Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 385
The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2021, 5:27 PM CDT for 18 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 14, 2021, 5:27 PM CDT (22:27 UTC)
- Expired
- Apr 14, 2021, 7:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 95
Counties Aransas County, TX, Bee County, TX, Brazoria County, TX, Calhoun County, TX, Chambers County, TX, DeWitt County, TX, Fort Bend County, TX, Galveston County, TX, Goliad County, TX, Harris County, TX, Jackson County, TX, Jefferson County, TX, Karnes County, TX, Lavaca County, TX, Matagorda County, TX, Refugio County, TX, Victoria County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 108 km from the middle of the area, began a volume at 22:27 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
Corpus Christi, TX (KCRP), launched 12:00Z, 10.5 hours before the alert went out and 191 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
- 2595 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 477 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 152 m²/s²
- Significant tornado parameter
- 1.1
- Supercell composite
- 6.0
The text
As transmitted.
796
ACUS11 KWNS 142227
SWOMCD
SPC MCD 142227
LAZ000-TXZ000-150030-
Mesoscale Discussion 0385
NWS Storm Prediction Center Norman OK
0527 PM CDT Wed Apr 14 2021
Areas affected...Portions of the Louisiana and Texas Coastline
Concerning...Severe Thunderstorm Watch 95...
Valid 142227Z - 150030Z
The severe weather threat for Severe Thunderstorm Watch 95
continues.
SUMMARY...A limited threat for severe storms will remain in place
for a couple more hours. Large hail would be the primary threat for
any storms that manage to develop.
DISCUSSION...A surface cold front is currently meandering along the
east-TX coastline, with temperatures in the 80s F and dewpoints
exceeding 70 F ahead of the front. Steep (8+ C/km) mid-level lapse
rates overspreading the warm, moist low-level airmass have promoted
3000-4000 J/kg MLCAPE (per latest Mesoanalysis and RAP forecast
soundings). Despite the favorable thermodynamic environment in
place, along with 35+ kts of effective bulk shear, very limited
deep-layer ascent has precluded a more robust severe threat thus
far. Given that afternoon peak heating is underway, it appears that
low-level lift due to diurnal mixing is insufficient for promoting
organized storms/a severe threat. Some upper support is evident via
the eastward propagation of a small mid-level impulse across
northwest TX, however, it is unclear if the upper support will
influence an uptick in convective development across southeast
Texas.
Should storms manage to develop and mature in close proximity to the
front, especially towards the BEA/VCT vicinity, large hail would
become a concern given the steep lapse rates in place. Conditions
will continue to be monitored for more rigorous convective
development.
..Squitieri.. 04/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LCH...HGX...CRP...EWX...
LAT...LON 27839716 28249789 28669810 29029778 29489684 30029529
30209403 30029377 29579389 28989501 28549588 27839716SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 14, 5:17 AM CDT | Mesoscale Discussion | SPC | Angelina, Hardin, Jasper, Liberty, Montgomery, Nacogdoches and 9 more | 2 hr |
| Apr 14, 12:43 PM CDT | Mesoscale Discussion | SPC | Bee, Colorado, DeWitt, Fort Bend, Goliad, Gonzales and 8 more | 2 hr |
| Apr 14, 1:40 PM CDT | Severe Thunderstorm Watch | SPC | Aransas, Bee, Brazoria, Calhoun, Chambers, Fort Bend and 10 more | 6 hr |
| Apr 14, 4:49 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Callahan, Clay, Eastland, Jack and 8 more | 116 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.