Alert archive / Mississippi / Mesoscale Discussions in 2011

Mesoscale Discussion 1864

August 5, 2011Monroe County, Phillips County, Arkansas; 17 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Aug 5, 2011, 12:06 PM CDT for Monroe County, Phillips County, Arkansas; 17 counties in Mississippi. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Aug 5, 2011, 12:06 PM CDT (17:06 UTC)
Expired: Aug 5, 2011, 1:00 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center

Counties Monroe County, AR, Phillips County, AR, Calhoun County, MS, Chickasaw County, MS, Clay County, MS, Coahoma County, MS, Grenada County, MS, Lafayette County, MS, Lee County, MS, Monroe County, MS, Montgomery County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Tallahatchie County, MS, Tunica County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS

The radar

The Memphis radar (KNQA), 124 km from the middle of the area, began a volume at 17:08 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 nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 5.1 hours before the alert went out and 67 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: 1935 J/kg
Mixed-layer CIN: -196 J/kg
Mixed-layer LCL: 1390 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: 13 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 4, 7:18 PM CDT	Mesoscale Discussion	SPC	Garland, Howard, Montgomery, Pike, Polk, Scott and 1 more	57 min
Aug 4, 8:52 PM CDT	Mesoscale Discussion	SPC	Garland, Howard, Montgomery, Pike, Polk, Scott and 1 more	53 min

Nearby

Mesoscale Discussions in Mississippi, 2011 Mesoscale Discussions in Arkansas, 2011 Every mesoscale discussion in 2011

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.