Alert archive / Texas / Mesoscale Discussions in 2017
Mesoscale Discussion 975
The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2017, 4:58 PM CDT for 16 counties in Texas. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 9, 2017, 4:58 PM CDT (21:58 UTC)
- Expired
- Jun 9, 2017, 7:30 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Bandera County, TX, Blanco County, TX, Burnet County, TX, Comal County, TX, Edwards County, TX, Gillespie County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, Real County, TX, Travis County, TX, Uvalde County, TX
The radar
The Austin/San Antonio radar (KEWX), 109 km from the middle of the area, began a volume at 21:58 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
Del Rio, TX (KDLF), launched 12:00Z, 10.0 hours before the alert went out and 205 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
- 48 J/kg
- Mixed-layer CIN
- -362 J/kg
- Mixed-layer LCL
- 1646 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 171 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
791
ACUS11 KWNS 092158
SWOMCD
SPC MCD 092158
TXZ000-100030-
Mesoscale Discussion 0975
NWS Storm Prediction Center Norman OK
0458 PM CDT Fri Jun 09 2017
Areas affected...Central Texas
Concerning...Severe potential...Watch unlikely
Valid 092158Z - 100030Z
Probability of Watch Issuance...20 percent
SUMMARY...A marginal severe threat for hail and wind damage will be
possible late this afternoon into this evening across parts of
central Texas. Weather watch issuance is not expected due to the
marginal nature of the threat.
DISCUSSION...Latest surface analysis shows a very moist airmass in
place from the lower Texas coast extending northward across the
Texas Hill Country. Surface dewpoints along this corridor are in the
upper 60s and lower 70s F which is contributing to MLCAPE estimated
by the RAP to be in the 2000 to 2500 J/kg range. To the west of this
pocket of moderate instability, a vorticity max is evident on water
vapor imagery over west-central and southwest Texas. This feature
will continue to move eastward and will support a general increase
in convective coverage over the next few hours. In addition, WSR-88d
VWPs across central Texas show gradually veering winds with height
in the low to mid-levels which is resulting in 0-6 km shear in the
25 to 30 kt range according to the RAP. This combined with the
instability and steep lapse rates in the mid-levels will support a
marginal severe threat. Hail will be possible with the stronger
updrafts and a few strong wind gusts may also occur as thunderstorm
downdrafts develop and mature over the next hour or two.
..Broyles/Weiss.. 06/09/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...EWX...SJT...
LAT...LON 29699825 29349938 29350017 30100060 30740013 30879911
31369834 31049784 30259765 29699825SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 7:04 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 22 more | 56 min |
| Jun 8, 7:18 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Bailey, Briscoe, Carson, Castro, Childress and 24 more | 5 hr |
| Jun 8, 9:38 PM CDT | Mesoscale Discussion | SPC | Armstrong, Bailey, Briscoe, Castro, Childress, Collingsworth and 10 more | 67 min |
Nearby
Mesoscale Discussions in Texas, 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.