Alert archive / Alabama / Mesoscale Discussions in 2008

Mesoscale Discussion 665

April 18, 200814 counties in Alabama; 5 counties in Florida; George County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2008, 10:21 PM CDT for 14 counties in Alabama; 5 counties in Florida; George County, Jackson County, Mississippi. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Apr 18, 2008, 10:21 PM CDT (03:21 UTC)
Expired: Apr 18, 2008, 11:15 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center

All 21 counties

Baldwin County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Geneva County, AL, Mobile County, AL, Monroe County, AL, Pike County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, George County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 100 km from the middle of the area, began a volume at 03:24 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

Slidell Radar S, LA (KSIL), launched 00:00Z, 3.4 hours before the alert went out and 247 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: 695 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 712 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 396 m²/s²
0-3 km storm-relative helicity: 515 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 9.2

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 18, 8:33 PM CDT	Mesoscale Discussion	SPC	Baldwin, Choctaw, Clarke, Conecuh, Escambia, Mobile and 4 more	57 min
Apr 18, 11:37 PM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Conecuh, Covington, Crenshaw, Escambia and 2 more	53 min
Apr 18, 9:44 PM CDT	Mesoscale Discussion	SPC	George, Greene, Harrison, Jackson	31 min

Nearby

Mesoscale Discussions in Alabama, 2008 Mesoscale Discussions in Florida, 2008 Mesoscale Discussions in Mississippi, 2008 Every mesoscale discussion in 2008

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.