Alert archive / Alabama / Mesoscale Discussions in 2017

Mesoscale Discussion 330

March 25, 20178 counties in Alabama; 7 parishes in Louisiana; 4 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2017, 12:08 PM CDT for 8 counties in Alabama; 7 parishes in Louisiana; 4 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 25, 2017, 12:08 PM CDT (17:08 UTC)
Expired
Mar 25, 2017, 2:45 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Bibb County, AL, Chilton County, AL, Clarke County, AL, Dallas County, AL, Mobile County, AL, Monroe County, AL, Perry County, AL, Wilcox County, AL, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 81 km from the middle of the area, began a volume at 17:08 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 12:00Z, 5.1 hours before the alert went out and 88 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, Slidell Radar S, LA at 12:00Z on 2017-03-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 925 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, Slidell Radar S, LA at 12:00Z on 2017-03-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 222 square meters per square second.19395878Sfc1 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
925 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
530 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
222 m²/s²
0-3 km storm-relative helicity
232 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.3

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 8:39 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more66 min
Mar 24, 9:14 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Claiborne, Jackson, Lincoln and 3 more6 hr
Mar 24, 9:23 PM CDTTornado WatchSPCCaldwell, De Soto, Grant, LaSalle, Natchitoches, Red River and 2 more6 hr
Mar 24, 9:58 PM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 2 more62 min
Mar 24, 10:28 PM CDTTornado WatchSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 1 more6 hr
Mar 24, 11:41 PM CDTMesoscale DiscussionSPCAvoyelles, Caldwell, Catahoula, Concordia, East Carroll, Franklin and 7 more64 min
Mar 25, 12:05 AM CDTSevere Thunderstorm WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more5 hr
Mar 25, 2:08 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 6 more67 min
Mar 25, 3:06 AM CDTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Richland and 1 more54 min
Mar 25, 5:25 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Vernon2 hr
Mar 25, 1:05 AM CDTMesoscale DiscussionSPCBenton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 4 more115 min
Mar 25, 1:34 PM CDTMesoscale DiscussionSPCAttala, Calhoun, Carroll, Chickasaw, Choctaw, Grenada and 9 more116 min

Nearby

Mesoscale Discussions in Alabama, 2017Mesoscale Discussions in Louisiana, 2017Mesoscale Discussions in Mississippi, 2017Every mesoscale discussion in 2017

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.