Alert archive / Arkansas / Mesoscale Discussions in 2020

Mesoscale Discussion 497

April 28, 202021 counties in Arkansas; Bryan County, Choctaw County, McCurtain County, Oklahoma; 17 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2020, 10:08 PM CDT for 21 counties in Arkansas; Bryan County, Choctaw County, McCurtain County, Oklahoma; 17 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Apr 28, 2020, 10:08 PM CDT (03:08 UTC)
Expired
Apr 28, 2020, 11:45 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
All 41 counties

Clark County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Garland County, AR, Hot Spring County, AR, Howard County, AR, Independence County, AR, Jackson County, AR, Lawrence County, AR, Little River County, AR, Lonoke County, AR, Montgomery County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pulaski County, AR, Saline County, AR, Sevier County, AR, White County, AR, Bryan County, OK, Choctaw County, OK, McCurtain County, OK, Collin County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Fannin County, TX, Grayson County, TX, Hopkins County, TX, Hunt County, TX, Jack County, TX, Lamar County, TX, Palo Pinto County, TX, Parker County, TX, Red River County, TX, Rockwall County, TX, Tarrant County, TX, Wise County, TX

The radar

The Western Arkansas radar (KSRX), 98 km from the middle of the area, began a volume at 03:11 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

Shreveport, LA (KSHV), launched 00:00Z, 3.1 hours before the alert went out and 221 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 00:00Z on 2020-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 733 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 00:00Z on 2020-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 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
733 J/kg
Mixed-layer CIN
-250 J/kg
Mixed-layer LCL
1058 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 28, 7:35 PM CDTSevere Thunderstorm WatchSPCArkansas, Baxter, Boone, Bradley, Calhoun, Clark and 51 more7 hr
Apr 28, 8:06 PM CDTMesoscale DiscussionSPCLafayette, Little River, Miller, Sevier54 min
Apr 28, 8:25 PM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more9 hr
Apr 28, 11:12 PM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Cleveland, Crittenden, Cross and 11 more63 min
Apr 28, 11:57 PM CDTMesoscale DiscussionSPCAshley, Chicot63 min
Apr 29, 12:48 AM CDTSevere Thunderstorm WatchSPCAshley, Chicot4 hr
Apr 28, 7:02 PM CDTMesoscale DiscussionSPCCarter, Cleveland, Cotton, Garvin, Grady, Jefferson and 7 more88 min
Apr 28, 9:04 PM CDTMesoscale DiscussionSPCJim Hogg, Starr, Zapata116 min
Apr 29, 1:56 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Bell, Bosque, Brazos, Burleson and 28 more2 hr
Apr 29, 2:40 AM CDTSevere Thunderstorm WatchSPCAustin, Bastrop, Brazoria, Burnet, Caldwell, Chambers and 25 more6 hr
Apr 29, 5:05 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Blanco, Brazoria, Caldwell, Calhoun and 25 more115 min

Nearby

Mesoscale Discussions in Arkansas, 2020Mesoscale Discussions in Texas, 2020Mesoscale Discussions in Oklahoma, 2020Every mesoscale discussion in 2020

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.