Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 346

March 31, 20095 counties in Alabama; 5 counties in Florida; George County, Greene County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2009, 11:32 AM CDT for 5 counties in Alabama; 5 counties in Florida; George County, Greene County, Jackson County, Mississippi. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Mar 31, 2009, 11:32 AM CDT (16:32 UTC)
Expired: Mar 31, 2009, 1:00 PM CDT
In force: 88 min
Issued by: the Storm Prediction Center

Counties Baldwin County, AL, Covington County, AL, Escambia County, AL, Mobile County, AL, Washington County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, George County, MS, Greene County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 60 km from the middle of the area, began a volume at 16:33 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.

Severe Thunderstorm Watch 98Mar 31, 1:00 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 4.5 hours before the alert went out and 206 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: 377 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 522 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 287 m²/s²
0-3 km storm-relative helicity: 408 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.2

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
Mar 31, 11:54 AM CDT	Mesoscale Discussion	SPC	Sumter	96 min
Mar 31, 1:05 PM CDT	Severe Thunderstorm Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 11 more	8 hr
Mar 31, 3:15 PM CDT	Mesoscale Discussion	SPC	Coffee, Covington, Dale, Escambia, Geneva, Henry and 1 more	90 min
Mar 31, 5:12 PM CDT	Mesoscale Discussion	SPC	Baldwin, Clarke, Coffee, Conecuh, Covington, Dale and 7 more	93 min
Mar 31, 4:17 PM CDT	Mesoscale Discussion	SPC	Baker, Bradford, Clay, Columbia, Duval, Nassau and 2 more	28 min
Mar 31, 4:25 PM CDT	Severe Thunderstorm Watch	SPC	Baker, Columbia, Duval, Gilchrist, Hamilton, Nassau and 2 more	7 hr
Mar 31, 6:59 PM CDT	Mesoscale Discussion	SPC	Baker, Columbia, Hamilton, Jefferson, Lafayette, Leon and 5 more	91 min
Mar 31, 8:58 AM CDT	Mesoscale Discussion	SPC	Adams, Amite, Copiah, Covington, Forrest, Franklin and 13 more	92 min
Mar 31, 9:37 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Amite, Claiborne, Clarke, Copiah, Covington and 29 more	7 hr
Mar 31, 2:44 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Claiborne, Clarke, Copiah and 35 more	91 min

Nearby

Mesoscale Discussions in Alabama, 2009 Mesoscale Discussions in Florida, 2009 Mesoscale Discussions in Mississippi, 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; radar from the NEXRAD Level II archive.