Alert archive / Texas / Mesoscale Discussions in 2017
Mesoscale Discussion 543
The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2017, 11:39 PM CDT for 4 states. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2017, 11:39 PM CDT (04:39 UTC)
- Expired
- Apr 22, 2017, 1:15 AM CDT
- In force
- 96 min
- Issued by
- the Storm Prediction Center
All 61 counties
Calhoun County, AR, Clark County, AR, Columbia County, AR, Dallas County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sevier County, AR, Union County, AR, Bossier Parish, LA, Webster Parish, LA, Choctaw County, OK, McCurtain County, OK, Bosque County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Navarro County, TX, Parker County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wise County, TX, Wood County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 176 km from the middle of the area, began a volume at 04:43 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
Fort Worth, TX (KFWD), launched 00:00Z, 4.7 hours before the alert went out and 167 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.
- Mixed-layer CAPE
- 1220 J/kg
- Mixed-layer CIN
- -102 J/kg
- Mixed-layer LCL
- 1576 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 203 m²/s²
- 0-3 km storm-relative helicity
- 219 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 12.5
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 7:11 PM CDT | Mesoscale Discussion | SPC | Howard, Little River, Montgomery, Pike, Polk, Scott and 3 more | 94 min |
| Apr 21, 9:28 PM CDT | Mesoscale Discussion | SPC | Garland, Hempstead, Howard, Little River, Miller, Montgomery and 5 more | 92 min |
| Apr 22, 12:41 AM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more | 6 hr |
| Apr 22, 4:16 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 3 more | 89 min |
| Apr 22, 12:51 PM CDT | Mesoscale Discussion | SPC | Chicot | 114 min |
| Apr 22, 4:56 PM CDT | Mesoscale Discussion | SPC | Madison, Tensas | 64 min |
Nearby
Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Louisiana, 2017Every mesoscale discussion in 2017
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.