Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 316

April 16, 20156 parishes in Louisiana; 18 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2015, 4:59 PM CDT for 6 parishes in Louisiana; 18 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 16, 2015, 4:59 PM CDT (21:59 UTC)
Expired
Apr 16, 2015, 6:30 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 24 counties

Beauregard Parish, LA, De Soto Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Angelina County, TX, Cherokee County, TX, Gregg County, TX, Hardin County, TX, Houston County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Smith County, TX, Trinity County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 141 km from the middle of the area, began a volume at 22:00 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

Shreveport, LA (KBAD), launched 12:00Z, 10.0 hours before the alert went out and 153 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, Shreveport, LA at 12:00Z on 2015-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Shreveport, LA at 12:00Z on 2015-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
2 J/kg
Mixed-layer CIN
-456 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 16, 12:49 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Castro, Crosby, Donley and 15 more116 min
Apr 16, 1:34 PM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Bexar, Blanco, Bosque and 48 more116 min
Apr 16, 1:48 PM CDTTornado WatchSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hansford and 8 more8 hr
Apr 16, 2:22 PM CDTSevere Thunderstorm WatchSPCAnderson, Aransas, Austin, Bastrop, Bee, Bell and 81 more8 hr
Apr 16, 2:42 PM CDTMesoscale DiscussionSPCAnderson, Aransas, Austin, Bastrop, Bee, Bell and 75 more63 min
Apr 16, 4:06 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Brown, Callahan, Childress and 46 more2 hr
Apr 16, 4:40 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Briscoe, Brown, Callahan, Castro and 45 more7 hr
Apr 16, 5:06 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hansford and 7 more84 min
Apr 16, 5:29 PM CDTMesoscale DiscussionSPCBailey, Dallam, Deaf Smith, Hartley, Oldham, Parmer91 min
Apr 16, 6:19 PM CDTMesoscale DiscussionSPCAnderson, Aransas, Austin, Bastrop, Bell, Bexar and 84 more86 min

Nearby

Mesoscale Discussions in Texas, 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; radar from the NEXRAD Level II archive.