Persistent mid-level ridging aloft combined with ample low-level moisture to provide high heat and humidity across the Rio Grande Valley and Deep South Texas much of August.
Every event with a place to put it; 52 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 BRO wrote it up.
Persistent mid-level ridging aloft combined with ample low-level moisture to provide high heat and humidity across the Rio Grande Valley and Deep South Texas much of August.
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 Brownsville, TX wrote its last area forecast discussion before the first event at Aug 6, 5:33 AM CST, 5 hours 20 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
633 AM CDT Sun Aug 6 2023
...New AVIATION...
.SHORT TERM...
(Today through Monday)
Issued at 352 AM CDT Sun Aug 6 2023
Mid-level ridging will remain in place through the period. Strong
subsidence will maintain hot to very hot, humid, and rain-free
conditions across Deep South Texas through the short-term. High
temperatures for today and tomorrow are expected to remain above
normal, with highs generally in the 100s, with 90s along the coast.
Will continue to lean towards a blend of the NBM and CONSSHORT for
the dewpoints through Monday, as the NBM seems a little high on
dewpoints. A slight increase in heat and less mix-out of dewpoints
should support higher heat indices today and Monday. Heat indices
are expected to range between 108 to 115 degrees across much of the
area this afternoon. A Heat Advisory remains in effect Hidalgo,
Brooks, Starr, and the Inland and Coastal portions of Kenedy,
Willacy, and Cameron Counties from 1 PM this afternoon until 7 PM
this evening. Will issue an SPS for elevated heat for Jim Hogg and
Zapata counties, but a few locations may briefly exceed 111 degrees
late in the afternoon. The low temperatures for tonight are expected
to be in the upper 70s to low 80s.
&&
.LONG TERM...
(Monday Night through Saturday)
Issued at 352 AM CDT Sun Aug 6 2023
No significant synoptic changes during this portion of the total
forecast. The onslaught of heat will persist with broad 500 mb
high pressure remaining the dominant feature over the BRO CWFA.
With the exception of a highly isolated nocturnal streamer shower
over the far offshore Gulf of Mexico waters, dry weather is a
certainty inland. Well above normal daytime high temperatures will
continue to be the rule, and muggy overnight lows will provide
little relief. The only smidgen of relief will come in the form of
a breezy to windy onshore flow, courtesy of the ongoing inland
thermal low and marine high pressure interaction. In fact, wind
speeds may be strong enough Wednesday into Wednesday night to
require a Wind Advisory for the eastern three counties.
Finally, a Heat Advisory may be needed for portions or all of
Deep South Texas and the Rio Grande Valley throughout the long
term period, and an Excessive Heat Warning cannot be ruled out for
the same time frame for a select few counties.
&&
.AVIATION...
(12Z TAFS)
Issued at 629 AM CDT Sun Aug 6 2023
Mostly clear skies and light south-southeast winds prevail across
Deep South Texas early this morning. Will mention brief TEMPO
wording at BRO due to some passing low clouds. Otherwise, VFR
conditions are expected for the next 24 hours. Light southeast
winds this morning will increase and become gusty later this
morning into the afternoon, with gusts up to 25 kts are likely
through around sunset.
&&
.MARINE...
(Today through Monday)
Issued at 352 AM CDT Sun Aug 6 2023
Generally favorable conditions are expected through the period as
high pressure across the central Gulf maintains generally
moderate onshore flow and low to moderate seas. Slightly higher
winds this afternoon and Monday afternoon will lead to Small Craft
Exercise Caution conditions, especially on the Laguna Madre.
(Monday Night through Saturday)
Less than ideal marine conditions will occur during the period,
due to an intensifying surface pressure gradient. A combination of
Small Craft Exercise Caution and Small Craft Advisory is expected
daily along the Lower Texas Coast, mainly due to winds.
&&
.FIRE WEATHER...
Issued at 352 AM CDT Sun Aug 6 2023
Dry to critically dry fuels, relative humidity falling to 20 to
30 percent west of US 281 and 30 to 40 percent near the coast, and
breezy 20-foot level winds will require a Rangeland Fire Danger
Statement for this afternoon. The Fire Danger Statement is in
effect from 1 PM this afternoon until 7 PM this evening for all
but the coastal and barrier island zones.
&&
.CLIMATE...
Issued at 352 AM CDT Sun Aug 6 2023
More record breaking temperatures will be possible today and
Monday. Brownsville's record high for today is 100 degrees, which
is currently forecast to be tied. Moday's high temperature at
Brownsville is 101 and the forecast high is 100. Harlingen's
record high for today is 101 degrees and the forecast high is 102.
Monday's record high temperature is 103 and the forecast high is
102.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 98 82 98 82 / 10 0 0 0
HARLINGEN 101 77 102 78 / 0 0 0 0
MCALLEN 103 79 103 80 / 0 0 0 0
RIO GRANDE CITY 106 78 106 78 / 0 0 0 0
SOUTH PADRE ISLAND 90 82 90 82 / 10 0 0 0
BAYVIEW/PORT ISABEL 97 80 98 80 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening
for TXZ250>255-351-353>355.
GM...None.
&&
SHORT TERM...63-KC
LONG TERM....66-Tomaselli
AVIATION...63-KCHazardous Weather Outlook...UPDATED National Weather Service Brownsville TX 908 AM CDT Sun Aug 6 2023 TXZ248>255-351-353>355-451-454-455-062100- Zapata-Jim Hogg-Brooks-Inland Kenedy-Starr-Southern Hidalgo- Inland Willacy-Inland Cameron-Coastal Kenedy-Northern Hidalgo- Coastal Willacy-Coastal Cameron-Kenedy Island-Willacy Island- Cameron Island- 908 AM CDT Sun Aug 6 2023 This Hazardous Weather Outlook is for portions of Deep South Texas. .DAY ONE...Today and Tonight A Heat Advisory is in now in effect for all of Deep South Texas and the Rio Grande Valley except the island portions of Cameron, Willacy, and Kenedy counties from 1 PM CDT to 7 PM CDT. .DAYS TWO THROUGH SEVEN...Monday through Saturday Additional Heat Advisories are possible for portions or all of Deep South Texas and the Rio Grande Valley through the entire period. An Excessive Heat Warning may also be needed through the entire period for select counties. An elevated risk of rip currents is possible at the beaches of South Padre Island and at Boca Chica Beach Tuesday through Saturday. A Wind Advisory may be be needed for portions or all of the eastern three counties of Deep South Texas and the Rio Grande Valley Wednesday through Wednesday night. .SPOTTER INFORMATION STATEMENT... Skywarn spotter activation will not be needed. GMZ130-132-135-150-155-170-175-062100- Laguna Madre from the Port of Brownsville to the Arroyo Colorado- Laguna Madre from the Arroyo Colorado To 5 NM north of Port Mansfield TX- Laguna Madre from 5 nm north of Port Mansfield to Baffin Bay TX- Gulf waters from Port Mansfield to the Rio Grande out 20 nm- Gulf waters from Baffin Bay to Port Mansfield out 20 nm- Gulf waters from Port Mansfield to the Rio Grande extending from 20 to 60 nm- Gulf waters from Baffin Bay to Port Mansfield extending from 20 to 60 nm- 908 AM CDT Sun Aug 6 2023 This Hazardous Weather Outlook is for portions of The Gulf of Mexico and The Laguna Madre. .DAY ONE...Today and Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Monday through Saturday A Small Craft Advisory is possible along the Lower Texas Coast Tuesday through Friday. .SPOTTER INFORMATION STATEMENT... Skywarn spotter activation will not be needed. 53
The national radar mosaic for the moment the first event began.
52 heat. Local standard time, as filed.
The Brownsville-South Padre International ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 3:53 PM CDT on August 6th.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of August 6th. Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 6th.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 6th. By proxy, it can be assumed that Coastal Willacy County had similar conditions.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 6th. By proxy, it can be assumed that Coastal Kenedy County had similar conditions. In addition, the inland location in Sarita (northwest Kenedy) had more than 3 hours of heat index of 111 or higher.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 2:53PM CDT and 3:53PM CDT the afternoon of August 6th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 1:15PM CDT and 4:35PM CDT the afternoon of August 6th.
It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on August 6th.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 1:20PM CDT and 4:40PM CDT the afternoon of August 6th.
The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 117 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 110 during the same period. By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 114.
The Brooks County Airport AWOS reported a heat index of 111 by 2:15 PM CDT, with 111 or higher values persisting until approximately 6:35 PM CDT on August 6th.
The Harlingen-Valley International Airport ASOS reported a heat index of 111 by 1:52 PM CDT, with 111 or higher values persisting until approximately 4:52 PM CDT on August 7th. The Brownsville-South Padre International ASOS reported a heat index of 111 by 10:53 AM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 7th.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of August 7th. Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 7th.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 7th. By proxy, it can be assumed that Coastal Willacy County had similar conditions.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 7th. By proxy, it can be assumed that Coastal Kenedy County had similar conditions. The Texas Mesonet location in Sarita (northwest Kenedy) recorded three hours of these conditions around the same time.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 1:53PM CDT and 4:53PM CDT the afternoon of August 7th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 1:35PM CDT and 4:55PM CDT the afternoon of August 7th.
It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on August 7th.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 2:20PM CDT and 5:20PM CDT the afternoon of August 7th.
The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 117 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 110 during the same period. By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 114.
The Brooks County Airport AWOS reported a heat index of 111 by 3:35 PM CDT, with 111 or higher values persisting until approximately 7:35 PM CDT on August 7th.
The Harlingen-Valley International Airport ASOS reported a heat index of 111 by 12:52 PM CDT, with 111 or higher values persisting until approximately 1:52 PM CDT on August 8th. The Brownsville-South Padre International ASOS reported a heat index of 111 by 10:53 AM CDT, with 111 or higher values persisting until approximately 2:53 PM CDT on August 8th.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of August 8th. Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 3:53 PM CDT on August 8th.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 3:53 PM CDT on August 8th. By proxy, it can be assumed that Coastal Willacy County had similar conditions.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 3:53 PM CDT on August 8th. By proxy, it can be assumed that Coastal Kenedy County had similar conditions. The Texas Water Development Board mesonet site at Sarita (northwest Kenedy) also had 3 hours of these conditions.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 1:53PM CDT and 2:53PM CDT the afternoon of August 8th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 11:55AM CDT and 4:15PM CDT the afternoon of August 8th.
It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on August 8th.
The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 117 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 109 during the same period. By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 114.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 2:20PM CDT and 5:20PM CDT the afternoon of August 8th.
The Brooks County Airport AWOS reported a heat index of 111 by 4:55 PM CDT, with 111 or higher values persisting until approximately 6:35 PM CDT on August 8th.
The Harlingen-Valley International Airport ASOS reported a heat index of 111 by 11:52 AM CDT, with 111 or higher values persisting until approximately 3:52 PM CDT on August 9th. The Brownsville-South Padre International ASOS reported a heat index of 111 by 10:53 AM CDT, with 111 or higher values persisting until approximately 3:53 PM CDT on August 9th.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of August 9th. Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 2:53 PM CDT on August 9th.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 2:53 PM CDT on August 9th.By proxy, it can be assumed that Coastal Willacy County had similar conditions.
The Cameron County Airport ASOS reported a heat index of 111 by 11:53 AM CDT, with 111 or higher values persisting until approximately 2:53 PM CDT on August 9th.By proxy, it can be assumed that Coastal Kenedy County had similar conditions. The Texas Water Development Board location in Sarita (northwest Kenedy) also had 2 hours duration of 111 or higher heat index.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 1:53PM CDT and 3:53PM CDT the afternoon of August 9th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 1:15PM CDT and 4:15PM CDT the afternoon of August 9th.
It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on August 9th.
The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 117 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 109 during the same period. By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 114.
The Brooks County Airport AWOS reported a heat index of 111 by 2:15 PM CDT, with 111 or higher values persisting until approximately 4:45 PM CDT on August 9th.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 3:20PM CDT and 5:30PM CDT the afternoon of August 9th.
The Zapata County Airport AWOS reported a heat index of 111 by 3:55 PM CDT, with 111 or higher values persisting until approximately 6:55 PM CDT on August 9th.
The Harlingen-Valley International Airport ASOS reported a heat index of 111 by 12:52 PM CDT, with 111 or higher values persisting until approximately 4:52 PM CDT on August 10th. The Brownsville-South Padre International ASOS reported a heat index of 111 by 10:44 AM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 10th.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of August 10th. Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 10th.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 12:53PM CDT and 4:53PM CDT the afternoon of August 10th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 1:15PM CDT and 6:35PM CDT the afternoon of August 10th.
It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on August 10th.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 10th. By proxy, it can be assumed that Coastal Willacy County had similar conditions.
The Cameron County Airport ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on August 10th. By proxy, it can be assumed that Coastal Kenedy County had similar conditions. At the Texas Water Development Board's mesonet site in Sarita, more than 3 hours of conditions was reported.
The Brooks County Airport AWOS reported a heat index of 111 by 1:55 PM CDT, with 111 or higher values persisting until approximately 7:15 PM CDT on August 10th.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 2:00PM CDT and 5:30PM CDT the afternoon of August 10th.
The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 117 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 109 during the same period. By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 114.
The Zapata County Airport AWOS reported a heat index of 111 by 1:15 PM CDT, with 111 or higher values persisting until approximately 6:35 PM CDT on August 10th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2023Every state in 2023This day in weather historyWarnings in Texas, 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: 1118543, 1118571, 1118531, 1136104, 1136105, 1118536, 1118564, 1118549, 1118558, 1118523, 1118544, 1118572, 1118532, 1136106, 1136107, 1118538, 1118565, 1118550, 1118559, 1118524, 1118545, 1118573, 1118533, 1136108, 1136109, 1118539, 1118566, 1118560, 1118551, 1118525, 1118546, 1118574, 1118534, 1136110, 1136111, 1118540, 1118567, 1118561, 1118526, 1118552, and more.