 28 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 2, 5:30 AM CST, 3 hours 30 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
630 AM CDT Wed Aug 2 2023
...NEW AVIATION...
.SHORT TERM...
(Today through Thursday)
Issued at 255 AM CDT Wed Aug 2 2023
Early this morning the 597dam upper level high was centered just
east of Durant, Oklahoma with our region remaining on the eastern
periphery. At the surface, a very weak surface boundary resides
over our region generally along the I10/12 corridor. This feature
along with other mesoscale boundaries and a subtle upper impulse
may be just enough to spark some afternoon convection, especially
over the western tier later this afternoon or early evening.
Forecast soundings from both mesoscale and global guidance
indicate downdraft CAPE values around 1200-1300 J/kg respectively.
Although not at high as a day or two ago, these numbers are still
more that sufficient for a strong wind gust or two in the
strongest convection. With large scale upper level descent, expect
coverage to remain a bit on the limited side as well as limited
vertical growth, however, a strong to marginally severe storm or
two cannot be ruled out later this afternoon.
Rainfall would be a bit of a relief not only in terms of heat, but
also the ongoing rainfall deficit. However, relief will be rather
short as heat index values will have already hit excessive heat
criteria by the time convection starts to fire (in most cases for
several hours). Continued the Excessive Heat Warning for the LA
Parishes and SW Mississippi and kept the Heat Advisory for the
Mississippi Gulf Coast as max temperatures would be slightly lower
over those areas in contrast to locations along the Atchafalaya.
Tonight the ridge will continue to spread eastward and center near
the ArkLaTex region. This will set the stage for another hot day
on Thursday, however, with a slightly lower temps/heat index
values, we do not meet Excessive Heat Criteria for most of the
CWFA. That said, hold the applause as we will still be well within
the Heat Advisory range, so will be adding this headline for
Thursday areawide. Speaking of Thursday, low-end climo POPs are
in the forecast, however, low confidence at this juncture with
only the CMC and ECMWF highlighting a very subtle QPF signal. For
the sake of continuity, will continue to allow the current 20s/30s
ride, but if trends continue Thursday may be a dry day across the
CWFA. (Frye)
&&
.LONG TERM...
(Thursday night through Tuesday)
Issued at 255 AM CDT Wed Aug 2 2023
Main story to start off is just a continuation of the short term
pattern into the start of the long term period. H5 high still
sitting in closer proximity. Continued hot (likely heat headlines)
and low-end rain probabilities. However, going into the upcoming
weekend there will begin to be a slight pattern change that takes
place across the region. First, the center of the highest heights
will retrograde back across the Texas Hill Country by Saturday.
There is still some elongated shortwave riding over the region,
which will continue the hot and mostly dry weather. Upstream we
will be watching an upper level weakness develop which should
continue to flatten the ridge over the central Gulf Coast late
Saturday and into Sunday. With the weakness becoming more
pronounced late into the weekend, introduced a bit higher POPs,
especially across the eastern tier closer to the developing upper
trof. The best potential would likely be during the afternoon and
evening hours. Although the convective temp will be lower and
rainfall coverage may be more expansive, again save your applause
because just prior to reaching convective temperature most of the
forecast area will likely achieve heat headline criteria. There
appears to be some good news going into the start of the new
workweek. With the high retrograding our region will remain in the
more active northwesterly flow around its eastern periphery. This
will place the ridge runner H5 impulse track over our region
early next week. Assuming no changes this would mean a bit more
convection and perhaps much needed rainfall to at least portions
of the forecast area with MSY, GPT, and ASD all running 15 to 20
inches below average for the year. (Frye)
&&
.AVIATION...
(12Z TAFS)
Issued at 627 AM CDT Wed Aug 2 2023
VFR conditions expected through much of the period. Winds should
stay generally less than 10kt and vary based on lake/sea breeze
respectively. Convection will be possible albeit limited in
coverage with the best potential over BTR and HUM...maybe as far
east as MSY. Otherwise, the only other concern overnight tonight
or early Thursday morning will be lower VIS for MCB. The signal
isn't strong and confidence is too low to add MVFR VIS at this
point, but subsequent updates may include this potential if
confidence increases through the day. (Frye)
&&
.MARINE...
Issued at 255 AM CDT Wed Aug 2 2023
Favorable marine conditions are expected outside of convection. Late
night or morning convection across the local waters will continue
with locally higher winds and seas expected. Otherwise, winds should
remain on the lighter side through the week with a gradual wind
transition to a more southwesterly direction as a surface high
pressure begins to move downstream over the far eastern portions of
the Gulf of Mexico. (Frye)
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 98 75 98 75 / 30 10 20 10
BTR 100 80 100 80 / 30 20 20 0
ASD 98 78 98 79 / 20 10 20 0
MSY 98 81 98 81 / 30 10 30 0
GPT 97 79 95 80 / 20 10 30 10
PQL 99 77 96 78 / 20 10 30 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this
evening for LAZ034>037-039-046>048-056>060-064>071-076>090.
Heat Advisory from 10 AM to 7 PM CDT Thursday for LAZ034>037-039-
046>048-056>060-064>071-076>090.
GM...None.
MS...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this
evening for MSZ068>071.
Heat Advisory from 10 AM to 7 PM CDT Thursday for MSZ068>071-077-
083>088.
Heat Advisory from 10 AM this morning to 7 PM CDT this evening
for MSZ077-083>088.
GM...None.
&&
SHORT TERM...RDF
LONG TERM....RDF
AVIATION...RDF
MARINE...RDFThe national radar mosaic for the moment the first event began.
36 excessive heat. Local standard time, as filed.
Very hot and humid weather occurred for all of southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 southeast Louisiana on August 2nd. 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 Louisiana in 2023Every state in 2023This day in weather historyWarnings in Louisiana, 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 2026-10-01. Each event’s entry at NCEI: 1137360, 1137361, 1137362, 1137363, 1137364, 1137365, 1137366, 1137367, 1137368, 1137369, 1137370, 1137371, 1137372, 1137373, 1137374, 1137375, 1137376, 1137377, 1137378, 1137379, 1137380, 1137381, 1137382, 1137383, 1137384, 1137385, 1137386, 1137387, 1137388, 1137389, 1137390, 1137391, 1137392, 1137393, 1137394, 1137395.