Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 498

April 29, 201628 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2016, 12:52 PM CDT for 28 counties in Texas. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2016, 12:52 PM CDT (17:52 UTC)
Expired
Apr 29, 2016, 2:45 PM CDT
In force
113 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 28 counties

Bell County, TX, Blanco County, TX, Bosque County, TX, Brown County, TX, Burnet County, TX, Comanche County, TX, Coryell County, TX, Dallas County, TX, Ellis County, TX, Erath County, TX, Gillespie County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Johnson County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McLennan County, TX, Mills County, TX, Palo Pinto County, TX, Parker County, TX, San Saba County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Williamson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 118 km from the middle of the area, began a volume at 17:56 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.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 5.9 hours before the alert went out and 142 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, Fort Worth, TX at 12:00Z on 2016-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2369 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, Fort Worth, TX at 12:00Z on 2016-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 216 square meters per square second.193958Sfc1 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
2369 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
606 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
216 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
2.6
Supercell composite
14.9

Open this sounding in Storm Lab

The text

As transmitted.

083 
ACUS11 KWNS 291753
SWOMCD
SPC MCD 291752 
TXZ000-291945-

MESOSCALE DISCUSSION 0498
NWS STORM PREDICTION CENTER NORMAN OK
1252 PM CDT FRI APR 29 2016

AREAS AFFECTED...NORTHERN AND CENTRAL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 291752Z - 291945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...NEW THUNDERSTORM DEVELOPMENT IS EXPECTED AS ONE OR MORE
NORTH TO SOUTH ORIENTED BROKEN BANDS ACROSS CENTRAL INTO
NORTH-CENTRAL TX...GENERALLY IN VICINITY AND WEST OF THE I-35
CORRIDOR.  ALL SEVERE HAZARDS WILL BE POSSIBLE WITH SEVERE WEATHER
WATCHES LIKELY FOR THIS AFTERNOON INTO THE EVENING.

DISCUSSION...SURFACE AND OBJECTIVE ANALYSES SHOWED RICH
BOUNDARY-LAYER MOISTURE STREAMING TO THE NORTH/NORTHWEST THROUGH
CENTRAL AND NORTHERN TX WITH SURFACE DEW POINTS IN THE LOWER 70S AS
FAR NORTH AS THE DALLAS/FORT WORTH METROPLEX.  GOES-14 1-MINUTE
VISIBLE IMAGERY SHOWED CU FORMING AS N-S ORIENTED CLOUD STREETS
ACROSS THE WARM SECTOR...AS SURFACE HEATING BENEATH STEEPENING LAPSE
RATES IS RESULTING IN A VERY UNSTABLE AIR MASS /MLCAPE 2500-3000 J
PER KG/.

MOSAIC RADAR IMAGERY AND LIGHTNING DATA SHOWED ONE STORM HAD
DEVELOPED IN HAYS COUNTY TX...WITH ADDITIONAL CONVECTION BECOMING
DEEPER FARTHER WEST THROUGH NORTHWEST FROM KIMBLE TO ERATH COUNTIES
TX.  THIS LATTER CORRIDOR APPEARS TO BE OCCURRING ALONG THE LEADING
EDGE OF STRONGER FORCING FOR ASCENT APPROACHING FROM THE SOUTHERN
HIGH PLAINS SHORTWAVE TROUGH.  STRENGTHENING SLY LOW-LEVEL AND SWLY
MID-UPPER LEVEL WINDS WILL RESULT IN DEEP-LAYER SHEAR FAVORABLE FOR
SUPERCELLS.  AS THE ASCENT CONTINUES TO SPREAD EAST THIS
AFTERNOON...ADDITIONAL DEEP MOIST CONVECTION IS EXPECTED WITH ALL
SEVERE HAZARDS LIKELY GIVEN AFOREMENTIONED THERMODYNAMIC AND
KINEMATIC FIELDS.

..PETERS/THOMPSON.. 04/29/2016

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

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

LAT...LON   32929662 31179705 30089769 30059880 30419985 31289930
            32339866 33089820 33139789 32929662

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 7:52 PM CDTMesoscale DiscussionSPCBell, Brazos, Burleson, Burnet, Coryell, Falls and 7 more83 min
Apr 28, 10:31 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 30 more89 min
Apr 28, 10:54 PM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 36 more7 hr
Apr 29, 1:58 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Delta and 17 more2 hr
Apr 29, 2:59 AM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Cochran and 18 more91 min
Apr 29, 4:54 AM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Castro, Childress and 28 more66 min
Apr 29, 7:38 AM CDTMesoscale DiscussionSPCBriscoe, Cottle, Crosby, Dickens, Floyd, Foard and 10 more97 min
Apr 29, 9:46 AM CDTMesoscale DiscussionSPCBowie, Cass, Harrison, Marion, Morris89 min
Apr 29, 12:51 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Delta, Franklin, Gregg and 17 more114 min
Apr 29, 1:08 PM CDTTornado WatchSPCAnderson, Bell, Bosque, Collin, Comanche, Cooke and 35 more9 hr
Apr 29, 1:40 PM CDTMesoscale DiscussionSPCCooke, Fannin, Grayson, Wichita, Wilbarger65 min
Apr 29, 1:43 PM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more8 hr
Apr 29, 1:57 PM CDTTornado WatchSPCClay, Wichita, Wilbarger8 hr
Apr 29, 3:34 PM CDTMesoscale DiscussionSPCBell, Bosque, Collin, Cooke, Coryell, Dallas and 31 more86 min
Apr 29, 5:42 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more93 min
Apr 29, 6:16 PM CDTMesoscale DiscussionSPCCollin, Cooke, Delta, Denton, Fannin, Grayson and 3 more89 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.