Alert archive / Texas / Mesoscale Discussions in 2020
Mesoscale Discussion 749
The Storm Prediction Center issued this mesoscale discussion at May 27, 2020, 7:11 PM CDT for 5 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 27, 2020, 7:11 PM CDT (00:11 UTC)
- Expired
- May 27, 2020, 9:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 232
Counties Bexar County, TX, Comal County, TX, Guadalupe County, TX, Kendall County, TX, Wilson County, TX
The radar
The Austin/San Antonio radar (KEWX), 50 km from the middle of the area, began a volume at 00:13 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Del Rio, TX (KDRT), launched 00:00Z, 0.2 hours before the alert went out and 225 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 937 J/kg
- Mixed-layer CIN
- -90 J/kg
- Mixed-layer LCL
- 2863 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 3 m²/s²
- 0-3 km storm-relative helicity
- 272 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.1
The text
As transmitted.
013 ACUS11 KWNS 280011 SWOMCD SPC MCD 280011 TXZ000-280215- Mesoscale Discussion 0749 NWS Storm Prediction Center Norman OK 0711 PM CDT Wed May 27 2020 Areas affected...the San Antonio/New Braunfels area Concerning...Severe Thunderstorm Watch 232... Valid 280011Z - 280215Z The severe weather threat for Severe Thunderstorm Watch 232 continues. SUMMARY...A severe storm has the potential to strengthen further this evening as it travels southeast toward the San Antonio area. Very large hail is likely, and damaging winds are also possible. DISCUSSION...A supercell producing large hail over Gillespie county TX will likely persist as it travels southeastward across the San Antonio area, aided by strong deep-layer shear. The storm is currently severe, but may strengthen further as it encounters stronger instability to the south. Meanwhile, an outflow boundary about 30 miles northeast of San Antonio continues to drift southwestward, and may provide added lift should the storm intersect. Any upscale growth/bowing may result in significant wind gusts. While hodographs are primarily straight-line, a brief tornado cannot be ruled out along the boundary. ..Jewell.. 05/28/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EWX... LAT...LON 29909906 30259875 29599787 29149788 29189864 29909906
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 9:35 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bexar, DeWitt, Frio, Gonzales and 5 more | 115 min |
| May 28, 1:44 PM CDT | Mesoscale Discussion | SPC | Bandera, Bexar, Concho, Crockett, Edwards, Gillespie and 19 more | 2 hr |
| May 28, 2:26 PM CDT | Severe Thunderstorm Watch | SPC | Atascosa, Bandera, Bexar, Blanco, Comal, Dimmit and 16 more | 5 hr |
| May 28, 3:01 PM CDT | Mesoscale Discussion | SPC | Galveston | 119 min |
| May 28, 6:29 PM CDT | Mesoscale Discussion | SPC | Aransas, Atascosa, Bee, Caldwell, Calhoun, Colorado and 22 more | 2 hr |
Nearby
Mesoscale Discussions in Texas, 2020Every mesoscale discussion in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.