Alert archive / Texas / Mesoscale Discussions in 2017
Mesoscale Discussion 482
The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2017, 9:35 PM CDT for 4 counties in Arkansas; 4 parishes in Louisiana; 50 counties in Texas. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Apr 10, 2017, 9:35 PM CDT (02:35 UTC)
- Expired
- Apr 10, 2017, 11:00 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
All 58 counties
Columbia County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Webster Parish, LA, Anderson County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Comal County, TX, Coryell County, TX, Edwards County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Gregg County, TX, Guadalupe County, TX, Harrison County, TX, Hays County, TX, Hill County, TX, Houston County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Marion County, TX, Mason County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Navarro County, TX, Panola County, TX, Real County, TX, Robertson County, TX, Rusk County, TX, Sutton County, TX, Terrell County, TX, Titus County, TX, Travis County, TX, Upshur County, TX, Val Verde County, TX, Williamson County, TX
The radar
The Ft Hood radar (KGRK), 81 km from the middle of the area, began a volume at 02:37 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Fort Worth, TX (KFWD), launched 00:00Z, 2.6 hours before the alert went out and 160 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
- 143 J/kg
- Mixed-layer CIN
- -246 J/kg
- Mixed-layer LCL
- 1066 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- 190 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.4
The text
As transmitted.
251
ACUS11 KWNS 110236
SWOMCD
SPC MCD 110235
ARZ000-LAZ000-TXZ000-110400-
Mesoscale Discussion 0482
NWS Storm Prediction Center Norman OK
0935 PM CDT Mon Apr 10 2017
Areas affected...Edwards Plateau...central to northeast TX...and
southwest AR/northwest LA
Concerning...Severe Thunderstorm Watch 139...
Valid 110235Z - 110400Z
The severe weather threat for Severe Thunderstorm Watch 139
continues.
SUMMARY...Severe-weather threat will continue across the southern
part of the Edwards Plateau into central TX through this evening and
possibly into the overnight, with a new WW and/or WW replacement
being considered for the western parts of WW 139. Farther to the
northeast, the severe-weather threat will persist into the late
evening (until around 04Z) across the Arklatex portion of WW 139.
DISCUSSION...Severe storms will remain likely with ongoing storms in
Terrell/Crockett Counties to Mason/Llano Counties to Hill/McLennan
Counties TX this evening, given the residual favorable parameter
space of moderately strong instability and effective bulk shear up
to 40-45 kt. The presence of steep midlevel lapse rates (8-9 C/km)
and sufficient moisture (precipitable water around 1.25 inches),
with the aforementioned thermodynamics and kinematics suggest large
hail and damaging winds remain severe risks. As the cold front
shifts south into the overnight, additional storms will develop with
a continued potential for severe storms.
Farther to the northeast, objective analyses indicated surface-based
inhibition is strengthening from northeast to southwest in the
Arklatex region, with a concurrent reduction in MLCAPE. Sufficient
instability remains in the short-term, given strong bulk shear for a
additional severe storms through 04Z. Beyond 04Z, overall
severe-weather threat should weaken from northeast TX into northwest
LA and southern AR.
..Peters.. 04/11/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SHV...HGX...FWD...EWX...SJT...MAF...
LAT...LON 29810222 30490224 30600103 30919899 31839760 32309669
32119629 32159499 32659526 33319497 33329446 33569359
33749313 33559291 32819299 32329337 31629470 31279506
30689609 30339621 29579757 29489902 29520044 29230076
29470117 29810222SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 10, 11:03 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bandera, Bastrop, Bell, Bexar, Blanco and 33 more | 8 hr |
| Apr 11, 2:05 AM CDT | Mesoscale Discussion | SPC | Anderson, Bandera, Bastrop, Bell, Bexar, Blanco and 54 more | 115 min |
| Apr 11, 5:23 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Bastrop, Bell, Bexar, Blanco and 48 more | 2 hr |
| Apr 11, 1:43 PM CDT | Mesoscale Discussion | SPC | Aransas, Atascosa, Bee, Bexar, Brazoria, Caldwell and 18 more | 2 hr |
Nearby
Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Louisiana, 2017Every mesoscale discussion in 2017
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.