Alert archive / Texas / Mesoscale Discussions in 2020
Mesoscale Discussion 21
The Storm Prediction Center issued this mesoscale discussion at Jan 10, 2020, 7:30 PM CST for 5 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 10, 2020, 7:30 PM CST (01:30 UTC)
- Expired
- Jan 10, 2020, 9:30 PM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 101 counties
Baxter County, AR, Boone County, AR, Clark County, AR, Cleburne County, AR, Columbia County, AR, Conway County, AR, Crawford County, AR, Dallas County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Izard County, AR, Johnson County, AR, Lafayette County, AR, Little River County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Newton County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Stone County, AR, Van Buren County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, Webster Parish, LA, Crawford County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Ozark County, MO, Phelps County, MO, Pulaski County, MO, Shannon County, MO, Texas County, MO, Wright County, MO, Choctaw County, OK, McCurtain County, OK, Anderson County, TX, Angelina County, TX, Bell County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Marion County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Trinity County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX
The radar
The Western Arkansas radar (KSRX), 124 km from the middle of the area, began a volume at 01:30 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 00:00Z, 1.5 hours before the alert went out and 196 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
- 703 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 813 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 379 m²/s²
- 0-3 km storm-relative helicity
- 620 m²/s²
- Significant tornado parameter
- 1.6
- Supercell composite
- 6.1
The text
As transmitted.
421
ACUS11 KWNS 110130
SWOMCD
SPC MCD 110130
MOZ000-ARZ000-LAZ000-TXZ000-OKZ000-110330-
Mesoscale Discussion 0021
NWS Storm Prediction Center Norman OK
0730 PM CST Fri Jan 10 2020
Areas affected...northeast Texas/southeast Oklahoma into the
Arklatex and Ozarks...and much of Arkansas
Concerning...Tornado Watch 3...5...
Valid 110130Z - 110330Z
The severe weather threat for Tornado Watch 3, 5 continues.
SUMMARY...Severe weather risk continues, including potential for a
few tornadoes across WW 003 and 005.
DISCUSSION...Radar continues to show a nearly contiguous line of
convection near the advancing surface front, from central and
eastern Missouri south-southwestward to the lower Rio Grande Valley.
Within this band, occasional rotating updrafts continue to
periodically evolve and then diminish -- temporarily enhancing
severe risk as the spin-ups reach peak intensity. Meanwhile, broken
bands of pre-frontal storms continue -- from central Texas
north-northeast to west-central Arkansas. While this convection
continues struggling to organize overall, occasional rotating storms
evolve -- aided by favorably strong/veering flow with height
supportive of supercells.
Within both of these regimes (the near-frontal band of storms as
well as the warm-sector pre-frontal convection), severe risk
continues, including potential for a few tornadoes.
..Goss.. 01/11/2020
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...LZK...SGF...SHV...TSA...HGX...FWD...OUN...
LAT...LON 30779699 31099767 33009693 33929615 34249514 35079450
35849424 36859271 38019221 38029128 37209135 35969172
33109297 31839400 31079477 30779699SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 10, 10:40 PM CST | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 40 more | 2 hr |
| Jan 10, 11:58 PM CST | Tornado Watch | SPC | Ashley, Chicot, Clay, Craighead, Crittenden, Cross and 6 more | 7 hr |
| Jan 11, 12:28 AM CST | Tornado Watch | SPC | Union | 8 hr |
| Jan 11, 3:52 AM CST | Mesoscale Discussion | SPC | Crittenden, Desha, Lee, Mississippi, Phillips, St. Francis | 83 min |
| Jan 11, 12:21 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 11 more | 99 min |
| Jan 11, 1:19 AM CST | Mesoscale Discussion | SPC | Bienville, Caldwell, Claiborne, De Soto, Jackson, Lincoln and 7 more | 86 min |
| Jan 11, 2:22 AM CST | Mesoscale Discussion | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more | 53 min |
| Jan 11, 2:37 AM CST | Tornado Watch | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more | 8 hr |
| Jan 11, 4:31 AM CST | Mesoscale Discussion | SPC | Acadia, Ascension, Avoyelles, Caldwell, Catahoula, Concordia and 21 more | 59 min |
| Jan 11, 5:18 AM CST | Tornado Watch | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more | 7 hr |
| Jan 11, 7:39 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 8 more | 96 min |
| Jan 11, 3:10 PM CST | Mesoscale Discussion | SPC | Audrain, Boone, Callaway, Cole, Crawford, Franklin and 15 more | 4 hr |
| Jan 11, 8:21 AM CST | Mesoscale Discussion | SPC | Creek, Nowata, Osage, Rogers, Tulsa, Washington | 114 min |
| Jan 10, 6:30 PM CST | Mesoscale Discussion | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 16 more | 2 hr |
| Jan 10, 8:49 PM CST | Mesoscale Discussion | SPC | Angelina, Austin, Brazoria, Brazos, Burleson, Chambers and 25 more | 116 min |
| Jan 10, 9:09 PM CST | Tornado Watch | SPC | Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more | 5 hr |
| Jan 11, 7:34 AM CST | Mesoscale Discussion | SPC | Cooke, Denton, Fannin, Grayson | 116 min |
Nearby
Mesoscale Discussions in Texas, 2020Mesoscale Discussions in Arkansas, 2020Mesoscale Discussions in Missouri, 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.