Alert archive / Louisiana / Mesoscale Discussions in 2018

Mesoscale Discussion 528

May 26, 2018Ashley County, Chicot County, Arkansas; 18 parishes in Louisiana; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 26, 2018, 11:58 AM CDT for Ashley County, Chicot County, Arkansas; 18 parishes in Louisiana; 5 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 26, 2018, 11:58 AM CDT (16:58 UTC)
Expired: May 26, 2018, 2:30 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 25 counties

Ashley County, AR, Chicot County, AR, Allen Parish, LA, Beauregard Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Richland Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Jasper County, TX, Newton County, TX, Sabine County, TX, San Augustine County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 69 km from the middle of the area, began a volume at 16:58 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

Shreveport, LA (KBAD), launched 12:00Z, 5.0 hours before the alert went out and 119 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 0 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 94 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
May 25, 8:53 PM CDT	Mesoscale Discussion	SPC	Burnet, Gillespie, Kimble, Lampasas, Llano, McCulloch and 3 more	67 min
May 25, 9:17 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Childress, Clay, Collingsworth, Foard and 8 more	88 min

Nearby

Mesoscale Discussions in Louisiana, 2018 Mesoscale Discussions in Texas, 2018 Mesoscale Discussions in Arkansas, 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.