Alert archive / Texas / Mesoscale Discussions in 2018

Mesoscale Discussion 77

February 20, 2018Carter County, Jefferson County, Love County, Oklahoma; 16 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 20, 2018, 11:11 AM CST for Carter County, Jefferson County, Love County, Oklahoma; 16 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Feb 20, 2018, 11:11 AM CST (17:11 UTC)
Expired: Feb 20, 2018, 12:45 PM CST
In force: 94 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Carter County, OK, Jefferson County, OK, Love County, OK, Archer County, TX, Baylor County, TX, Callahan County, TX, Clay County, TX, Cooke County, TX, Jack County, TX, Jones County, TX, Montague County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 88 km from the middle of the area, began a volume at 17:13 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

Fort Worth, TX (KFWD), launched 12:00Z, 5.2 hours before the alert went out and 146 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 850 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

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
Feb 20, 4:21 AM CST	Mesoscale Discussion	SPC	Alfalfa, Woods, Woodward	3 hr
Feb 20, 8:52 AM CST	Mesoscale Discussion	SPC	Carter, Johnston, Love, Marshall	113 min
Feb 20, 9:40 AM CST	Mesoscale Discussion	SPC	Cleveland, Creek, Grady, Lincoln, Logan, McClain and 6 more	4 hr
Feb 19, 10:07 PM CST	Mesoscale Discussion	SPC	Bandera, Brown, Coleman, Comanche, Concho, Edwards and 13 more	53 min

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.