Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 641

May 17, 201614 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 17, 2016, 1:52 PM CDT for 14 counties in Texas. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued: May 17, 2016, 1:52 PM CDT (18:52 UTC)
Expired: May 17, 2016, 3:45 PM CDT
In force: 113 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Bandera County, TX, Crane County, TX, Crockett County, TX, Edwards County, TX, Irion County, TX, Kerr County, TX, Kimble County, TX, Reagan County, TX, Real County, TX, Schleicher County, TX, Sutton County, TX, Upton County, TX, Uvalde County, TX, Val Verde County, TX

The radar

The San Angelo radar (KSJT), 101 km from the middle of the area, began a volume at 18:54 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.

Severe Thunderstorm Watch 180May 17, 2:25 PM CDT

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 6.9 hours before the alert went out and 133 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 38 J/kg
Mixed-layer CIN: -561 J/kg
Mixed-layer LCL: 2197 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -57 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

760 
ACUS11 KWNS 171852
SWOMCD
SPC MCD 171852 
TXZ000-172045-

MESOSCALE DISCUSSION 0641
NWS STORM PREDICTION CENTER NORMAN OK
0152 PM CDT TUE MAY 17 2016

AREAS AFFECTED...LOWER PECOS VALLEY TO EDWARDS PLATEAU

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 171852Z - 172045Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A FEW STORMS FORMING WITHIN OVER THE LOWER PECOS VALLEY
SHOULD STRENGTHEN WITH A PRIMARY RISK OF LARGE HAIL. THIS THREAT MAY
BE RELATIVELY CONFINED SHORT-TERM WITHIN THIS REGION BEFORE
INCREASING DOWNSTREAM TOWARDS EARLY EVENING.

DISCUSSION...SURFACE-BASED STORM INITIATION IS UNDERWAY ALONG THE
SLOW-MOVING COLD FRONT ACROSS THE LOWER PECOS VALLEY. THE AIR MASS
WITHIN THIS AREA AND THE CONCHO VALLEY APPEARS TO BE MODERATELY
UNSTABLE WITH MLCAPE NEAR 1500-2000 J/KG. GIVEN SUBSTANTIAL VEERING
OF THE WIND PROFILE WITH HEIGHT ALONG WITH STEEP MID-LEVEL LAPSE
RATES...A COUPLE SUPERCELLS SHOULD DEVELOP DURING THE NEXT COUPLE
HOURS WITH A PRIMARY RISK OF LARGE HAIL. DOWNSTREAM OVER THE EASTERN
EDWARDS PLATEAU TO HILL COUNTRY...ELEVATED CONVECTION NORTH OF 
LARGE-SCALE CONVECTIVE OUTFLOW THAT RIPPLED SOUTHWARD HAS LIMITED
SURFACE-BASED DESTABILIZATION. THIS SHOULD RESULT IN THE SEVERE
THREAT BEING SPATIALLY CONFINED THROUGH LATE AFTERNOON.

..GRAMS/GOSS.. 05/17/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...EWX...SJT...MAF...

LAT...LON   31440258 31720229 31670183 31500122 31090031 30589960
            29879916 29379934 29199973 29310017 29410069 30350177
            30940237 31440258

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 16, 7:23 PM CDT	Mesoscale Discussion	SPC	Carson, Collingsworth, Gray, Hansford, Hartley, Hemphill and 7 more	67 min
May 16, 11:58 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Briscoe, Childress, Clay, Cottle and 7 more	5 hr
May 17, 2:08 AM CDT	Mesoscale Discussion	SPC	Clay, Cooke, Foard, Hardeman, Montague, Wichita and 1 more	2 hr
May 17, 2:25 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bexar, Blanco, Brewster, Comal and 34 more	13 hr
May 17, 5:18 PM CDT	Mesoscale Discussion	SPC	Bee, Duval, Jim Wells, Live Oak, Webb	57 min
May 17, 5:38 PM CDT	Mesoscale Discussion	SPC	Bandera, Crockett, Dimmit, Edwards, Frio, Gillespie and 17 more	97 min
May 17, 6:20 PM CDT	Severe Thunderstorm Watch	SPC	Brooks, Duval, Hidalgo, Jim Hogg, La Salle, McMullen and 3 more	5 hr

Nearby

Mesoscale Discussions in Texas, 2016 Every 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.