Alert archive / Texas / Mesoscale Discussions in 2016
Mesoscale Discussion 646
The Storm Prediction Center issued this mesoscale discussion at May 17, 2016, 11:55 PM CDT for 18 counties in Texas. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- May 17, 2016, 11:55 PM CDT (04:55 UTC)
- Expired
- May 18, 2016, 1:00 AM CDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
Counties Atascosa County, TX, Bandera County, TX, Bexar County, TX, Caldwell County, TX, Comal County, TX, Dimmit County, TX, Frio County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kinney County, TX, Maverick County, TX, Medina County, TX, Uvalde County, TX, Wilson County, TX, Zavala County, TX
The radar
The Austin/San Antonio radar (KEWX), 107 km from the middle of the area, began a volume at 04:58 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 00:00Z, 4.9 hours before the alert went out and 171 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
- 1719 J/kg
- Mixed-layer CIN
- -134 J/kg
- Mixed-layer LCL
- 1217 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 18 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.3
The text
As transmitted.
938
ACUS11 KWNS 180455
SWOMCD
SPC MCD 180455
TXZ000-180600-
MESOSCALE DISCUSSION 0646
NWS STORM PREDICTION CENTER NORMAN OK
1155 PM CDT TUE MAY 17 2016
AREAS AFFECTED...PARTS OF CNTRL TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 180455Z - 180600Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...RADAR TRENDS SHOW THE POTENTIAL FOR ISOLATED LARGE HAIL
AND STRONG WIND GUSTS WILL CONTINUE FOR AT LEAST THE NEXT 1-2 HRS
ACROSS PARTS OF CENTRAL TX. WW 180 WILL EXPIRE AT 06Z...AND RADAR
TRENDS WILL BE MONITORED FOR A POSSIBLE NEW WW.
DISCUSSION...A SUPERCELL CLUSTER OVER THE SAN ANTONIO METRO AREA
CONTINUES TO EXHIBIT THE POTENTIAL FOR LARGE HAIL AND STRONG WIND
GUSTS PER RECENT RADAR TRENDS...ALTHOUGH THE SPATIAL COVERAGE OF
THESE THREATS APPEARS TO HAVE GRADUALLY DECREASED OVER THE LAST HR.
THIS CLUSTER IS PROGRESSING IN A GENERAL ESEWD DIRECTION...AND WILL
CONTINUE TO MAINTAIN A FEED OF MOIST LOW-LEVEL AIR FROM THE ENE. THE
SLOW-MOVING NATURE OF THIS CLUSTER /ESTIMATED AROUND 20 KT/ SUGGESTS
THE THREAT WILL SLOWLY SPREAD TOWARDS THE ERN EDGE OF WW 180 BY 06Z.
OTHER STORMS DEVELOPING NEAR THE RIO GRANDE VALLEY ARE ALSO
EXHIBITING OCCASIONAL POTENTIAL FOR LARGE HAIL AND STRONG WIND
GUSTS...AND THE ENVIRONMENT IMMEDIATELY DOWNSHEAR FROM THIS
CONVECTION REMAINS RELATIVELY UNPERTURBED FROM EARLIER CONVECTION.
THE SWD MOVEMENT OF A COLD FRONT/OUTFLOW...ALONG WITH ADDITIONAL
DIURNAL COOLING...SHOULD LEAD TO A MORE RELATIVELY CONFINED AND
MARGINAL SVR THREAT OVERNIGHT...BUT TRENDS WILL CONTINUE TO BE
MONITORED FOR POSSIBLE NEW WW ISSUANCE AFTER WW 180 EXPIRES AT 06Z.
..ROGERS/THOMPSON.. 05/18/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CRP...EWX...
LAT...LON 28649762 28200028 28870072 29180100 29410088 29760056
29729984 29969896 30099823 30089774 30039733 29519723
28649762SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 17, 8:52 PM CDT | Mesoscale Discussion | SPC | Brooks, Duval, Hidalgo, Jim Hogg, Starr, Zapata | 53 min |
| May 17, 9:33 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bexar, Blanco, Comal, Dimmit and 13 more | 87 min |
| May 18, 12:09 PM CDT | Mesoscale Discussion | SPC | Brooks, Jim Hogg, Zapata | 96 min |
| May 18, 2:49 PM CDT | Mesoscale Discussion | SPC | El Paso | 2 hr |
| May 18, 5:43 PM CDT | Mesoscale Discussion | SPC | El Paso, Hudspeth, Presidio | 62 min |
Nearby
Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016
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.