Alert archive / Mississippi / Mesoscale Discussions in 2004

Mesoscale Discussion 504

April 29, 200434 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2004, 8:58 PM CDT for 34 counties in Mississippi. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2004, 8:58 PM CDT (01:58 UTC)
Expired
Apr 29, 2004, 10:00 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 34 counties

Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Itawamba County, MS, Jasper County, MS, Kemper County, MS, Lafayette County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Rankin County, MS, Scott County, MS, Smith County, MS, Union County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Columbus AFB radar (KGWX), 115 km from the middle of the area, began a volume at 02:00 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.

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 2.0 hours before the alert went out and 125 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-pSkew-T log-p diagram, Jackson, MS at 00:00Z on 2004-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 851 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 00:00Z on 2004-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
851 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
851 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
181 m²/s²
Significant tornado parameter
0.6
Supercell composite
2.8

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.

IssuedProductOfficeCountiesLasted
Apr 29, 7:51 PM CDTMesoscale DiscussionSPCGeorge, Hancock, Harrison, Jackson, Stone54 min
Apr 29, 8:55 PM CDTTornado WatchSPCGeorge, Hancock, Harrison, Jackson, Pearl River, Stone5 hr
Apr 29, 9:25 PM CDTTornado WatchSPCAlcorn, Attala, Benton, Calhoun, Chickasaw, Choctaw and 31 more5 hr
Apr 29, 11:09 PM CDTMesoscale DiscussionSPCGeorge, Hancock, Harrison, Jackson, Pearl River, Stone96 min
Apr 29, 11:41 PM CDTMesoscale DiscussionSPCAlcorn, Attala, Benton, Calhoun, Chickasaw, Choctaw and 31 more64 min
Apr 30, 1:21 AM CDTMesoscale DiscussionSPCGeorge, Hancock, Harrison, Jackson, Pearl River, Stone24 min

Nearby

Mesoscale Discussions in Mississippi, 2004Every 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.