Alert archive / Mississippi / Mesoscale Discussions in 2017

Mesoscale Discussion 1603

August 30, 2017Choctaw County, Sumter County, Washington County, Alabama; East Carroll Parish, Madison Parish, Louisiana; 28 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Aug 30, 2017, 2:55 PM CDT for Choctaw County, Sumter County, Washington County, Alabama; East Carroll Parish, Madison Parish, Louisiana; 28 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 30, 2017, 2:55 PM CDT (19:55 UTC)
Expired: Aug 30, 2017, 5:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 33 counties

Choctaw County, AL, Sumter County, AL, Washington County, AL, East Carroll Parish, LA, Madison Parish, LA, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Greene County, MS, Hinds County, MS, Issaquena County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Perry County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Warren County, MS, Wayne County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 8 km from the middle of the area, began a volume at 19:56 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

Jackson, MS (KJAN), launched 12:00Z, 7.9 hours before the alert went out and 18 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: 273 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 523 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 235 m²/s²
0-3 km storm-relative helicity: 218 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.0

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
Aug 30, 1:00 AM CDT	Mesoscale Discussion	SPC	Baldwin, Mobile	90 min
Aug 30, 6:57 AM CDT	Mesoscale Discussion	SPC	Baldwin	2 hr
Aug 30, 10:22 AM CDT	Tornado Watch	SPC	Baldwin, Choctaw, Clarke, Mobile, Washington	8 hr
Aug 30, 12:10 PM CDT	Mesoscale Discussion	SPC	Barbour, Dale, Geneva, Henry, Houston, Russell	2 hr
Aug 30, 12:36 PM CDT	Mesoscale Discussion	SPC	Baldwin, Clarke, Mobile, Washington	114 min
Aug 30, 9:51 AM CDT	Mesoscale Discussion	SPC	Catahoula, Concordia, East Feliciana, Franklin, LaSalle, Saint Helena and 4 more	114 min
Aug 30, 5:50 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Catahoula, Concordia, East Carroll, East Feliciana, Franklin and 8 more	55 min

Nearby

Mesoscale Discussions in Mississippi, 2017 Mesoscale Discussions in Alabama, 2017 Mesoscale Discussions in Louisiana, 2017 Every mesoscale discussion in 2017

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.