Alert archive / Texas / Mesoscale Discussions in 2015
Mesoscale Discussion 1721
The Storm Prediction Center issued this mesoscale discussion at Aug 19, 2015, 3:25 PM CDT for 20 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2015, 3:25 PM CDT (20:25 UTC)
- Expired
- Aug 19, 2015, 5:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties Bandera County, TX, Brewster County, TX, Concho County, TX, Crockett County, TX, Edwards County, TX, Gillespie County, TX, Irion County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Pecos County, TX, Presidio County, TX, Real County, TX, Schleicher County, TX, Sutton County, TX, Terrell County, TX, Val Verde County, TX
The radar
The Laughlin AFB radar (KDFX), 165 km from the middle of the area, began a volume at 20:27 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
Del Rio, TX (KDLF), launched 12:00Z, 8.4 hours before the alert went out and 113 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
- 930 J/kg
- Mixed-layer CIN
- -277 J/kg
- Mixed-layer LCL
- 1171 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- 249 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
454
ACUS11 KWNS 192025
SWOMCD
SPC MCD 192025
TXZ000-192230-
MESOSCALE DISCUSSION 1721
NWS STORM PREDICTION CENTER NORMAN OK
0325 PM CDT WED AUG 19 2015
AREAS AFFECTED...PORTIONS OF SW AND CNTRL TX
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 192025Z - 192230Z
PROBABILITY OF WATCH ISSUANCE...5 PERCENT
SUMMARY...ISOLATED SVR TSTMS MAY DEVELOP ACROSS THE AREA DURING THE
NEXT FEW HOURS AND SPREAD SWD INTO THE EVENING HOURS. WW ISSUANCE IS
UNLIKELY.
DISCUSSION...AHEAD OF A COLD FRONT DRAPED W-E ACROSS CNTRL TX...THE
AIR MASS FROM THE TX BIG BEND VICINITY TO CNTRL TX CONTINUES TO
DESTABILIZE. SFC-3-KM LAPSE RATES HAVE INCREASED TO 7.5-9.0 C/KM
AMIDST DEWPOINTS IN THE 60S SUPPORTING MLCAPE AROUND 2000-3000 J/KG.
VISIBLE SATELLITE AND MOSAIC RADAR IMAGERY INDICATE DEEPER
CONVECTIVE DEVELOPMENT UNDERWAY INVOF THE COLD FRONT...WITH TOWERING
CU NOTED IN ASSOCIATION WITH DIURNALLY ENHANCED OROGRAPHIC
CIRCULATIONS AROUND THE TX BIG BEND REGION. FURTHER DEVELOPMENT OF
THIS ACTIVITY IS ANTICIPATED DURING THE NEXT FEW HOURS. DESPITE
MODEST MID-LEVEL LAPSE RATES...SUFFICIENTLY LARGE BUOYANCY WILL
EXIST FOR A FEW INSTANCES OF SVR WIND/HAIL...WITH THE SVR-WIND
POTENTIAL AIDED BY 1000-1500 J/KG OF DCAPE. HOWEVER...LARGE-SCALE
ASCENT IS LACKING PER WATER-VAPOR IMAGERY...AND EFFECTIVE-BULK SHEAR
IS GENERALLY AOB 25 KT. THESE FACTORS WILL PREVENT A MORE
SUBSTANTIAL SVR RISK FROM EVOLVING...THOUGH ISOLATED SVR TSTMS
SPREADING SWD INTO THE EVENING WILL BE POSSIBLE.
..COHEN/CORFIDI.. 08/19/2015
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...EWX...SJT...MAF...
LAT...LON 30250441 31320103 31459937 30869880 29909871 29160063
29360113 29690175 29620256 29020294 28940330 29520441
30250441SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 8:24 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Collingsworth, Deaf Smith and 9 more | 3 hr |
| Aug 18, 11:03 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 23 more | 6 hr |
| Aug 19, 3:57 AM CDT | Mesoscale Discussion | SPC | Archer, Armstrong, Baylor, Briscoe, Castro, Childress and 20 more | 63 min |
| Aug 19, 2:45 PM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Bosque, Burnet, Cherokee, Coryell and 28 more | 3 hr |
Nearby
Mesoscale Discussions in Texas, 2015Every mesoscale discussion in 2015
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.