Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 634
The Storm Prediction Center issued this mesoscale discussion at May 16, 2021, 12:15 PM CDT for 28 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 16, 2021, 12:15 PM CDT (17:15 UTC)
- Expired
- May 16, 2021, 2:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 28 counties
Anderson County, TX, Bastrop County, TX, Bell County, TX, Brazos County, TX, Burleson County, TX, Cherokee County, TX, Falls County, TX, Freestone County, TX, Grimes County, TX, Henderson County, TX, Houston County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Montgomery County, TX, Navarro County, TX, Polk County, TX, Robertson County, TX, San Jacinto County, TX, Smith County, TX, Trinity County, TX, Van Zandt County, TX, Walker County, TX, Washington County, TX, Williamson County, TX
The radar
The Ft Hood radar (KGRK), 130 km from the middle of the area, began a volume at 17:16 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 12:00Z, 5.3 hours before the alert went out and 267 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
- 80 J/kg
- Mixed-layer CIN
- -171 J/kg
- Mixed-layer LCL
- 899 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -28 m²/s²
- 0-3 km storm-relative helicity
- -6 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
100
ACUS11 KWNS 161715
SWOMCD
SPC MCD 161715
TXZ000-161915-
Mesoscale Discussion 0634
NWS Storm Prediction Center Norman OK
1215 PM CDT Sun May 16 2021
Areas affected...Central/East TX
Concerning...Severe potential...Watch unlikely
Valid 161715Z - 161915Z
Probability of Watch Issuance...20 percent
SUMMARY...A few strong to severe storms possible this afternoon
across portions of central and east TX. Isolated damaging wind gusts
are the primary threat.
DISCUSSION...Regional satellite and radar imagery reveals a pair of
MCVs across the southern Plains, one over central OK and the other
along the middle TX Coast. Modest southerly low-level flow exists
between these two features, roughly along and east of I-35. The
thermodynamic environment is expected to remain only marginally
buoyant, with overall buoyancy tempered by the limited diurnal
heating. Even so, thunderstorms are expected to persist while
gradually drifting eastward throughout the day.
Surface winds have been backing a bit more southeasterly just ahead
of the storms, which, when coupled with the modest low-level
southerly flow and westerly flow aloft, result in a kinematic
profile that could support a supercell or two. Damaging wind gusts
would be the primary threat with any stronger updrafts/supercells,
with some low-probability potential for a brief tornado as well.
Marginal and isolated nature of the severe threat is expected to
preclude the need for a watch.
..Mosier/Guyer.. 05/16/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SHV...HGX...FWD...EWX...
LAT...LON 31549740 32299689 32619581 32419494 31799459 30429490
29919706 30389770 31549740SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 9:09 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Crosby, Floyd and 11 more | 96 min |
| May 15, 9:32 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Crane, Crockett, Dawson, Ector and 11 more | 88 min |
| May 16, 3:16 PM CDT | Mesoscale Discussion | SPC | Armstrong, Bailey, Briscoe, Carson, Castro, Cochran and 12 more | 119 min |
| May 16, 3:43 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 19 more | 7 hr |
| May 16, 3:46 PM CDT | Mesoscale Discussion | SPC | Archer, Clay, Cooke, Jack, Montague, Wichita and 1 more | 89 min |
| May 16, 5:52 PM CDT | Mesoscale Discussion | SPC | Glasscock, Howard, Irion, Midland, Reagan, Sterling | 53 min |
| May 16, 6:12 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Deaf Smith and 7 more | 93 min |
| May 16, 6:35 PM CDT | Severe Thunderstorm Watch | SPC | Borden, Coke, Crockett, Dawson, Fisher, Glasscock and 12 more | 4 hr |
Nearby
Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021
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.