Excessive Heat in Texas, June 14 to 21, 2023

Name: Excessive Heat in Texas, June 14 to 21, 2023
Start: 2023-06-14T13:00
End: 2023-06-21T21:00
Location: Texas

June 14 to 21, 2023 · NWS EWX · 33 events in 33 counties and zones

Strong high pressure settled over South Central Texas, and temperatures and heat indices soared. The heat wave started on the 14th in Atascosa County where the heat index reached 113.

Where it happened

Every event with a place to put it; 33 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 33

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.

What happened

The episode as NWS EWX wrote it up.

Strong high pressure settled over South Central Texas, and temperatures and heat indices soared. The heat wave started on the 14th in Atascosa County where the heat index reached 113. The excessive heat expanded over the next several days until it reached its peak on the 21st when all counties reached excessive heat criteria. A number of record highs were set during this period. Austin Bergstrom reached 102 on the 21st; Austin Camp Mabry 103 on the 16th and 106 on the 18th; San Antonio 105 on both the 19th and 20th. Del Rio set new record highs every day from the 18th until the 28th including a new all time record high of 115 on the 21st. We also saw record warm lows. Austin Bergstrom had records each day the 14th through the 16th; Austin Camp Mabry set a new monthly record of 82 on the 15th and reached daily records on the 14th, 19th, and 20th; San Antonio tied the monthly record of 80 each day the 14th through the 17th; Del Rio set a new monthly record of 85 on the 17th and again on the 22nd which occurred during a streak of daily records each day from the 13th through the 25th. Peak heat index values included 122 degrees at Pleasanton on the 21st, 125 at New Braunfels on the 21st, and 120 at San Marcos on the 21st.

What forecasters said that day

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 Austin/San Antonio, TX wrote its last area forecast discussion before the first event at Jun 14, 12:00 PM CST, 1 hour earlier.

Area forecast discussion, Jun 14, 12:00 PM CST, 1 hour before

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
100 PM CDT Wed Jun 14 2023

...New AVIATION...

.SHORT TERM...
(Today through Thursday)
Issued at 141 AM CDT Wed Jun 14 2023

Cloud cover held on for a long time yesterday which kept
temperatures down, but because of that dewpoints stayed elevated and
heat index values remained near advisory levels across much of the
area. Low clouds are already in place across much of the area
overnight with high clouds also streaming overhead. Because of this,
today should be similar to that of yesterday for the most part. The
NBM remains much too warm for day time highs while the HRRR and
other short-term models continue to verify best. Stuck closer to
those models and will show highs ranging from the middle 90s in the
east, upper 90s along the I35 corridor, and into the 100-103 degree
range out west. With the slightly lower temperatures expected,
dewpoints should remain in the middle 70s for much of the day. This
should lead to afternoon heat index values near 108 degrees. A Heat
Advisory has already been issued for today for the southwestern
counties and for points along and east of the I35 corridor and this
area still looks good and will make no areal changes. There is about
a 10 percent chance of a stray shower or storm in the extreme
northern CWA today, but chances are much too low to mention in the
forecast.

For tonight, lows will remain warm, in the middle to upper 70s for
most locations. Should finally see slightly higher temperatures on
Thursday. Models are consistently showing warming at 850 mb and this
should lead to less morning stratus cover and then lead to more
warming at the surface in the afternoon. Highs Thursday should be
about 2-4 degrees warmer than today. However with that, dewpoints
should mix out a bit better and afternoon heat index value should be
in the 108-112 range for the areas already in the Heat Advisory for
today. Went ahead and extended the advisory into tomorrow to account
for this. A couple more short-term models show some isolated
convection tomorrow afternoon. Will keep the forecast dry for now,
but this is something to monitor.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 141 AM CDT Wed Jun 14 2023

Continued hot and humid conditions are expected through the end of
the week and into early next week as mid-level ridging slowly
amplifies over south-central Texas. Not much more can be said as has
been said over the last several days as there aren't many other ways
to describe this heat. One thing to note: The NBM has been running a
good 3-5 degrees too warm as it continues to mix things out way too
quickly in the afternoon. Surface moisture remains persistent due in
part to moist flow off the Gulf of Mexico as well as remnant soil
moisture from our mostly above normal spring rainy season. Even
after leaning closer to the NBM 25th percentile for Max and Min T,
it's still going to be gross. Afternoon highs will slowly but surely
start to climb into the 100-105 range area wide by late in the
weekend as soil moisture continues to dry out and we mix out a bit
more each day. Factoring in dewpoints in the upper 60s to mid 70s,
it will feel like between 105-113 through the next week.

Turning our attention to something other than heat, the long range
ECM and GFS Ensembles do indicate the 500mb ridging may start to
slide further west and center over the Permian Basin/Southwest Texas
by the middle to end of next week, resulting in north to
northwesterly flow over the CWA. This could result in a return to a
somewhat active pattern with several impulses riding around the
ridge. We'll see how things play out, but if we can get back into a
more active pattern, hopefully we can cool things off just a tad.

&&

.AVIATION...
(18Z TAFS)
Issued at 1254 PM CDT Wed Jun 14 2023

MVFR ceilings are lingering in the San Antonio area, but should lift
to VFR within the next hour or so. AUS and DRT are VFR. Once ceilings
improve in San Antonio, all terminals will be VFR through the
afternoon and evening. MVFR ceilings will redevelop overnight in
Austin and San Antonio. Guidance keeps DRT VFR and we have gone with
this solution. There is a low chance for MVFR ceilings early Thursday
morning. VFR conditions will return to all airports by late morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              78 101  76 103 /   0  10   0   0
Austin Bergstrom Intl Airport  77  99  74 102 /   0  10   0   0
New Braunfels Muni Airport     77 100  75 102 /   0   0   0   0
Burnet Muni Airport            76 100  75 103 /   0  10   0   0
Del Rio Intl Airport           79 105  80 107 /   0   0   0   0
Georgetown Muni Airport        76 100  74 103 /   0  10   0   0
Hondo Muni Airport             77 102  76 104 /   0   0   0   0
San Marcos Muni Airport        77 100  73 103 /   0   0   0   0
La Grange - Fayette Regional   78  98  74  99 /   0   0   0   0
San Antonio Intl Airport       78 101  77 102 /   0   0   0   0
Stinson Muni Airport           79 101  77 102 /   0   0   0   0

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT Thursday for Atascosa-Bastrop-Bexar-
Caldwell-Comal-De Witt-Dimmit-Fayette-Frio-Gonzales-Guadalupe-Hays-
Karnes-Lavaca-Lee-Maverick-Medina-Travis-Uvalde-Williamson-Wilson-
Zavala.

&&

Short-Term...29
Long-Term...MMM
Aviation...05

Hazardous weather outlook, Jun 14, 10:45 AM CST, 2 hours 15 minutes before

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
1145 AM CDT Wed Jun 14 2023

TXZ171>173-183>194-202>209-217>225-228-151645-
Llano-Burnet-Williamson-Val Verde-Edwards-Real-Kerr-Bandera-
Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee-Kinney-Uvalde-
Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Maverick-Zavala-
Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-Dimmit-
1145 AM CDT Wed Jun 14 2023

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...This Afternoon And Tonight.

A Heat Advisory remains in effect this afternoon and early
evening for much of the Rio Grande Plains, I-35 corridor, and the
Coastal Plains as heat indices up to 112 degrees will be possible.

There are slight chances for isolated thunderstorms over portions
of Hill Country and the I-35 Corridor later this afternoon and
evening. Any storms that develop would have the potential to
become severe with large hail and damaging winds being the main
hazards. The Storm Prediction Center includes areas primarily
north and east of Austin in a marginal (level 1 out of 5) risk
for severe weather in light of this potential.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Above average temperatures will continue through the next week,
and combined with humidity across the region, residents will need
to take precautions to guard against heat illness during this
time. Heat Advisories and perhaps Excessive Heat Warnings will be
possible for portions of the area on many days through this
period.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

33 excessive heat. Local standard time, as filed.

Excessive Heat, Atascosa

When: June 14, 1:00 PM CST to June 21, 9:00 PM CST
Where: Atascosa forecast zone
Reported by: AWOS
Coordinates: 28.894, -98.527 (the zone’s center; the record gives no point)

Excessive Heat, Bastrop

When: June 15, 1:00 PM CST to June 21, 1:00 PM CST
Where: Bastrop forecast zone
Reported by: AWOS
Coordinates: 30.104, -97.312 (the zone’s center; the record gives no point)

Excessive Heat, Bexar

When: June 15, 1:00 PM CST to June 21, 1:00 PM CST
Where: Bexar forecast zone
Reported by: AWOS
Coordinates: 29.449, -98.520 (the zone’s center; the record gives no point)

Excessive Heat, Blanco

When: June 15, 1:00 PM CST to June 21, 1:00 PM CST
Where: Blanco forecast zone
Reported by: AWOS
Coordinates: 30.266, -98.400 (the zone’s center; the record gives no point)

Excessive Heat, Caldwell

When: June 15, 1:00 PM CST to June 21, 1:00 PM CST
Where: Caldwell forecast zone
Reported by: AWOS
Coordinates: 29.837, -97.620 (the zone’s center; the record gives no point)

Excessive Heat, Comal

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Comal forecast zone
Reported by: AWOS
Coordinates: 29.808, -98.278 (the zone’s center; the record gives no point)

Excessive Heat, Dimmit

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Dimmit forecast zone
Reported by: AWOS
Coordinates: 28.423, -99.757 (the zone’s center; the record gives no point)

Excessive Heat, Edwards

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Edwards forecast zone
Reported by: AWOS
Coordinates: 29.983, -100.305 (the zone’s center; the record gives no point)

Excessive Heat, Fayette

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Fayette forecast zone
Reported by: AWOS
Coordinates: 29.877, -96.920 (the zone’s center; the record gives no point)

Excessive Heat, Frio

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Frio forecast zone
Reported by: AWOS
Coordinates: 28.868, -99.108 (the zone’s center; the record gives no point)

Excessive Heat, Gillespie

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Gillespie forecast zone
Reported by: AWOS
Coordinates: 30.318, -98.946 (the zone’s center; the record gives no point)

Excessive Heat, Gonzales

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Gonzales forecast zone
Reported by: AWOS
Coordinates: 29.457, -97.492 (the zone’s center; the record gives no point)

Excessive Heat, Guadalupe

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Guadalupe forecast zone
Reported by: AWOS
Coordinates: 29.583, -97.949 (the zone’s center; the record gives no point)

Excessive Heat, Hays

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Hays forecast zone
Reported by: AWOS
Coordinates: 30.058, -98.031 (the zone’s center; the record gives no point)

Excessive Heat, Karnes

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Karnes forecast zone
Reported by: AWOS
Coordinates: 28.906, -97.859 (the zone’s center; the record gives no point)

Excessive Heat, Kendall

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Kendall forecast zone
Reported by: AWOS
Coordinates: 29.945, -98.712 (the zone’s center; the record gives no point)

Excessive Heat, Kerr

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Kerr forecast zone
Reported by: AWOS
Coordinates: 30.062, -99.350 (the zone’s center; the record gives no point)

Excessive Heat, Kinney

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Kinney forecast zone
Reported by: AWOS
Coordinates: 29.350, -100.418 (the zone’s center; the record gives no point)

Excessive Heat, Lavaca

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Lavaca forecast zone
Reported by: AWOS
Coordinates: 29.384, -96.930 (the zone’s center; the record gives no point)

Excessive Heat, Lee

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Lee forecast zone
Reported by: AWOS
Coordinates: 30.311, -96.966 (the zone’s center; the record gives no point)

Excessive Heat, Llano

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Llano forecast zone
Reported by: AWOS
Coordinates: 30.706, -98.684 (the zone’s center; the record gives no point)

Excessive Heat, Maverick

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Maverick forecast zone
Reported by: AWOS
Coordinates: 28.743, -100.314 (the zone’s center; the record gives no point)

Excessive Heat, Medina

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Medina forecast zone
Reported by: AWOS
Coordinates: 29.356, -99.110 (the zone’s center; the record gives no point)

Excessive Heat, Real

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Real forecast zone
Reported by: AWOS
Coordinates: 29.832, -99.822 (the zone’s center; the record gives no point)

Excessive Heat, Travis

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Travis forecast zone
Reported by: AWOS
Coordinates: 30.335, -97.782 (the zone’s center; the record gives no point)

Excessive Heat, Uvalde

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Uvalde forecast zone
Reported by: AWOS
Coordinates: 29.357, -99.762 (the zone’s center; the record gives no point)

Excessive Heat, Val Verde

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Val Verde forecast zone
Reported by: AWOS
Coordinates: 29.893, -101.152 (the zone’s center; the record gives no point)

Excessive Heat, Williamson

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Williamson forecast zone
Reported by: AWOS
Coordinates: 30.648, -97.601 (the zone’s center; the record gives no point)

Excessive Heat, Wilson

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Wilson forecast zone
Reported by: AWOS
Coordinates: 29.174, -98.087 (the zone’s center; the record gives no point)

Excessive Heat, Zavala

When: June 15, 1:00 PM CST to June 21, 9:00 PM CST
Where: Zavala forecast zone
Reported by: AWOS
Coordinates: 28.866, -99.761 (the zone’s center; the record gives no point)

Excessive Heat, Bandera

When: June 16, 1:00 PM CST to June 21, 9:00 PM CST
Where: Bandera forecast zone
Reported by: AWOS
Coordinates: 29.747, -99.246 (the zone’s center; the record gives no point)

Excessive Heat, Burnet

When: June 16, 1:00 PM CST
Where: Burnet forecast zone
Reported by: AWOS
Coordinates: 30.788, -98.182 (the zone’s center; the record gives no point)

Excessive Heat, De Witt

When: June 17, 1:00 PM CST to June 21, 9:00 PM CST
Where: De Witt forecast zone
Reported by: AWOS
Coordinates: 29.082, -97.357 (the zone’s center; the record gives no point)

What these are

Excessive Heat: Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Texas in 2023 Every state in 2023 This day in weather history Warnings in Texas, June 2023

Sources

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: 1115243, 1115246, 1115248, 1115249, 1115251, 1115253, 1115256, 1115257, 1115258, 1115259, 1115260, 1115261, 1115262, 1115263, 1115265, 1115266, 1115267, 1115268, 1115269, 1115270, 1115271, 1115272, 1115273, 1115274, 1115275, 1115276, 1115277, 1115278, 1115279, 1115280, 1115245, 1115250, 1115255.