Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 598
The Storm Prediction Center issued this mesoscale discussion at May 11, 2021, 8:02 PM CDT for 14 counties in Texas. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- May 11, 2021, 8:02 PM CDT (01:02 UTC)
- Expired
- May 11, 2021, 10:00 PM CDT
- In force
- 118 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 165
Counties Brooks County, TX, Cameron County, TX, Duval County, TX, Hidalgo County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Nueces County, TX, San Patricio County, TX, Starr County, TX, Webb County, TX, Willacy County, TX, Zapata County, TX
The radar
The Corpus Christi radar (KCRP), 106 km from the middle of the area, began a volume at 01:03 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Corpus Christi, TX (KCRP), launched 00:00Z, 1.0 hours before the alert went out and 114 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
- 2320 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 854 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 45 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 4.2
The text
As transmitted.
593
ACUS11 KWNS 120102
SWOMCD
SPC MCD 120102
TXZ000-120300-
Mesoscale Discussion 0598
NWS Storm Prediction Center Norman OK
0802 PM CDT Tue May 11 2021
Areas affected...South Texas
Concerning...Severe Thunderstorm Watch 165...
Valid 120102Z - 120300Z
The severe weather threat for Severe Thunderstorm Watch 165
continues.
SUMMARY...A severe threat is expected to develop to the south of WW
165 over the next few hours. Wind damage and large hail will be the
primary threats. New weather watch issuance will likely be needed as
the storms move toward the south edge of the ongoing watch.
DISCUSSION...The latest radar imagery from San Antonio shows a
cluster of severe storms located to the north and northeast of
Laredo. These storms are moving southward into a moderately unstable
airmass, with the RAP estimating MLCAPE in the 2000 to 3000 J/kg
range. The WSR-88D VWP out of Corpus Christi shows about 40 kt of
0-6 km shear with flow at 1 km above ground level near 25 knot.
Low-level flow is forecast to gradually increase across south Texas
this evening. This combined with the instability will help to
maintain cell intensity within the ongoing severe storm cluster.
Wind damage and isolated large hail is expected to impact south
Texas later this evening, and weather watch issuance will likely be
needed.
..Broyles.. 05/12/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CRP...BRO...
LAT...LON 28159728 27939870 27829946 27559957 26909936 26339902
26069857 25969733 25959711 26579722 27089733 28159728SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 8:33 PM CDT | Mesoscale Discussion | SPC | Jefferson, Orange | 87 min |
| May 11, 8:34 PM CDT | Severe Thunderstorm Watch | SPC | Brooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Kleberg and 5 more | 7 hr |
| May 11, 10:47 PM CDT | Mesoscale Discussion | SPC | Brooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 8 more | 118 min |
| May 12, 1:41 AM CDT | Mesoscale Discussion | SPC | Cameron | 94 min |
Nearby
Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021
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.