Alert archive / Mississippi / Mesoscale Discussions in 2017

Mesoscale Discussion 409

April 2, 201715 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2017, 5:06 PM CDT for 15 counties in Mississippi. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Apr 2, 2017, 5:06 PM CDT (22:06 UTC)
Expired: Apr 2, 2017, 6:30 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Bolivar County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Tallahatchie County, MS, Union County, MS, Yalobusha County, MS

The radar

The Memphis radar (KNQA), 129 km from the middle of the area, began a volume at 22:08 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 112Apr 2, 5:20 PM CDT

The nearest sounding before it

Little Rock, AR (KBYH), launched 12:00Z, 10.1 hours before the alert went out and 72 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: 1438 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 213 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
Apr 2, 12:49 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Franklin, Hinds and 7 more	116 min
Apr 2, 1:34 PM CDT	Tornado Watch PDS	SPC	Adams, Bolivar, Claiborne, Humphreys, Issaquena, Jefferson and 5 more	7 hr
Apr 2, 3:08 PM CDT	Mesoscale Discussion	SPC	Amite, Pike, Walthall	3 hr
Apr 2, 3:31 PM CDT	Mesoscale Discussion	SPC	Carroll, Holmes, Humphreys, Leflore, Montgomery, Sunflower and 1 more	29 min
Apr 2, 4:52 PM CDT	Tornado Watch	SPC	Adams, Amite, Attala, Carroll, Choctaw, Claiborne and 39 more	9 hr
Apr 2, 5:26 PM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Chickasaw, Coahoma, Itawamba, Lafayette, Lee and 7 more	3 hr

Nearby

Mesoscale Discussions in Mississippi, 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.