Alert archive / Mississippi / Mesoscale Discussions in 2014

Mesoscale Discussion 424

April 27, 20149 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2014, 4:01 PM CDT for 9 counties in Mississippi. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Apr 27, 2014, 4:01 PM CDT (21:01 UTC)
Expired: Apr 27, 2014, 5:30 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Carroll County, MS, Choctaw County, MS, Coahoma County, MS, Grenada County, MS, Leflore County, MS, Montgomery County, MS, Oktibbeha County, MS, Tallahatchie County, MS, Webster County, MS

The radar

The Columbus AFB radar (KGWX), 153 km from the middle of the area, began a volume at 21:03 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.

Tornado Watch 101Apr 27, 5:30 PM CDT

The nearest sounding before it

Little Rock, AR (KBYH), launched 12:00Z, 9.0 hours before the alert went out and 116 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: 644 J/kg
Mixed-layer CIN: -205 J/kg
Mixed-layer LCL: 1166 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 46 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

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
Apr 27, 6:05 AM CDT	Mesoscale Discussion	SPC	Attala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 36 more	55 min
Apr 27, 4:21 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Franklin, Jefferson, Lincoln, Pike and 1 more	114 min
Apr 27, 5:32 PM CDT	Tornado Watch	SPC	Calhoun, Chickasaw, Coahoma, DeSoto, Itawamba, Lafayette and 11 more	3 hr

Nearby

Mesoscale Discussions in Mississippi, 2014 Every mesoscale discussion in 2014

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.