Alert archive / Mississippi / Mesoscale Discussions in 2012
Mesoscale Discussion 1842
The Storm Prediction Center issued this mesoscale discussion at Aug 30, 2012, 9:05 PM CDT for Washington Parish, Louisiana; 57 counties in Mississippi. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- Aug 30, 2012, 9:05 PM CDT (02:05 UTC)
- Expired
- Aug 30, 2012, 10:00 PM CDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
All 58 counties
Washington Parish, LA, Adams County, MS, Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Grenada County, MS, Hancock County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jackson County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Sunflower County, MS, Walthall County, MS, Warren County, MS, Washington County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 27 km from the middle of the area, began a volume at 02:08 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.
The nearest sounding before it
Jackson, MS (KJAN), launched 00:00Z, 2.1 hours before the alert went out and 30 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
- 42 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 796 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 303 m²/s²
- 0-3 km storm-relative helicity
- 319 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 |
|---|---|---|---|---|
| Aug 31, 4:14 AM CDT | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Calcasieu, Caldwell, Catahoula and 6 more | 91 min |
| Aug 30, 7:15 PM CDT | Mesoscale Discussion | SPC | Attala, Bolivar, Carroll, Choctaw, Claiborne, Clarke and 36 more | 90 min |
| Aug 30, 9:44 PM CDT | Tornado Watch | SPC | Attala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 47 more | 5 hr |
Nearby
Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Louisiana, 2012Every mesoscale discussion in 2012
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.