Alert archive / Alabama / Mesoscale Discussions in 2003

Mesoscale Discussion 425

April 6, 200317 counties in Alabama

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 11:39 PM CDT for 17 counties in Alabama. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 6, 2003, 11:39 PM CDT (04:39 UTC)
Expired
Apr 7, 2003, 1:45 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Autauga County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Escambia County, AL, Lowndes County, AL, Marengo County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL

The radar

The Birmingham radar (KBMX), 124 km from the middle of the area, began a volume at 04:39 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

Birmingham, AL (KBMX), launched 00:00Z, 4.7 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, Birmingham, AL at 00:00Z on 2003-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 677 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, Birmingham, AL at 00:00Z on 2003-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 133 square meters per square second.1939587897Sfc1 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
677 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
1007 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
133 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.4

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 6, 8:13 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Dallas, Fayette, Greene and 8 more2 hr
Apr 6, 9:48 PM CDTMesoscale DiscussionSPCAutauga, Chilton, Choctaw, Clarke, Dallas, Hale and 6 more87 min
Apr 6, 10:15 PM CDTTornado WatchSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 10 more5 hr
Apr 7, 1:51 AM CDTMesoscale DiscussionSPCBullock, Butler, Lowndes, Macon, Montgomery54 min
Apr 7, 2:55 AM CDTTornado WatchSPCAutauga, Barbour, Bullock, Chilton, Choctaw, Dallas and 13 more4 hr
Apr 7, 4:49 AM CDTMesoscale DiscussionSPCAutauga, Chambers, Chilton, Coosa, Dallas, Elmore and 11 more3 hr
Apr 7, 9:11 AM CDTMesoscale DiscussionSPCBarbour, Coffee, Conecuh, Covington, Crenshaw, Dale and 6 more3 hr
Apr 7, 9:40 AM CDTTornado WatchSPCBarbour, Bullock, Macon, Pike, Russell5 hr
Apr 7, 11:25 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more3 hr
Apr 7, 12:07 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 12:22 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 3:40 PM CDTSevere Thunderstorm WatchSPCBaldwin, Covington, Escambia, Mobile5 hr
Apr 7, 5:58 PM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile2 hr

Nearby

Mesoscale Discussions in Alabama, 2003Every mesoscale discussion in 2003

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.