A dome of strong atmospheric high pressure - known locally as La Canicula, provided a prolonged period of hot to very hot temperatures combined with high humidity to lead to excessively heat index values in mid-June. High temperatures were in the upper 90s to middle 100s June 13th through June 17th.
Every event with a place to put it; 54 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.
A dome of strong atmospheric high pressure - known locally as La Canicula, provided a prolonged period of hot to very hot temperatures combined with high humidity to lead to excessively heat index values in mid-June. High temperatures were in the upper 90s to middle 100s June 13th through June 17th. Heat indices ranged from 116 to 125-degrees every afternoon across much of the area, from Hidalgo and Brooks County eastward. Heat indices ranged from 111 to 115 in these counties and farther west (Jim Hogg, Starr, and Zapata) on occasion through the period; these are considered Heat Advisory days with a slightly lower threshold for life-threatening conditions, but still dangerous.
The heat dome would continue through the end of June, with advisory or warning level heat index for all or part of the Rio Grande Valley and Deep South Texas through the period, and into July.
Local hospitals noted an increase in heat-related emergency room visits during this period when compared with the same period a year earlier, which was also hot but not at the level of 2023. Percentage increases ranged from 11 to 18 percent more visits during the month of June. Detailed information on heat-related illnesses (actual numbers of injuries or fatalities) was not known as of the end 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 Jun 13, 11:36 AM CST, 1 hour 17 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1236 PM CDT Tue Jun 13 2023
...New AVIATION...
.UPDATE...
Issued at 1136 AM CDT Tue Jun 13 2023
Latest surface observations across Deep South Texas already show
heat indices (HI) climbing above 100F for most locations late
this morning. Comparing with observations from about this time
yesterday morning, HI's are about a degree or two warmer on
average. With that said, decided to issue out a Heat Advisory for
all of Deep South Texas, with the exception of the Barrier
Island, between 1 PM and 7 PM CDT again today. Models indicate
some dry air mixing in across Zapata, northern Starr, and Jim Hogg
Counties after noon, which may inhibit HI rising above 110F.
Nevertheless, impacts will still be the same.
It is extremely important to keep yourself cool and hydrated this
week, especially if working outdoors for a prolonged period of
time. Wear lightweight and loose fitting clothing when possible.
67-Mejia
&&
.SHORT TERM...
(Today through Wednesday)
Issued at 254 AM CDT Tue Jun 13 2023
We'll start by looking back on Monday, not for the purpose of
"Monday morning quarterbacking," but rather to enter into the
official record what occurred and what did not occur.
Forecast highs were as follows: BRO 94, PIL 93, HRL 97, MFE 98, TXW
97, EBG 98, APY 103, HBV 100, and BKS 102. Observed highs were as
follows: BRO 95, PIL 94, HRL 95, MFE 98, TXW 99, EBG 98, APY 103,
HBV 101, and BKS 102. The forecast highs were the result of starting
with NBM guidance and adjusting downwards based upon the previous
few days of observations, so when compared with actual observed high
temperatures, forecaster intervention shows value.
At 125 PM CDT Monday, a Heat Advisory was issued for all of Deep
South Texas and the Rio Grande Valley except the island portions of
Cameron, Willacy, and Kenedy counties. This followed a 325 AM CDT
Monday Special Weather Statement where heat index values of 106 to
110 degrees were expected for the afternoon hours of Monday. The
criteria for a Heat Advisory for WFO BRO is heat indices of greater
than or equal to 111 degrees sustained for greater than or equal to
two consecutive hours. Looking at observed heat indices for the
above mentioned sites, the Heat Advisory appears to have verified
for only Hidalgo County and Brooks County. Again, this is not an
attempt to "Monday morning quarterback," but rather an attempt to
figure out where we are in order to know where we're going.
So, what does all of this mean for the short term forecast period
(Tuesday and Wednesday)? CONSShort was once again the model of
choice for dewpoint temperatures. Meanwhile, for high temperatures,
NBM was the starting point, and adjusting downwards of several
degrees was performed, especially over the central and western
portions of the BRO CWFA, where (likely) unrealistic highs were
progged by the NBM (APY 110-111, HBV 104-106, BKS 105-107, MFE 102-
104). The combination of the forecast ambient air temperatures and
forecast atmospheric moisture yields heat index values generally in
the range of 106 to 110 degrees for the afternoon hours of the
period, with isolated pockets of heat indices of 111 to 112 degrees.
Thus, will once again issue a Special Weather Statement for expected
heat index values today.
Finally, why has there been a disconnect between NBM's scorching
high temperatures and actual observed values over the past several
days? One reason could be the position of the 500 mb ridge, which is
progged by model guidance to remain centered over northeast Mexico
through at least the next 48 hours. Past exceptional heat events
were the result of a mid-level high centered more over the Four
Corners area of the United States. Another reason could be soil
moisture. On March 28, the U.S. Drought Monitor indicated Extreme
Drought within Zapata County, Jim Hogg County, Brooks County, most
of Kenedy County, and the western portion of Starr County, with the
remainder of the BRO CWFA (Hidalgo, Willacy, and Cameron counties)
generally in Severe Drought. As of June 6, no drought exists
anywhere within the BRO CWFA, the likely result of multiple
mesoscale convective systems producing scattered to numerous showers
and thunderstorms, many strong to severe. A portion of the solar
insolation is possibly being diverted for the evaporation of this
abundant soil moisture instead of being used 100 percent for heating
the air column, which would occur if soils were parched, such as in
a drought situation. How long the soil moisture will be a factor
remains to be seen in the coming days, especially since the 141 PM
CDT Monday Temperature and Precipitation Summary for Deep South
Texas lists .38 inches of evaporation for Brownsville, .36 inches
for Falcon Dam, .27 inches for McCook, .40 inches for Rio Grande
City, and .15 inches for Weslaco.
The bottom line? It's hot, and with the position of the above
mentioned 500 mb ridge possibly shifting more north and west over
time, the heat will be maintained, if not increased. Combined with
steadily drying soils and no significant precipitation likely with
the ridge hanging around, the likelihood of a widespread Heat
Advisory, and possibly Excessive Heat Warning, will increase with
time.
&&
.LONG TERM...
(Wednesday night through Monday)
Issued at 254 AM CDT Tue Jun 13 2023
The 500mb ridge settles across Deep South Texas by the weekend and
holds into next week, with surface high pressure across the Gulf.
This bumps heights toward 595 dam and will allow temperatures to
gain a few degrees, near record highs, through the remainder of
the long term period. So far this week, highs have underachieved
by a few degrees, but as the ridge builds stronger and the
overnight heat continues, there should be little to stop the
triple digit heat from taking over. Expect Heat Indices to top out
near 110-115 and locally higher every afternoon, driving Heat
Advisories through the period, although model guidance has not
been handling dewpoints very well either. Have trimmed dewpoints a
little lower.
Fire weather may become more of an issue over the weekend or into
early next week, with RH values along and west of US281 dropping
below 30 percent and potentially into the teens across Zapata
County, with 20 foot winds becoming breezy each afternoon. Still
feel most areas will fall below any fire weather criteria, but
current guidance now leans towards Fire Danger Statements
potentially Saturday through Monday.
&&
.AVIATION...
(18Z TAFS)
Issued at 1229 PM CDT Tue Jun 13 2023
MVFR ceilings over BRO will gradually lift and dissolve to VFR
sometime around 18-1830z. Otherwise and elsewhere, VFR conditions
will prevail through the rest of the afternoon. Widespread MVFR
ceilings are expected to return early this evening, after sunset,
and persist through mid-morning Wednesday. South/southeast winds
will be gusty this afternoon (gusts between 25-30 knots), even
gustier Wednesday afternoon with frequent gusts near 30 knots late
in the forecast period.
&&
.MARINE...
Issued at 254 AM CDT Tue Jun 13 2023
Now through Wednesday...Buoy 42020 reported south-southeast
winds around 18 knots gusting to around 21 knots with seas slightly
under 4.5 feet with a period of 5 seconds at 150 CDT/650 UTC. An
enhanced pressure gradient over the western Gulf of Mexico will
produce moderate to breezy winds and generally moderate seas along
the Lower Texas Coast during the period. Small Craft Exercise
Caution is likely, especially for the Laguna Madre and Gulf of
Mexico waters from 0 to 20 nautical miles offshore, and a Small
Craft Advisory cannot be ruled out for this area on Wednesday.
Wednesday Night through Monday...Southeasterly winds will maintain
Small Craft Caution conditions each afternoon into early evening
across the bay and nearshore waters, shifting further offshore
each night. Small Craft Advisories may be needed into Thursday and
again Monday, but at this time, it does not seem to be a slam dunk
SCA event.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 96 80 95 80 / 0 0 0 0
HARLINGEN 98 77 97 78 / 0 0 0 0
MCALLEN 101 78 99 79 / 0 0 0 0
RIO GRANDE CITY 104 76 106 77 / 0 0 0 0
SOUTH PADRE ISLAND 87 81 87 82 / 0 0 0 0
BAYVIEW/PORT ISABEL 95 77 92 79 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 7 PM CDT this evening for TXZ248>255-351-
353>355.
GM...None.
&&
SHORT TERM...66-Tomaselli
LONG TERM....56-Hallman
AVIATION...67-MejiaHazardous Weather Outlook National Weather Service Brownsville TX 404 AM CDT Tue Jun 13 2023 TXZ248>255-351-353>355-451-454-455-140915- 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- 404 AM CDT Tue Jun 13 2023 This Hazardous Weather Outlook is for portions of Deep South Texas. .DAY ONE...Today and Tonight There is a Moderate Risk of rip currents along the lower Texas coast. Heat Index values of 105 to 110 degrees are possible this afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Heat Index values between 110 and 116 degrees are expected during the afternoon hours of the period. Heat Advisories may be needed for portions or all of Deep South Texas and the Rio Grande Valley, and an Excessive Heat Warning cannot be ruled out. An elevated risk of rip currents and longshore currents is possible at the beaches of South Padre Island and at Boca Chica Beach through the period. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. GMZ130-132-135-150-155-170-175-140915- 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- 404 AM CDT Tue Jun 13 2023 This Hazardous Weather Outlook is for portions of The Gulf of Mexico and The Laguna Madre. .DAY ONE...Today and Tonight Small Craft Advisories may be needed across all or portions of the lower Texas coastal waters this afternoon into tonight. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Small Craft Advisories will be possible along the Lower Texas Coast Wednesday into Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
32 heat, 22 excessive heat. Local standard time, as filed.
It is reasonable to infer that Northern Hidalgo County reached Excessive 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 June 13th.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 116 degrees between 1:53PM CDT and 6:53PM CDT the afternoon of June 13th. The highest heat index was recorded at 4:53PM CDT of 121 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 121 degrees at 5:55PM CDT.
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 June 13th. 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 ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations prior to the spike and just after the period of these values gives a better range of 111 degrees or higher.
The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 7:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.
The Cameron County ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations along the bayside of Cameron County with those of inland Kenedy (TW100) and Kleberg County to the north suggests similar values occurred in Coastal Kenedy at a bit later time, associated with the arrival of the sea breeze gives a better range of 111 degrees or higher.
The Jim Hogg County AWOS reported several hours of heat index between 111 and 113 during the afternoon of June 13, 2023. Dangerous heat began at around 315 PM CDT and continued through 630 PM CDT. Peak values of 113 occurred at 415 PM CDT. The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded values of 111 to 112 during the same time frame.
The Cameron County ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations along the bayside of Cameron County with those of inland Kenedy and Kleberg County to the north suggests similar values occurred in Coastal Willacy at the same time as well - prior to the spike and just after the period of these values gives a better range of 111 degrees or higher.
The Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees at 3:52PM CDT the afternoon of June 13th. The highest heat index recorded was at 3:52PM CDT of 118 degrees.
The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 4:15PM CDT and 7:15PM CDT the afternoon of June 13th. The highest heat index was recorded at 6:35PM CDT of 123 degrees.
The Cameron County ASOS reported heat index between 111 and 115 degrees from approximately 12:30 PM through 4:30 PM on the 13th. Interpolating between observations prior to the spike and just after the period of these values gives a better range of 111 degrees or higher. Similar values and times were reported at Laguna Atascosa National Wildlife Refuge.
The Cameron County Airport ASOS near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 14th, peaking at 115 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 113 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 116 degrees between 1:55PM CDT and 4:55PM CDT the afternoon of June 14th. The highest heat index was recorded at 3:53PM CDT of 118 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 118 degrees at 4:15PM CDT.
It is reasonable to infer that Northern Hidalgo County reached Excessive Heat criteria due to readings at the McAllen-Miller International Airport and Edinburg International Airport, both of which reached criteria on June 14th.
The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 7:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 113 degrees across inland Willacy County during the afternoon of June 14th. 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 near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 14th, peaking at 115 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 113 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100) is a good proxy for Coastal Kenedy, with a slightly later start and end time.
The Zapata County Airport AWOS reported a heat index of 111 by 4:35 PM CDT, with 111 or higher values persisting until approximately 530 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 3 hours in a few locations.
Though Jim Hogg County AWOS reported no hours of heat index reaching or exceeding 111 degrees and 113 during the afternoon of June 14, 2023, the Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 113 between 5 PM and 730 PM CDT, after humidity recovered during the late afternoon.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 116 degrees between 5:30PM CDT and 6:30PM CDT the afternoon of June 14th. The highest heat index was recorded at 5:30PM CDT of 119 degrees.
The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100) is a good proxy for Coastal Kenedy, with a slightly earlier start time and later end time.
The Cameron County Airport ASOS near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 114 degrees across inland Willacy County during the afternoon of June 15th. Slightly lower values (below excessive heat criteria, or 116F) 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 Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees at 2:52PM CDT the afternoon of June 15th. The highest heat index recorded was at 2:52PM CDT of 116 degrees. The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees between 1:53PM CDT and 4:53PM CDT the afternoon of June 15th. The highest heat index recorded was at 3:15PM CDT of 118 degrees.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 116 degrees between 2:15PM CDT and 5:53PM CDT the afternoon of June 15th. The highest heat index was recorded at 5:53PM CDT of 119 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 120 degrees at 3:35PM CDT.
It is reasonable to infer that Northern Hidalgo County reached Excessive 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 June 15th.
Though Jim Hogg County AWOS reported no hours of heat index reaching or exceeding 111 degrees during the afternoon of June 15, 2023, the Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 115 between 3 PM and 7 PM CDT, after humidity recovered during the late afternoon. With Jim Hogg County AWOS falling just shy of 111, proxy observations suggest the majority of the county reached local advisory-level criteria.
The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 6:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 116 degrees between 4:20PM CDT and 6:10PM CDT the afternoon of June 15th. The highest heat index was recorded at 5:10PM CDT of 119 degrees.
The Zapata County Airport AWOS reported a heat index of 111 by around 4 PM CDT, with 111 or higher values persisting until approximately 545 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 3 to 4 hours in a few locations.
The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 5:15PM CDT and 6:35PM CDT the afternoon of June 15th. The highest was recorded at 5:15PM CDT of 117 degrees.
The Cameron County Airport ASOS near Bayview reported around six hours of heat index between 111 and 115 degrees during the late morning and afternoon of June 17th, peaking at 117 at 3:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 degrees roughly during the same time period.
The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 3:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 114 degrees across inland Willacy County during the afternoon of June 16th. Slightly lower values (below excessive heat criteria, or 116F) 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 near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100), which had slightly lower heat index values (generally, 111 to 115) is a good proxy for Coastal Kenedy. This site peaked at around 116 degrees at 405 PM CDT.
The Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees between 12:52PM CDT and 3:52PM CDT the afternoon of June 16th. The highest heat index recorded was at 12:52PM CDT of 118 degrees. The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees at 12:53PM CDT the afternoon of June 16th. The highest heat index recorded was at 12:53PM CDT of 117 degrees.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 116 degrees between 12:53PM CDT and 5:53PM CDT the afternoon of June 16th. The highest heat index was recorded at 5:53PM CDT of 121 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 120 degrees at 3:55PM CDT.
It is reasonable to infer that Northern Hidalgo County reached Excessive 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 June 16th.
The Jim Hogg County AWOS reported approximately 6 hours of heat index reaching or exceeding 111 degrees during the afternoon of June 16, 2023, peaking at 115 degrees at 735 PM CDT. The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 115 between 2 PM and 7 PM CDT, after humidity remained steady between 35 and 40 percent covered during the late afternoon.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 116 degrees between 2:40PM CDT and 3:20PM CDT the afternoon of June 16th. The highest heat index was recorded at 2:40PM CDT of 117 degrees.
The Zapata County Airport AWOS reported a heat index of 111 by around 3 PM CDT, with 111 or higher values persisting until approximately 8 PM CDT. Peak value was just below 113 at 415 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 5 to 7 hours in a few locations during the same time.
The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 3:35PM CDT and 6:55PM CDT the afternoon of June 16th. The highest was recorded at 4:35PM CDT of 127 degrees.
The Cameron County Airport ASOS near Bayview reported around five hours of heat index between 111 and 115 degrees during the late morning and afternoon of June 17th, peaking at 117 at 12:49 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
The Cameron County Airport ASOS near Bayview reported around five hours of heat index between 111 and 115 degrees during the afternoon of June 17th, peaking at 117 at 12:49 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period. Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.
The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 11:35AM CDT and 6:55PM CDT the afternoon of June 17th. The highest was recorded at 4:55PM CDT of 119 degrees.
The Cameron County Airport ASOS near Bayview reported around seven hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100), which had similar heat index values (generally, 111 to 115, briefly peaking at 118 degrees around 6 PM CDT) is a good proxy for Coastal Kenedy.
The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 116 degrees between 12:53PM CDT and 4:53PM CDT the afternoon of June 16th. The highest heat index was recorded at 1:53PM CDT of 117 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 119 degrees at 2:35PM CDT.
It is reasonable to infer that Northern Hidalgo County reached Excessive 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 June 17th.
The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees between 12:53PM CDT and 2:53PM CDT the afternoon of June 17th. The highest heat index recorded was at 12:53PM CDT of 117 degrees.
By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 114 degrees across inland Willacy County during the afternoon of June 17th. Slightly lower values (below excessive heat criteria, or 116F) 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 Jim Hogg County AWOS reported approximately 3 hours of heat index reaching or exceeding 111 degrees during the afternoon of June 16, 2023, peaking just below 114 degrees at 535 PM CDT. The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 114 between 145 PM and 705 PM CDT, as humidity held firm between 39 and 43 percent during the late afternoon.
The Zapata County Airport AWOS reported a heat index of 111 by around 215 PM CDT, with 111 or higher values persisting until approximately 630 PM CDT. Peak value was just below 114 at 235 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 4 to 6 hours in a few locations.
The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 116 degrees between 4:50PM CDT and 6:50PM CDT the afternoon of June 17th. The highest heat index was recorded at 6:00PM CDT of 121 degrees.
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, June 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: 1110755, 1110778, 1116380, 1116388, 1116413, 1116447, 1116402, 1116445, 1110787, 1110722, 1116919, 1116449, 1110756, 1110773, 1116427, 1116437, 1116454, 1116393, 1116434, 1110791, 1117036, 1116442, 1116920, 1116914, 1110788, 1110765, 1110783, 1116911, 1116913, 1110792, 1116912, 1110723, 1116917, 1116921, 1117041, 1117039, 1110789, 1110766, 1110785, 1117051, and more.