Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 795

May 19, 201720 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 19, 2017, 11:05 PM CDT for 20 counties in Texas. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
May 19, 2017, 11:05 PM CDT (04:05 UTC)
Expired
May 20, 2017, 1:00 AM CDT
In force
115 min
Issued by
the Storm Prediction Center

Counties Brown County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Eastland County, TX, Irion County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, Nolan County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Stephens County, TX, Sutton County, TX, Taylor County, TX, Tom Green County, TX

The radar

The San Angelo radar (KSJT), 49 km from the middle of the area, began a volume at 04:07 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

Midland Regional, TX (KMAF), launched 00:00Z, 4.1 hours before the alert went out and 222 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-pSkew-T log-p diagram, Midland Regional, TX at 00:00Z on 2017-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Midland Regional, TX at 00:00Z on 2017-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3843 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

518 
ACUS11 KWNS 200406
SWOMCD
SPC MCD 200405 
TXZ000-200600-

Mesoscale Discussion 0795
NWS Storm Prediction Center Norman OK
1105 PM CDT Fri May 19 2017

Areas affected...central Texas

Concerning...Tornado Watch 251...

Valid 200405Z - 200600Z

The severe weather threat for Tornado Watch 251 continues.

SUMMARY...Local severe/brief tornado risk continues with storms
ongoing across southern parts of WW 251 at this time.  Additional
storm development possible overnight.

DISCUSSION...Latest radar loop shows a band of strong/severe storms
over southern portions of watch 251 at this time, with risk for
primarily large hail indicated presently.

Latest CAM runs continue to suggest possible storm development near
the cold front, now moving across northwestern portions of the
watch.  Much of this activity may reside to the cool side of the
front however, which would suggest hail would be the primary risk
with any new storm development.  Meanwhile, possibility for locally
damaging winds or an isolated/brief tornado may persist for a couple
more hours with aforementioned activity in the southern portion of
the ww.

..Goss.. 05/20/2017

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   30520092 31310121 32510057 32779881 31239825 30479914
            30520092

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 7:15 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Fisher and 11 more60 min
May 19, 7:44 PM CDTTornado WatchSPCBrown, Callahan, Coke, Coleman, Concho, Fisher and 15 more7 hr
May 20, 7:41 AM CDTMesoscale DiscussionSPCAransas, Atascosa, Bandera, Bee, Bexar, Caldwell and 21 more94 min
May 20, 10:15 AM CDTSevere Thunderstorm WatchSPCAtascosa, Bee, Bexar, DeWitt, Dimmit, Duval and 18 more11 hr
May 20, 12:56 PM CDTMesoscale DiscussionSPCAtascosa, Bee, Bexar, DeWitt, Dimmit, Frio and 13 more94 min
May 20, 3:46 PM CDTMesoscale DiscussionSPCAtascosa, Bee, Bexar, DeWitt, Dimmit, Duval and 19 more59 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.