Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 250
The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2021, 1:40 AM CDT for 46 counties in Texas. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Mar 25, 2021, 1:40 AM CDT (06:40 UTC)
- Expired
- Mar 25, 2021, 3:15 AM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 49
All 46 counties
Anderson County, TX, Bandera County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Bosque County, TX, Burnet County, TX, Camp County, TX, Comal County, TX, Coryell County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gillespie County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Lampasas County, TX, Limestone County, TX, Llano County, TX, McLennan County, TX, Medina County, TX, Milam County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Real County, TX, Robertson County, TX, Rockwall County, TX, Smith County, TX, Titus County, TX, Travis County, TX, Upshur County, TX, Uvalde County, TX, Van Zandt County, TX, Williamson County, TX, Wood County, TX, Zavala County, TX
The radar
The Ft Hood radar (KGRK), 54 km from the middle of the area, began a volume at 06:43 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 nearest sounding before it
Del Rio, TX (KDRT), launched 00:00Z, 6.7 hours before the alert went out and 380 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
- 479 J/kg
- Mixed-layer CIN
- -29 J/kg
- Mixed-layer LCL
- 2767 m above ground
- 0-6 km bulk shear
- 80 kt
- 0-1 km storm-relative helicity
- 13 m²/s²
- 0-3 km storm-relative helicity
- 317 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.9
The text
As transmitted.
120
ACUS11 KWNS 250641
SWOMCD
SPC MCD 250640
TXZ000-250815-
Mesoscale Discussion 0250
NWS Storm Prediction Center Norman OK
0140 AM CDT Thu Mar 25 2021
Areas affected...south-central into northeast TX
Concerning...Tornado Watch 49...
Valid 250640Z - 250815Z
The severe weather threat for Tornado Watch 49 continues.
SUMMARY...Overall severe potential is gradually diminishing across
WW 49. An isolated threat for large hail may persist in the short
term across south-central TX. A downstream watch is not expected.
DISCUSSION...Strong MLCIN is noted in 06z mesoanalysis data, as well
as in the 00z CRP RAOB. Furthermore, convection across north Texas
has become undercut by the cold front and has since weakened. To the
south, toward the Edwards Plateau vicinity, convection is mainly
along the cold front, but regional radar reflectivity shows outflow
has surged ahead of this convection. While a corridor of relatively
weaker MLCIN exists across south-central Texas, the environmental
conditions will quickly become more hostile as storms approach the
edge of WW 49. Steep lapse rates and strong shear exist, so some
large hail potential may persist another 1-2 hours, along with some
gusty winds with outflow, but overall severe threat appears to be
diminishing.
..Leitman.. 03/25/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SHV...HGX...FWD...EWX...SJT...
LAT...LON 30359947 31179867 32879650 33499551 33609507 33459473
33099471 32129533 31259612 30499692 29109869 28789992
28720062 29180082 30359947SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 24, 7:37 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Collin, Cooke, Dallas and 23 more | 53 min |
| Mar 24, 8:15 PM CDT | Mesoscale Discussion | SPC | Bandera, Bell, Blanco, Bosque, Brown, Burnet and 29 more | 2 hr |
| Mar 24, 9:52 PM CDT | Tornado Watch | SPC | Bandera, Bell, Bexar, Blanco, Bosque, Burnet and 37 more | 6 hr |
| Mar 24, 10:28 PM CDT | Mesoscale Discussion | SPC | Edwards, Kimble | 62 min |
| Mar 24, 11:37 PM CDT | Mesoscale Discussion | SPC | Bowie, Cass, Lamar, Morris, Red River, Titus | 53 min |
| Mar 24, 11:42 PM CDT | Mesoscale Discussion | SPC | Burnet, Coryell, Lampasas, Llano, Mason, San Saba | 93 min |
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.