Alert archive / Florida / Mesoscale Discussions in 2004

Mesoscale Discussion 507

April 29, 20045 states

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2004, 11:09 PM CDT for 5 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Apr 29, 2004, 11:09 PM CDT (04:09 UTC)
Expired: Apr 30, 2004, 12:45 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center

All 33 counties

Baldwin County, AL, Coffee County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Mobile County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gadsden County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Seminole County, GA, Jefferson Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Tammany Parish, LA, Washington Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Stone County, MS

The radar

The Mobile radar (KMOB), 107 km from the middle of the area, began a volume at 04:13 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, 4.2 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: 1025 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 490 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 73 m²/s²
0-3 km storm-relative helicity: 128 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.1

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 29, 7:51 PM CDT	Mesoscale Discussion	SPC	Baldwin, Mobile, Monroe	54 min
Apr 29, 8:55 PM CDT	Tornado Watch	SPC	Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more	5 hr
Apr 29, 9:25 PM CDT	Tornado Watch	SPC	Colbert, Franklin, Lauderdale	5 hr
Apr 29, 11:41 PM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Lauderdale	64 min
Apr 30, 1:21 AM CDT	Mesoscale Discussion	SPC	Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more	24 min
Apr 30, 12:20 PM CDT	Mesoscale Discussion	SPC	Alachua, Bradford, Clay, Duval, Flagler, Marion and 3 more	2 hr
Apr 29, 8:58 PM CDT	Mesoscale Discussion	SPC	Attala, Calhoun, Carroll, Chickasaw, Choctaw, Clarke and 28 more	62 min

Nearby

Mesoscale Discussions in Florida, 2004 Mesoscale Discussions in Alabama, 2004 Mesoscale Discussions in Louisiana, 2004 Every mesoscale discussion in 2004

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.