Alert archive / Alabama / Mesoscale Discussions in 2008

Mesoscale Discussion 255

February 17, 20084 states

The Storm Prediction Center issued this mesoscale discussion at Feb 17, 2008, 7:13 AM CST for 4 states. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Feb 17, 2008, 7:13 AM CST (13:13 UTC)
Expired: Feb 17, 2008, 8:15 AM CST
In force: 62 min
Issued by: the Storm Prediction Center

All 46 counties

Autauga County, AL, Baldwin County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Escambia County, AL, Greene County, AL, Hale County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Jefferson Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Tammany Parish, LA, Clarke County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jasper County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 44 km from the middle of the area, began a volume at 13:12 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 12:00Z, 1.2 hours before the alert went out and 158 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: 412 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 645 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 233 m²/s²
0-3 km storm-relative helicity: 242 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 2.6

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
Feb 17, 2:13 AM CST	Mesoscale Discussion	SPC	Mobile	32 min
Feb 17, 4:19 AM CST	Mesoscale Discussion	SPC	Colbert, Franklin, Lamar, Marion, Pickens	56 min
Feb 17, 5:05 AM CST	Mesoscale Discussion	SPC	Baldwin, Choctaw, Clarke, Conecuh, Dallas, Escambia and 8 more	55 min
Feb 17, 5:26 AM CST	Tornado Watch	SPC	Autauga, Baldwin, Butler, Choctaw, Clarke, Conecuh and 14 more	7 hr
Feb 17, 9:43 AM CST	Mesoscale Discussion	SPC	Autauga, Baldwin, Butler, Chilton, Choctaw, Clarke and 17 more	62 min
Feb 17, 12:14 PM CST	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Chambers, Clay, Coffee and 16 more	91 min
Feb 17, 12:32 PM CST	Tornado Watch	SPC	Autauga, Baldwin, Barbour, Bullock, Butler, Chambers and 28 more	7 hr
Feb 17, 2:45 PM CST	Mesoscale Discussion	SPC	Autauga, Baldwin, Barbour, Bullock, Butler, Chambers and 22 more	90 min
Feb 17, 5:19 PM CST	Mesoscale Discussion	SPC	Chambers, Dale, Geneva, Henry, Houston	86 min
Feb 17, 5:58 PM CST	Tornado Watch	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 6 more	8 hr
Feb 16, 7:18 PM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Calcasieu, Cameron, De Soto, Jefferson Davis and 4 more	87 min
Feb 16, 8:25 PM CST	Tornado Watch	SPC	Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 4 more	6 hr
Feb 16, 10:41 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 26 more	94 min
Feb 16, 11:30 PM CST	Severe Thunderstorm Watch	SPC	Ascension, Assumption, Avoyelles, Caldwell, Catahoula, Concordia and 25 more	6 hr
Feb 17, 1:33 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Cameron, Evangeline, Jefferson Davis, Rapides and 1 more	57 min
Feb 17, 2:45 AM CST	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 19 more	5 hr

Nearby

Mesoscale Discussions in Alabama, 2008 Mesoscale Discussions in Mississippi, 2008 Mesoscale Discussions in Louisiana, 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.