Alert archive / Alabama / Mesoscale Discussions in 2018

Mesoscale Discussion 254

April 14, 201824 counties in Alabama; Escambia County, Florida; George County, Greene County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2018, 9:40 AM CDT for 24 counties in Alabama; Escambia County, Florida; George County, Greene County, Jackson County, Mississippi. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 14, 2018, 9:40 AM CDT (14:40 UTC)
Expired
Apr 14, 2018, 11:15 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 28 counties

Autauga County, AL, Baldwin County, AL, Bibb County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Coosa County, AL, Dallas County, AL, Escambia County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Perry County, AL, Shelby County, AL, Talladega County, AL, Tuscaloosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, George County, MS, Greene County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 139 km from the middle of the area, began a volume at 14:43 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 12:00Z, 2.7 hours before the alert went out and 171 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 12:00Z on 2018-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 224 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 12:00Z on 2018-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 275 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
224 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
560 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
275 m²/s²
0-3 km storm-relative helicity
324 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.7

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
Apr 14, 4:35 AM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lauderdale, Marion and 1 more115 min
Apr 14, 6:37 AM CDTMesoscale DiscussionSPCSumter83 min
Apr 14, 10:36 AM CDTTornado WatchSPCAutauga, Baldwin, Bibb, Blount, Butler, Chilton and 22 more8 hr
Apr 14, 12:41 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Butler, Chilton, Choctaw and 18 more94 min
Apr 14, 2:56 PM CDTMesoscale DiscussionSPCAutauga, Chilton, Coosa, Dallas, Lowndes, Mobile and 5 more94 min
Apr 14, 6:17 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Conecuh, Covington, Escambia and 2 more118 min
Apr 14, 6:55 PM CDTTornado WatchSPCBaldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 7 more6 hr
Apr 13, 7:22 PM CDTTornado WatchSPCAdams, Bolivar, Claiborne, Franklin, Issaquena, Jefferson and 4 more3 hr
Apr 13, 10:12 PM CDTTornado WatchSPCAdams, Alcorn, Benton, Bolivar, Calhoun, Carroll and 33 more10 hr
Apr 14, 2:10 AM CDTMesoscale DiscussionSPCAdams, Attala, Benton, Bolivar, Calhoun, Carroll and 32 more2 hr
Apr 14, 6:57 AM CDTTornado WatchSPCAmite, Attala, Choctaw, Clarke, Clay, Copiah and 30 more7 hr

Nearby

Mesoscale Discussions in Alabama, 2018Mesoscale Discussions in Mississippi, 2018Mesoscale Discussions in Florida, 2018Every mesoscale discussion in 2018

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.