Alert archive / Texas / Mesoscale Discussions in 2018

Mesoscale Discussion 798

June 19, 20184 counties in Oklahoma; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 19, 2018, 7:40 PM CDT for 4 counties in Oklahoma; 7 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 19, 2018, 7:40 PM CDT (00:40 UTC)
Expired: Jun 19, 2018, 9:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Beaver County, OK, Ellis County, OK, Roger Mills County, OK, Texas County, OK, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Ochiltree County, TX, Roberts County, TX, Sherman County, TX

The radar

The Amarillo radar (KAMA), 133 km from the middle of the area, began a volume at 00:43 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 194Jun 19, 10:05 PM CDT

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 0.7 hours before the alert went out and 133 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: 1503 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1903 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

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
Jun 19, 9:33 PM CDT	Mesoscale Discussion	SPC	Beaver, Harper, Texas	117 min
Jun 19, 10:07 PM CDT	Severe Thunderstorm Watch	SPC	Beaver, Ellis, Harper, Woods, Woodward	5 hr
Jun 19, 11:41 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beaver, Ellis, Harper, Texas, Woods and 1 more	2 hr
Jun 20, 2:12 AM CDT	Mesoscale Discussion	SPC	Beckham, Ellis, Roger Mills	2 hr

Nearby

Mesoscale Discussions in Texas, 2018 Mesoscale Discussions in Oklahoma, 2018 Every mesoscale discussion in 2018

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.