Alert archive / Alabama / Mesoscale Discussions in 2015

Mesoscale Discussion 455

April 25, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2015, 1:50 PM CDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 25, 2015, 1:50 PM CDT (18:50 UTC)
Expired
Apr 25, 2015, 3:15 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 29 counties

Baldwin County, AL, Butler County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Washington Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.8 hours before the alert went out and 101 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 2015-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1826 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 2015-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 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
1826 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
565 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
1.0
Supercell composite
4.6

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 25, 12:50 AM CDTTornado WatchSPCDallas, Fayette, Greene, Hale, Lamar, Marengo and 4 more6 hr
Apr 25, 2:07 AM CDTMesoscale DiscussionSPCChoctaw, Greene, Pickens, Sumter, Tuscaloosa83 min
Apr 25, 4:12 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Choctaw, Clarke, Conecuh, Dallas and 9 more63 min
Apr 25, 5:00 AM CDTTornado WatchSPCAutauga, Baldwin, Barbour, Bullock, Butler, Clarke and 18 more7 hr
Apr 25, 7:41 AM CDTMesoscale DiscussionSPCCoffee, Covington, Dale, Geneva, Henry, Houston94 min
Apr 25, 9:35 AM CDTMesoscale DiscussionSPCBaldwin, Mobile, Washington115 min
Apr 25, 1:36 PM CDTSevere Thunderstorm WatchSPCBaldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 5 more4 hr
Apr 25, 2:10 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Bullock, Calhoun, Chambers, Chilton and 19 more95 min
Apr 25, 3:07 PM CDTSevere Thunderstorm WatchSPCBarbour, Coffee, Dale, Geneva, Henry, Houston and 1 more7 hr
Apr 25, 4:38 PM CDTSevere Thunderstorm WatchSPCBullock, Chambers, Clay, Lee, Macon, Randolph and 2 more5 hr
Apr 25, 8:08 AM CDTTornado WatchSPCBaker, Calhoun, Columbia, Duval, Franklin, Gadsden and 11 more7 hr
Apr 25, 11:20 AM CDTMesoscale DiscussionSPCColumbia, Gadsden, Hamilton, Jefferson, Lafayette, Leon and 5 more85 min
Apr 25, 2:30 PM CDTMesoscale DiscussionSPCBaker, Columbia, Duval, Gadsden, Hamilton, Jefferson and 5 more60 min
Apr 25, 6:19 PM CDTMesoscale DiscussionSPCCalhoun, Franklin, Gadsden, Gulf, Hamilton, Jackson and 6 more56 min
Apr 24, 7:46 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 7 more89 min
Apr 24, 9:20 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more55 min
Apr 24, 9:59 PM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 14 more4 hr
Apr 24, 11:45 PM CDTMesoscale DiscussionSPCCaldwell, East Carroll, Franklin, Jackson, Madison, Morehouse and 5 more90 min
Apr 25, 7:12 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more6 hr
Apr 25, 10:41 AM CDTSevere Thunderstorm WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more7 hr

Nearby

Mesoscale Discussions in Alabama, 2015Mesoscale Discussions in Mississippi, 2015Mesoscale Discussions in Louisiana, 2015Every mesoscale discussion in 2015

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.