A stout mid level ridge built over Deep South Texas during the last few days of August and into the beginning of September, allowing high temperatures to climb. These high temperatures combined with high surface relative humidity, allowed afternoon heat indices to climb to a dangerous 111 degrees or greater for a couple of hours in the afternoon of September 1st in populated areas of the Rio…
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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 BRO wrote it up.
A stout mid level ridge built over Deep South Texas during the last few days of August and into the beginning of September, allowing high temperatures to climb. These high temperatures combined with high surface relative humidity, allowed afternoon heat indices to climb to a dangerous 111 degrees or greater for a couple of hours in the afternoon of September 1st in populated areas of the Rio Grande Valley.
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 Sep 1, 5:52 AM CST, 5 hours 8 minutes earlier.
Area Forecast Discussion
National Weather Service Brownsville TX
Issued by National Weather Service Austin/San Antonio TX
652 AM CDT Tue Sep 1 2020
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION.../12Z TAFS issued by NWS Austin/San Antonio/
Main story continues to be the strong south winds and today looks
to show the highest wind speeds of the week. Midday winds at HRL
and BRO could approach 35 Knots. Satellite shows a bit more MVFR
cig coverage so will keep in prevailing cigs for the first 3 or 4
hours. Less wind is expected tonight, and will follow along with
MOS guidance that the low cigs do not return at the end of the TAF
periods Wednesday morning.
&&
.PREV DISCUSSION... /issued 440 AM CDT Tue Sep 1 2020/
SHORT TERM (Today through Wednesday): Blast furnace conditions
will occur during this portion of the forecast. High pressure in
the middle layers of the atmosphere will continue to produce hot
temperatures with limited cloud cover today. As a result, a Heat
Advisory is in effect for all of Deep South Texas and the Rio
Grande Valley. Another Heat Advisory is likely on Wednesday with
similar synoptic conditions anticipated.
Adding to the heat misery will be strong winds, with high
pressure over the Gulf of Mexico interacting with low pressure
inland. As a result, a Wind Advisory is in effect for Cameron,
Willacy, and Kenedy counties today. The pressure gradient should
relax for Wednesday, negating the need for another Wind Advisory.
LONG TERM (Wednesday Night through Monday): A shift in the
weather pattern will occur during this portion of the forecast.
500 mb high pressure will initially dominate, leading to hot and
dry conditions on Thursday with another chance for a Heat
Advisory. Afterwards, and for the remainder of the forecast,
generally scattered showers and thunderstorms with corresponding
lower temperatures will prevail. This welcome shift in the
pattern will be due to a surge of deep tropical moisture from the
Bay of Campeche combining with 500 mb weakness that will develop
and persist over the entire Texas coastline and western Gulf of
Mexico.
MARINE (Today through Wednesday): Small Craft Advisories will
prevail during this portion of the forecast courtesy of high
pressure over the Gulf of Mexico interacting intensely with low
pressure over inland Mexico.
Wednesday Night through Monday: Improved marine conditions are
anticipated, with surface high pressure building farther west,
resulting in generally moderate winds and seas.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 95 82 95 82 / 0 0 0 0
BROWNSVILLE 99 82 97 82 / 0 0 0 0
HARLINGEN 101 81 100 81 / 0 0 0 0
MCALLEN 103 82 101 81 / 0 0 0 0
RIO GRANDE CITY 105 81 104 79 / 0 0 0 10
SOUTH PADRE ISLAND 90 84 89 84 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory from 10 AM this morning to 8 PM CDT this evening
for TXZ251-254>257-351.
Heat Advisory from noon today to 7 PM CDT this evening for
TXZ248>257-351-353.
GM...Small Craft Advisory until 10 PM CDT this evening for GMZ130-132-
135.
Small Craft Advisory until 7 AM CDT Wednesday for GMZ150-155-170-
175.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 95 82 95 82 / 0 0 0 0
BROWNSVILLE 99 82 97 82 / 0 0 0 0
HARLINGEN 101 81 100 81 / 0 0 0 0
MCALLEN 103 82 101 81 / 0 0 0 0
RIO GRANDE CITY 105 81 104 79 / 0 0 0 10
SOUTH PADRE ISLAND 90 84 89 84 / 0 0 0 0
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Aviation...MO (EWX)Hazardous Weather Outlook...UPDATED National Weather Service Brownsville TX 1014 AM CDT Tue Sep 1 2020 TXZ248>257-351-353-021515- Zapata-Jim Hogg-Brooks-Inland Kenedy-Starr-Southern Hidalgo- Inland Willacy-Inland Cameron-Coastal Willacy-Coastal Cameron- Coastal Kenedy-Northern Hidalgo- 1014 AM CDT Tue Sep 1 2020 This Hazardous Weather Outlook is for portions of Deep South Texas. .DAY ONE...Today and Tonight There is a Moderate Risk of rip currents at the beaches of South Padre Island and at Boca Chica Beach. A Heat Advisory is in effect for all of Deep South Texas and the Rio Grande Valley from 12 PM CDT to 7 PM CDT today. A Wind Advisory is in effect for Cameron, Willacy, and Kenedy counties from 10 AM CDT to 8 PM CDT today. .DAYS TWO THROUGH SEVEN...Wednesday through Monday An elevated risk of rip currents is possible at the local beaches Wednesday through Sunday. Additional Heat Advisories are possible within Deep South Texas and the Rio Grande Valley Wednesday and Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. GMZ130-132-135-150-155-170-175-021515- 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- Coastal waters from Port Mansfield to the Rio Grande out 20 nm- Coastal waters from Baffin Bay to Port Mansfield out 20 nm- Waters from Port Mansfield to the Rio Grande extending from 20 to 60 nm- Waters from Baffin Bay to Port Mansfield extending from 20 to 60 nm- 1014 AM CDT Tue Sep 1 2020 This Hazardous Weather Outlook is for portions of The Gulf of Mexico and The Laguna Madre. .DAY ONE...Today and Tonight A Small Craft Advisory is in effect for the Laguna Madre from 9 AM CDT to 10 PM CDT today. A Small Craft Advisory is in effect for the Gulf of Mexico waters from 0 to 60 nautical miles offshore until 7 AM CDT Wednesday. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Additional Small Craft Advisories are possible along the Lower Texas Coast on Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. Castillo/McGinnis
The national radar mosaic for the moment the first event began.
3 heat. Local standard time, as filed.
High afternoon temperatures combined with high relative humidity values to create heat indices that exceeded 111 degrees Fahrenheit for a couple of hours in Brownsville, Harlingen, and the surrounding areas.
High afternoon temperatures combined with high relative humidity values to create heat indices that exceeded 111 degrees Fahrenheit for a couple of hours in McAllen, Weslaco, and the surrounding areas.
High afternoon temperatures combined with high relative humidity values to create heat indices that exceeded 111 degrees Fahrenheit for a couple of hours in Zapata and the surrounding areas. Heat indices even briefly exceeded 116 degrees around 5 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2020Every state in 2020This day in weather historyWarnings in Texas, September 2020
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: 921756, 921757, 921758.