Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 707
The Storm Prediction Center issued this mesoscale discussion at May 22, 2021, 8:21 PM CDT for 8 counties in Texas. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- May 22, 2021, 8:21 PM CDT (01:21 UTC)
- Expired
- May 22, 2021, 9:15 PM CDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Dallas County, TX, Denton County, TX, Ellis County, TX, Johnson County, TX, Kaufman County, TX, Parker County, TX, Rockwall County, TX, Tarrant County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 18 km from the middle of the area, began a volume at 01:22 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
Fort Worth, TX (KFWD), launched 00:00Z, 1.4 hours before the alert went out and 22 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
- 567 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 498 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 73 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.5
The text
As transmitted.
963
ACUS11 KWNS 230121
SWOMCD
SPC MCD 230121
TXZ000-230215-
Mesoscale Discussion 0707
NWS Storm Prediction Center Norman OK
0821 PM CDT Sat May 22 2021
Areas affected...DFW Vicinity
Concerning...Severe potential...Watch unlikely
Valid 230121Z - 230215Z
Probability of Watch Issuance...5 percent
SUMMARY...A brief tornado is possible for the next 1-2 hours near
DFW. No WW is expected for this conditional, short-duration threat.
DISCUSSION...A couple of stronger updrafts have developed southeast
of the DFW metro. This activity and a somewhat favorable low-level
wind profile are associated with an MCV in central Texas. TDAL shows
around 100 m2/s2 SRH on its VWP. These showers/storms have seen
lightning activity dwindle with time, but low-level rotation has
seen a small uptick recently. While the tornado threat is still
quite low, a brief spin-up could occur within the next hour or two
before storm depth/intensity lessens with increasing low-level
stabilization.
..Wendt/Dial.. 05/23/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...
LAT...LON 33069776 33369747 32909629 32279616 31949670 32089721
32709787 33069776SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 2:59 PM CDT | Mesoscale Discussion | SPC | Crane, Ector, Loving, Pecos, Reeves, Ward and 1 more | 91 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.