Alert archive / Louisiana / Mesoscale Discussions in 2007

Mesoscale Discussion 592

April 26, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2007, 4:46 AM CDT for 4 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Apr 26, 2007, 4:46 AM CDT (09:46 UTC)
Expired: Apr 26, 2007, 6:15 AM CDT
In force: 89 min
Issued by: the Storm Prediction Center

All 37 counties

Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Ascension Parish, LA, Assumption Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, Clarke County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 80 km from the middle of the area, began a volume at 09:46 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, 9.8 hours before the alert went out and 76 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: 583 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 1060 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

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 25, 11:50 PM CDT	Mesoscale Discussion	SPC	Mobile, Washington	85 min
Apr 26, 12:41 AM CDT	Tornado Watch	SPC	Baldwin, Choctaw, Clarke, Mobile, Washington	7 hr
Apr 26, 7:12 AM CDT	Mesoscale Discussion	SPC	Baldwin, Clarke, Mobile, Monroe, Washington	93 min
Apr 26, 2:12 PM CDT	Mesoscale Discussion	SPC	Barbour, Bullock, Chambers, Coffee, Covington, Crenshaw and 12 more	63 min
Apr 26, 2:42 PM CDT	Tornado Watch	SPC	Barbour, Bullock, Coffee, Dale, Geneva, Henry and 3 more	3 hr
Apr 26, 4:33 PM CDT	Mesoscale Discussion	SPC	Cherokee, DeKalb, Etowah, Jackson, Marshall	57 min
Apr 26, 4:53 PM CDT	Tornado Watch	SPC	DeKalb, Jackson, Marshall	5 hr
Apr 26, 5:26 PM CDT	Mesoscale Discussion	SPC	Henry, Houston	64 min

Nearby

Mesoscale Discussions in Louisiana, 2007 Mesoscale Discussions in Mississippi, 2007 Mesoscale Discussions in Alabama, 2007 Every mesoscale discussion in 2007

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.