Alert archive / Texas / Mesoscale Discussions in 2020

Mesoscale Discussion 495

April 28, 2020Jim Hogg County, Starr County, Zapata County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2020, 9:04 PM CDT for Jim Hogg County, Starr County, Zapata County, Texas. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Apr 28, 2020, 9:04 PM CDT (02:04 UTC)
Expired: Apr 28, 2020, 11:00 PM CDT
In force: 116 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Jim Hogg County, TX, Starr County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 188 km from the middle of the area, began a volume at 02:05 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

Corpus Christi, TX (KCRP), launched 00:00Z, 2.1 hours before the alert went out and 199 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: 3695 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 928 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 2.3
Supercell composite: 11.6

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 28, 8:06 PM CDT	Mesoscale Discussion	SPC	Anderson, Bosque, Bowie, Camp, Cass, Cherokee and 44 more	54 min
Apr 28, 8:25 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Angelina, Bell, Bosque, Bowie, Brazos and 69 more	9 hr
Apr 28, 10:08 PM CDT	Mesoscale Discussion	SPC	Collin, Cooke, Dallas, Delta, Denton, Fannin and 11 more	97 min
Apr 29, 1:56 AM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Bell, Bosque, Brazos, Burleson and 28 more	2 hr
Apr 29, 2:40 AM CDT	Severe Thunderstorm Watch	SPC	Austin, Bastrop, Brazoria, Burnet, Caldwell, Chambers and 25 more	6 hr
Apr 29, 5:05 AM CDT	Mesoscale Discussion	SPC	Austin, Bastrop, Blanco, Brazoria, Caldwell, Calhoun and 25 more	115 min

Nearby

Mesoscale Discussions in Texas, 2020 Every 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.