Alert archive / Arkansas / Mesoscale Discussions in 2020

Mesoscale Discussion 446

April 22, 202012 counties in Arkansas; McCurtain County, Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2020, 6:39 PM CDT for 12 counties in Arkansas; McCurtain County, Oklahoma; 8 counties in Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Apr 22, 2020, 6:39 PM CDT (23:39 UTC)
Expired
Apr 22, 2020, 7:45 PM CDT
In force
66 min
Issued by
the Storm Prediction Center
All 21 counties

Clark County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Pike County, AR, Polk County, AR, Sevier County, AR, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Marion County, TX, Morris County, TX, Red River County, TX, Titus County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 157 km from the middle of the area, began a volume at 23:38 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 (KSHV), launched 12:00Z, 11.7 hours before the alert went out and 156 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 2020-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 24 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 2020-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.1939587897117Sfc1 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
24 J/kg
Mixed-layer CIN
-457 J/kg
Mixed-layer LCL
1104 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
379 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

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 22, 1:46 AM CDTSevere Thunderstorm WatchSPCHoward, Little River, Sevier4 hr
Apr 22, 8:53 AM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more6 hr
Apr 22, 11:29 AM CDTMesoscale DiscussionSPCSebastian91 min
Apr 21, 9:10 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Carter, Cleveland and 24 more95 min
Apr 21, 11:32 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Carter, Cleveland and 24 more88 min
Apr 22, 1:21 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 7 more84 min
Apr 22, 2:16 AM CDTMesoscale DiscussionSPCBeaver, Ellis, Harper, Texas, Woods, Woodward119 min
Apr 22, 8:36 AM CDTMesoscale DiscussionSPCAtoka, Blaine, Caddo, Canadian, Carter, Cleveland and 26 more84 min
Apr 22, 1:12 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 7 more63 min
Apr 22, 2:33 PM CDTTornado WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 11 more6 hr
Apr 22, 4:43 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Coal, Garvin, Johnston, Marshall and 2 more62 min
Apr 21, 8:12 PM CDTMesoscale DiscussionSPCHemphill, Lipscomb, Wheeler63 min
Apr 22, 10:38 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Blanco and 50 more2 hr
Apr 22, 10:55 AM CDTTornado WatchSPCAnderson, Angelina, Austin, Bastrop, Brazos, Burleson and 31 more6 hr
Apr 22, 1:10 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Brazos and 35 more65 min
Apr 22, 2:53 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Cherokee, Houston, Nacogdoches, Panola and 5 more67 min
Apr 22, 4:24 PM CDTMesoscale DiscussionSPCAngelina, Brazos, Cherokee, Grimes, Hardin, Houston and 14 more96 min
Apr 22, 4:47 PM CDTMesoscale DiscussionSPCAngelina, Polk, San Augustine, San Jacinto, Trinity, Tyler and 1 more88 min
Apr 22, 5:01 PM CDTTornado WatchSPCAngelina, Cherokee, Grimes, Harrison, Houston, Jasper and 14 more9 hr
Apr 22, 5:38 PM CDTMesoscale DiscussionSPCCamp, Collin, Dallas, Delta, Fannin, Franklin and 10 more97 min
Apr 22, 5:53 PM CDTMesoscale DiscussionSPCAngelina, Polk, Trinity, Tyler37 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.