Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 601

May 12, 2021Cameron County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 12, 2021, 1:41 AM CDT for Cameron County, Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: May 12, 2021, 1:41 AM CDT (06:41 UTC)
Expired: May 12, 2021, 3:15 AM CDT
In force: 94 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 167

County Cameron County, TX

The radar

The Brownsville radar (KBRO), 50 km from the middle of the area, began a volume at 06:43 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

Brownsville Intl, TX (KBRO), launched 00:00Z, 6.7 hours before the alert went out and 53 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 2611 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 772 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

617 
ACUS11 KWNS 120641
SWOMCD
SPC MCD 120641 
TXZ000-120815-

Mesoscale Discussion 0601
NWS Storm Prediction Center Norman OK
0141 AM CDT Wed May 12 2021

Areas affected...Deep South Texas

Concerning...Severe Thunderstorm Watch 167...

Valid 120641Z - 120815Z

The severe weather threat for Severe Thunderstorm Watch 167
continues.

SUMMARY...Wind gusts up to 70 MPH will be possible over the next
hour or so across the Rio Grande Valley area of Deep South Texas.

DISCUSSION...Latest radar loop shows a well-organized cluster of
storms moving east-southeastward at 30 kt, now moving into southern
Cameron County.  A mesolow-type circulation is evident over
northeastern Hidalgo County, with the main surge of the convection
moving along the Rio Grande.  WSR-88D data from KBRO shows outflow
winds in excess of 60 kt at around 2000 feet ARL, with the
convection moving southeast at roughly 30 kt.  Given the
southeasterly low-level inflow, and mixed-layer CAPE near 2500 J/kg
across this region per objective analysis, this cluster should
remain well-organized until moving offshore over the next hour or
so.  As such, strong/potentially damaging winds will likely affect
the Brownsville area over the next 30 to 45 minutes.

..Goss/Guyer.. 05/12/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BRO...

LAT...LON   26399811 26459801 26479722 26099697 25839748 26029850
            26399811

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 8:02 PM CDT	Mesoscale Discussion	SPC	Brooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 8 more	118 min
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

Nearby

Mesoscale Discussions in Texas, 2021 Every 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.