Alert archive / Mississippi / Mesoscale Discussions in 2013
Mesoscale Discussion 764
The Storm Prediction Center issued this mesoscale discussion at May 21, 2013, 7:39 PM CDT for 14 parishes in Louisiana; 23 counties in Mississippi. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 21, 2013, 7:39 PM CDT (00:39 UTC)
- Expired
- May 21, 2013, 9:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 37 counties
Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Franklin Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Rapides Parish, LA, Richland Parish, LA, Tensas Parish, LA, Vernon Parish, LA, Adams County, MS, Attala County, MS, Choctaw County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Issaquena County, MS, Jefferson County, MS, Kemper County, MS, Leake County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Warren County, MS, Winston County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 82 km from the middle of the area, began a volume at 00:41 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.
The nearest sounding before it
Jackson, MS (KJAN), launched 00:00Z, 0.7 hours before the alert went out and 74 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.
- Mixed-layer CAPE
- 1286 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 1432 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 21, 9:01 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Avoyelles, Beauregard, Catahoula, Concordia, East Carroll and 9 more | 5 hr |
| May 21, 9:22 PM CDT | Mesoscale Discussion | SPC | Calhoun, Chickasaw, Grenada, Itawamba, Lee, Monroe and 5 more | 23 min |
| May 21, 11:41 PM CDT | Mesoscale Discussion | SPC | Adams, Attala, Choctaw, Claiborne, Clay, Copiah and 20 more | 64 min |
Nearby
Mesoscale Discussions in Mississippi, 2013Mesoscale Discussions in Louisiana, 2013Every mesoscale discussion in 2013
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.