Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 712
The Storm Prediction Center issued this mesoscale discussion at May 23, 2021, 2:59 PM CDT for 7 counties in Texas. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- May 23, 2021, 2:59 PM CDT (19:59 UTC)
- Expired
- May 23, 2021, 4:30 PM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Crane County, TX, Ector County, TX, Loving County, TX, Pecos County, TX, Reeves County, TX, Ward County, TX, Winkler County, TX
The radar
The Midland/Odessa radar (KMAF), 161 km from the middle of the area, began a volume at 20:00 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
Midland Regional, TX (KMAF), launched 12:00Z, 8.0 hours before the alert went out and 161 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
- 947 J/kg
- Mixed-layer CIN
- -146 J/kg
- Mixed-layer LCL
- 678 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 68 m²/s²
- 0-3 km storm-relative helicity
- 186 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
355
ACUS11 KWNS 231959
SWOMCD
SPC MCD 231959
TXZ000-NMZ000-232130-
Mesoscale Discussion 0712
NWS Storm Prediction Center Norman OK
0259 PM CDT Sun May 23 2021
Areas affected...Southwest Texas
Concerning...Severe potential...Watch unlikely
Valid 231959Z - 232130Z
Probability of Watch Issuance...20 percent
SUMMARY...A few storms capable of large hails and severe wind gusts
possible this afternoon, watch issuance unlikely.
DISCUSSION...Convective initiation appears to be occurring over the
Davis Mountains in southwest Texas. Clear skies have allowed
temperatures to warm into the mid to upper 80s F in this area amid
dew point temperatures in the mid 50s F. Farther east, deep
southeasterly low-level flow has resulted in somewhat richer
near-surface moisture, with dew point temperatures in the low 60s F.
These conditions, combined with at least moderate low- and mid-level
lapse rates, are yielding a north-south axis of instability,
characterized by MLCAPE of 1500-2000 J/kg. Despite these
thermodynamic indices, deep-layer and low-level shear remains rather
weak.
The current expectation is for storms to continue developing over
the high terrain areas of southwest Texas and move east/southeast
with time, into the somewhat richer low-level moisture reservoir.
This evolution is supported by recent HRRR runs. Large hail and a
few severe wind gusts are possible with this activity. The lack of
appreciable flow aloft over the region should result in somewhat
disorganized convective evolution with time. Thus, watch issuance is
not anticipated, but convective trends will be monitored.
..Karstens/Guyer.. 05/23/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SJT...MAF...
LAT...LON 29980318 30230396 31110431 32090358 31920236 30430228
29980318SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 22, 8:21 PM CDT | Mesoscale Discussion | SPC | Dallas, Denton, Ellis, Johnson, Kaufman, Parker and 2 more | 54 min |
| May 23, 3:41 PM CDT | Mesoscale Discussion | SPC | Dallam, Hartley, Oldham | 94 min |
| May 23, 5:07 PM CDT | Severe Thunderstorm Watch | SPC | Dallam, Deaf Smith, Hartley, Moore, Oldham, Potter and 2 more | 7 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.