Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 331

April 17, 201519 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2015, 1:10 AM CDT for 19 counties in Texas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 17, 2015, 1:10 AM CDT (06:10 UTC)
Expired
Apr 17, 2015, 2:45 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Borden County, TX, Childress County, TX, Cottle County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Floyd County, TX, Gaines County, TX, Garza County, TX, Hall County, TX, Howard County, TX, Kent County, TX, King County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Scurry County, TX, Stonewall County, TX, Terry County, TX

The radar

The Lubbock radar (KLBB), 77 km from the middle of the area, began a volume at 06:14 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 6.2 hours before the alert went out and 187 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, Amarillo Airport, TX at 00:00Z on 2015-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 301 joules per kilogram.LCLLFCEL10008507005003002001001 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, Amarillo Airport, TX at 00:00Z on 2015-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.19395878Sfc1 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
301 J/kg
Mixed-layer CIN
-116 J/kg
Mixed-layer LCL
1659 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

103 
ACUS11 KWNS 170611
SWOMCD
SPC MCD 170610 
TXZ000-170745-

MESOSCALE DISCUSSION 0331
NWS STORM PREDICTION CENTER NORMAN OK
0110 AM CDT FRI APR 17 2015

AREAS AFFECTED...WEST TX/TX SOUTH PLAINS

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 170610Z - 170745Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED INSTANCES OF SEVERE HAIL WILL BE POSSIBLE
OVERNIGHT AS STORMS SPREAD EAST-NORTHEASTWARD ACROSS FAR WEST TX/TX
SOUTH PLAINS. CURRENT THINKING IS THAT THE RELATIVELY
MARGINAL/ISOLATED NATURE OF THE HAIL RISK WILL PRECLUDE A WATCH
ISSUANCE.

DISCUSSION...STORMS HAVE INCREASED ACROSS THE SOUTHERN/EASTERN TX
PANHANDLE SOUTH-SOUTHWESTWARD INTO WEST TX/TX SOUTH PLAINS INCLUDING
AREAS NEAR/NORTHEAST OF LUBBOCK...WITH ADDITIONAL/MORE ISOLATED
STORM DEVELOPMENT ALSO NOTED FARTHER SOUTHWEST NEAR THE TX/NM BORDER
EAST OF HOBBS NM. WITH A SURFACE LOW NOTED JUST W/NW OF
MIDLAND...THESE STORMS ARE OCCURRING IMMEDIATELY BEHIND AN
OUTFLOW-INFLUENCED EASTWARD-SHIFTING BOUNDARY THAT EXTENDS
NORTHEASTWARD INTO THE EASTERN TX PANHANDLE. BOUNDARY-RELATED UPLIFT
ASIDE...THE RECENT UPSWING IN CONVECTIVE DEVELOPMENT MAY BE ENHANCED
BY A SUBTLE UPSTREAM SHORTWAVE TROUGH/MID-LEVEL SPEED MAXIMUM ON THE
EASTERN PERIPHERY OF THE FOUR CORNERS AREA-CENTERED UPPER LOW AS PER
WATER VAPOR IMAGERY/REGIONAL WSR-88D VWP DATA. THIS SPEED MAXIMUM
MAY CONTRIBUTE TO SOME ADDITIONAL STRENGTHENING OF DEEP-LAYER WIND
SHEAR...WITH REGIONAL VWP DATA CONSISTENT WITH AROUND 35-40 KT OF
EFFECTIVE SHEAR. REGARDLESS...EVEN WHILE THE BOUNDARY LAYER
CONTINUES TO COOL...RELATIVELY STEEP MID-LEVEL LAPSE RATES/MODERATE
ELEVATED BUOYANCY...AS PER 00Z SOUNDING DATA FROM MIDLAND...WILL
SUPPORT ISOLATED SEVERE HAIL POTENTIAL THROUGH THE EARLY/MIDDLE PART
OF THE OVERNIGHT HOURS.

..GUYER/EDWARDS.. 04/17/2015

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

ATTN...WFO...OUN...SJT...LUB...MAF...

LAT...LON   34640017 33609975 32140134 32850298 34070149 34640017

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 7:08 PM CDTMesoscale DiscussionSPCCollingsworth, Wheeler2 hr
Apr 16, 7:16 PM CDTMesoscale DiscussionSPCArcher, Baylor, Briscoe, Brown, Callahan, Childress and 41 more89 min
Apr 16, 7:44 PM CDTMesoscale DiscussionSPCDallam, Hansford, Sherman61 min
Apr 16, 8:20 PM CDTMesoscale DiscussionSPCBrazoria, Chambers, Colorado, Fort Bend, Galveston, Harris and 2 more85 min
Apr 16, 8:36 PM CDTTornado WatchSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 10 more3 hr
Apr 16, 10:20 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Borden, Briscoe, Carson, Castro and 32 more2 hr
Apr 16, 11:33 PM CDTMesoscale DiscussionSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 6 more87 min
Apr 16, 11:59 PM CDTSevere Thunderstorm WatchSPCCollingsworth, Donley, Gray, Hemphill, Roberts, Wheeler5 hr
Apr 17, 2:02 AM CDTMesoscale DiscussionSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Roberts and 1 more88 min
Apr 17, 4:43 AM CDTMesoscale DiscussionSPCHardeman62 min
Apr 17, 10:26 AM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Burnet, Comal, Edwards and 12 more2 hr
Apr 17, 10:55 AM CDTMesoscale DiscussionSPCBaylor, Brown, Callahan, Coke, Coleman, Concho and 15 more2 hr
Apr 17, 11:53 AM CDTSevere Thunderstorm WatchSPCArcher, Atascosa, Bandera, Baylor, Bee, Bell and 73 more7 hr
Apr 17, 1:31 PM CDTMesoscale DiscussionSPCAtascosa, Bee, Calhoun, DeWitt, Dimmit, Frio and 12 more89 min
Apr 17, 3:06 PM CDTMesoscale DiscussionSPCBriscoe, Carson, Childress, Collingsworth, Donley, Gray and 8 more84 min
Apr 17, 3:22 PM CDTMesoscale DiscussionSPCAransas, Bee, Brazoria, Calhoun, Colorado, DeWitt and 11 more113 min
Apr 17, 3:30 PM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Austin, Bastrop, Brazoria, Brazos and 30 more6 hr
Apr 17, 5:02 PM CDTMesoscale DiscussionSPCArcher, Baylor, Bosque, Brown, Callahan, Clay and 28 more88 min
Apr 17, 5:41 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brazoria, Brooks, Calhoun and 26 more94 min
Apr 17, 6:57 PM CDTTornado WatchSPCAransas, Bee, Brooks, Calhoun, Duval, Goliad and 16 more5 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.