Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 401

April 5, 200920 counties in Alabama

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2009, 4:02 PM CDT for 20 counties in Alabama. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Apr 5, 2009, 4:02 PM CDT (21:02 UTC)
Expired: Apr 5, 2009, 5:00 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Autauga County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Lowndes County, AL, Monroe County, AL, Montgomery County, AL, Pike County, AL, Wilcox County, AL

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 118Apr 5, 5:05 PM CDT

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 9.0 hours before the alert went out and 262 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: 1202 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 126 m²/s²
0-3 km storm-relative helicity: 137 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
Apr 5, 5:57 AM CDT	Mesoscale Discussion	SPC	Baldwin, Barbour, Bullock, Butler, Choctaw, Clarke and 18 more	93 min
Apr 5, 9:29 AM CDT	Mesoscale Discussion	SPC	Chambers, Clay, Cleburne, Coosa, Lee, Macon and 4 more	91 min
Apr 5, 5:05 PM CDT	Tornado Watch	SPC	Autauga, Barbour, Bullock, Butler, Chambers, Chilton and 21 more	6 hr
Apr 5, 6:19 PM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Jackson, Lauderdale, Lawrence, Limestone and 1 more	86 min

Nearby

Mesoscale Discussions in Alabama, 2009 Every mesoscale discussion in 2009

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.