Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 335
The Storm Prediction Center issued this mesoscale discussion at Apr 8, 2021, 4:58 PM CDT for 6 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 8, 2021, 4:58 PM CDT (21:58 UTC)
- Expired
- Apr 8, 2021, 7:00 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Bosque County, TX, Comanche County, TX, Coryell County, TX, Hamilton County, TX, Lampasas County, TX, Mills County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 124 km from the middle of the area, began a volume at 21:59 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, 10.0 hours before the alert went out and 147 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2501 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 0 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
177
ACUS11 KWNS 082159
SWOMCD
SPC MCD 082158
TXZ000-090000-
Mesoscale Discussion 0335
NWS Storm Prediction Center Norman OK
0458 PM CDT Thu Apr 08 2021
Areas affected...Portions of central TX
Concerning...Severe potential...Watch unlikely
Valid 082158Z - 090000Z
Probability of Watch Issuance...20 percent
SUMMARY...Thunderstorms may develop early this evening, with mainly
an isolated large hail threat. A watch is not currently expected,
but trends will be monitored.
DISCUSSION...Recent visible satellite and radar imagery show
towering cumulus developing near the intersection of a surface
dryline and warm front in central TX. Although large-scale ascent
remains nebulous across this region, there appears to be just enough
low-level convergence to support a sustained updraft. Indeed, one
cell has recently produced CG lightning flashes. Steep mid-level
lapse rates and increasing low-level moisture are supporting strong
instability across this region. A long, straight hodograph above the
boundary layer is fostering 50+ kt of deep-layer shear, which will
easily support a supercell. Isolated instances of large hail should
be the primary concern, but increasing low-level moisture and a
favorable shear profile in the 0-1 km layer suggest some potential
for surface-based storms this evening. At this point, the overall
coverage of storms appears rather uncertain, and the severe threat
may remain quite isolated. Therefore, watch issuance is not
currently expected, but radar trends will be monitored.
..Gleason/Grams.. 04/08/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...SJT...
LAT...LON 32219818 32159774 31969743 31649742 31159764 31079839
31259859 31439868 31819873 32049861 32219818SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 7, 7:00 PM CDT | Mesoscale Discussion | SPC | Newton | 60 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.