Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 1855
The Storm Prediction Center issued this mesoscale discussion at Oct 13, 2021, 3:59 PM CDT for 15 counties in Texas. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Oct 13, 2021, 3:59 PM CDT (20:59 UTC)
- Expired
- Oct 13, 2021, 5:30 PM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Brown County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hood County, TX, Jack County, TX, Palo Pinto County, TX, Parker County, TX, Stephens County, TX, Tarrant County, TX, Wise County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 81 km from the middle of the area, began a volume at 21:00 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
Fort Worth, TX (KFWD), launched 12:00Z, 9.0 hours before the alert went out and 89 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
- 756 J/kg
- Mixed-layer CIN
- -163 J/kg
- Mixed-layer LCL
- 834 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 310 m²/s²
- 0-3 km storm-relative helicity
- 377 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 3.2
The text
As transmitted.
507
ACUS11 KWNS 132059
SWOMCD
SPC MCD 132059
TXZ000-132230-
Mesoscale Discussion 1855
NWS Storm Prediction Center Norman OK
0359 PM CDT Wed Oct 13 2021
Areas affected...portions of North Texas
Concerning...Severe potential...Watch unlikely
Valid 132059Z - 132230Z
Probability of Watch Issuance...5 percent
SUMMARY...Storms may pose a risk for isolated damaging wind gusts or
hail into this evening. A watch is not anticipated.
DISCUSSION...Late afternoon radar imagery showed widespread showers
and thunderstorms ongoing across North Texas near a slow moving cold
front. Likely elevated given their position behind the surface
front, these storms are being supported by weak destabilization,
with SPC mesoanalysis showing 500-1000 J/kg of MUCAPE. Effective
shear remains relatively strong (40-50 kts) beneath a southwesterly
mid-level jet. This suggests some potential for organized multicells
and or an elevated supercell. Isolated hail and or a strong wind
gusts cannot be ruled out into this evening. The primarily
mitigating factor will be the limited and elevated nature of the
buoyancy. Given uncertainty on storm evolution and expected low-end
risk, a weather watch is not likely needed.
..Lyons/Mosier.. 10/13/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...SJT...
LAT...LON 31759883 31619923 31749938 32019939 32369921 33009885
33439808 33639754 33659686 33499662 33119655 32739698
32389759 32089809 31829870 31759883SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 12, 7:30 PM CDT | Mesoscale Discussion | SPC | Collingsworth, Gray, Hansford, Hemphill, Lipscomb, Ochiltree and 3 more | 2 hr |
| Oct 12, 9:18 PM CDT | Mesoscale Discussion | SPC | Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler | 117 min |
| Oct 12, 11:05 PM CDT | Tornado Watch | SPC | Childress, Collingsworth, Donley, Gray, Hall, Hemphill and 4 more | 7 hr |
| Oct 13, 1:18 AM CDT | Mesoscale Discussion | SPC | Childress, Collingsworth, Donley, Hall, Wheeler | 87 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.