A mesoscale convective system moved into South Central Texas from the northwest early in the morning of June 23. Storms produced heavy rain as they weakened with some minor flooding.
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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 EWX wrote it up.
A mesoscale convective system moved into South Central Texas from the northwest early in the morning of June 23. Storms produced heavy rain as they weakened with some minor flooding. An outflow boundary from this feature was the focus for convection later in the day. One storm was able to produce large hail.
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 23, 5:43 AM CST, 1 hour 25 minutes earlier.
Area Forecast Discussion National Weather Service Austin/San Antonio TX 643 AM CDT Tue Jun 23 2020 .AVIATION... /12Z TAFS/ Weakening line of storms moving into AUS is remaining just strong enough to make the prospects of it surviving into the midday hours uncertain. With this potentially impacting the SAT/SSF vcnty's, have gone ahead with a small tempo group in the late morning for some thunder. NAM/GFS is still accounted for in the grids and the TAFs, but this may need a downard revision if the storms hold together and keep the convective focus shifting southward with the leading edge. Also the NW flow pattern could lead to additional rounds of convection into tonight, but for now will assume MVFR cigs will be more likely than the chance of thunder. && .PREV DISCUSSION... /ISSUED 620 AM CDT Tue Jun 23 2020/ UPDATE... /POP AJDUST THIS MORNING/ Radar shows the weakening storm complex also slowing down in southward movement as was to be expected. However, the previous forecast update probably didn't include enough of a rain chance south of the Austin area in the 12Z-15Z timeframe. Thus this latest update is mainly cosmetic. PREV DISCUSSION... /ISSUED 440 AM CDT Tue Jun 23 2020/ UPDATE... Morning radar trends over West Central TX shows a slight uptick in storm intensity and this should make a more widspread coverage over the areas north of Austin from now through 15Z. Afternoon PoPs were not altered as much, but a slight shift was made toward a NAM/GFS blend which details higher PoPs from the Hondo/Uvalde area eastward to Taylor and La Grange. PREV DISCUSSION... /ISSUED 335 AM CDT Tue Jun 23 2020/ SHORT TERM (Today through Wednesday)... The unstable NW flow pattern aloft returns in full force today with an MCS about to move into the northern Hill Country between 10Z and 12Z. Severe winds have been reported from some of the cells, but the complex should be much weakened as it approaches the Austin metro area. Will still expect a few claps of thunder and perhaps some winds gusting above 30 mph as the leading edge remains quite healthy as of 3 AM. PoPs are on the conservative side and an update to refine the areas of higher rain chances and timing will likely be warranted as we get closer to shift change. High temperatures today will reflect a transition from the high pressure controlled areas of the SW and the MCS modified airmass over the NE counties. HREF stamps mostly show a system that breaks apart as it reaches the Austin area with a regeneration of activity along and south of I-10 and southeast of San Antonio. However, the NW flow pattern will likely keep the worked over atmosphere in motion and this leaves some uncertainty where convective initiation will be favored. Will keep the early morning package somewhat general, and refine later. While a cool pool of air and general cloudiness should limit storms from becoming too strong through midday, the late afternoon skies should break out again and lead to some strong storms and areas with surface based CAPES over 3500. With shear values generally below 40 knots a low end severe threat will exists into the evening, and the forecast area is painted with a MRGL risk. Going into late tonight, storms are not suggested to reform as an MCS in NW flow but rather scattered clusters clinging to leading MCV that upscales into a small synoptic low over SE TX and the Coastal Prairies. Should 06Z models and rapid refresh runs reinforce this trend, we may be able to lower some of the PoPs out west late tonight into Wednesday. Over the Coastal Prairies, some locally heavy downpours of 1-2 inch, isolated 3+ inch rains can't be ruled out. Initially our soils over the Coastal Prairies should be able to handle such rains. LONG TERM (Wednesday Night through Monday)... The problematic forecast continues during the beginning of the long- term period as confidence in the forecast each day remains low as many mesoscale features will likely play key roles on expected outcomes. On Wednesday night, southerly flow is expected to return after a brief stint of north winds Tuesday night and Wednesday. Models are in fairly decent agreement of only some scattered light to moderate activity occurring across the area with the return of the southerly flow and some weak ascent in the lower levels. The highest PoPs should be in the southern counties. On Thursday, the weak upper low is expected to remain over the area, with a continued chance of rain. The ECMWF is progging a high coverage and higher amounts of rain than what the GFS/NAM show. The ECMWF is much stronger with its southerly 850/700mb winds which likely leads to more ascent. Will hedge between the two for now and show 50-60 PoPs for the eastern areas with lesser PoPs for the western counties. Not much change is expected in the overall synoptic pattern through Friday. The ECMWF continues to show a stout low-level jet in the eastern counties and shows widespread rain with some heavy amounts Thursday night into Friday. In fact it appears to show the development of a stronger circulation indicative of an MCV across the area by Friday afternoon lasting into Friday night that develops because of the continued rainfall Thursday night. If this were to occur, portions of the CWA could see a fair amount of rain add up in the bucket. However, the GFS does not develop the amount of convection Thursday night and as a result, does not develop an MCV Friday. Again, the long-term forecast is highly dependent on the evolution of the forecast leading up to each time period. For what it's worth, the Canadian supports the GFS/NAM for the Thursday/Friday forecast in regards to the strength of the LLJ and subsequent precipitation amounts. Looking at run-total QPF forecasts, the GFS progs 1-3 inches from today through Friday night for areas along and east of the I35 corridor, while the ECMWF progs a 4-7 inch bullseye near the I35 corridor where it develops that persistent LLJ and subsequent MCV. Again, the ECMWF forecast needs to be viewed through a lens that understands that the model gives feedback to itself and develops features that are dependent on its forecast 12-24 hours prior verifying. Could it happen? Sure, but the confidence that it does is low. The official 5 day QPF forecast from WPC shows 1-3 inches for the eastern 2/3rds of the area and that is what we are going with as well. Then when you throw in the fact that Saharan Air Layer dust is set to arrive by the end of the work-week and this could be an inhibiting factor to rainfall amounts, this makes the forecast even less confident. Models are in fair agreement that the atmosphere will begin to dry out Saturday and this will continue into Monday. Will only forecast 20 PoPs for the eastern areas Saturday and Sunday. Temperatures should be in the upper 80s to lower 90s in the afternoon for most locations Thursday through Saturday but will slowly heat back up Sunday and Monday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 89 70 88 73 88 / 60 50 60 20 40 Austin Bergstrom Intl Airport 88 69 87 72 88 / 60 50 60 20 50 New Braunfels Muni Airport 91 72 87 73 88 / 60 60 60 30 50 Burnet Muni Airport 86 69 86 70 88 / 60 40 60 20 30 Del Rio Intl Airport 96 76 94 76 94 / 20 30 40 30 20 Georgetown Muni Airport 87 69 87 71 89 / 60 50 60 20 40 Hondo Muni Airport 94 74 91 73 91 / 60 50 60 40 40 San Marcos Muni Airport 89 71 88 72 88 / 60 60 60 30 50 La Grange - Fayette Regional 90 74 88 73 88 / 60 60 70 30 60 San Antonio Intl Airport 91 72 89 74 89 / 60 60 60 30 50 Stinson Muni Airport 93 73 89 75 88 / 60 60 60 40 50 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && Short-Term/Aviation...Oaks Long-Term...Hampshire
Hazardous Weather Outlook National Weather Service Austin/San Antonio TX 400 AM CDT Tue Jun 23 2020 TXZ171>173-183>194-202>209-217>225-228-241100- 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- 400 AM CDT Tue Jun 23 2020 This Hazardous Weather Outlook is for South-Central Texas.. .DAY ONE...Today And Tonight. Scattered to numerous thunderstorms are forecast over South Central Texas today and tonight. A few storms may contain some small hail and a potential for some damaging wind gusts. Some storm clusters may move over the same areas and lead to locally heavy downpours of 1 to 2 inches. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. There will remain a good chance of showers and thunderstorms across a much of South Central Texas Wednesday through Friday. Some pockets of heavy rainfall will be possible each day, and the cumulative rain chances could lead to localized flooding. .SPOTTER INFORMATION STATEMENT... Spotter are encouraged to use social media to provide reports of severe weather or flooding.
Special Weather Statement
National Weather Service Austin/San Antonio TX
508 AM CDT Tue Jun 23 2020
TXZ171-172-188-190-231130-
Blanco TX-Gillespie TX-Llano TX-Burnet TX-
508 AM CDT Tue Jun 23 2020
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN BLANCO...GILLESPIE...
LLANO AND BURNET COUNTIES UNTIL 630 AM CDT...
At 508 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Bend to near Streeter. Movement was
southeast at 40 mph.
Penny size hail and wind gusts up to 50 mph will be possible with
these storms.
Locations impacted include...
Fredericksburg, Burnet, Marble Falls, Kingsland, Llano, Bertram,
Round Mountain, Buchanan Dam, Gainesville, Granite Shoals, Horseshoe
Bay, Meadowlakes, Buchanan Lake Village, Stonewall, Highland Haven,
Castell, Field Creek, Inks Lake State Park, Watson and Bluffton.
LAT...LON 3090 9783 3078 9797 3050 9812 3049 9810
3045 9811 3014 9878 3014 9906 3043 9930
3047 9930 3050 9896 3092 9896 3092 9842
3094 9841 3096 9845 3103 9844 3103 9791
TIME...MOT...LOC 1008Z 328DEG 36KT 3117 9847 3081 9936
HAMPSHIREThe Ft Hood radar (KGRK), 35 km away, was scanning. The volume nearest the first event began at 13:05 UTC.
2 flood, 1 hail. Local standard time, as filed.
Thunderstorms produced heavy rain that caused minor flooding in Round Rock. Report was from mPING.
Thunderstorms produced heavy rain that caused minor street flooding around North Star Mall in northern San Antonio. Report was from mPING.
A thunderstorm produced ping pong ball size hail along Hwy 72 between Yorktown and Cuero.
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, June 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: 893621, 893624, 893625.