Alert archive / Texas / Mesoscale Discussions in 2018

Mesoscale Discussion 227

April 6, 201815 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2018, 9:22 PM CDT for 15 counties in Texas. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Apr 6, 2018, 9:22 PM CDT (02:22 UTC)
Expired: Apr 6, 2018, 10:45 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center

Counties Anderson County, TX, Falls County, TX, Freestone County, TX, Henderson County, TX, Houston County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Navarro County, TX, Polk County, TX, Robertson County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX

The radar

The Ft Hood radar (KGRK), 137 km from the middle of the area, began a volume at 02:24 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 00:00Z, 2.4 hours before the alert went out and 209 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: 690 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 1896 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

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 6, 8:12 PM CDT	Mesoscale Discussion	SPC	Jasper, Newton, Orange	63 min
Apr 6, 8:53 PM CDT	Severe Thunderstorm Watch	SPC	Hardin, Jasper, Jefferson, Newton, Orange, Tyler	10 hr
Apr 6, 10:57 PM CDT	Mesoscale Discussion	SPC	Jasper, Jefferson, Newton, Orange	93 min
Apr 7, 1:37 AM CDT	Mesoscale Discussion	SPC	Orange	83 min

Nearby

Mesoscale Discussions in Texas, 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.