Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 321

April 16, 201590 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2015, 6:19 PM CDT for 90 counties in Texas. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
Apr 16, 2015, 6:19 PM CDT (23:19 UTC)
Expired
Apr 16, 2015, 7:45 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
All 90 counties

Anderson County, TX, Aransas County, TX, Austin County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Bosque County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Calhoun County, TX, Chambers County, TX, Cherokee County, TX, Collin County, TX, Colorado County, TX, Comal County, TX, Comanche County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, DeWitt County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Fannin County, TX, Fayette County, TX, Fort Bend County, TX, Freestone County, TX, Galveston County, TX, Gillespie County, TX, Goliad County, TX, Gonzales County, TX, Grayson County, TX, Grimes County, TX, Guadalupe County, TX, Hamilton County, TX, Hardin County, TX, Harris County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Houston County, TX, Hunt County, TX, Jack County, TX, Jackson County, TX, Johnson County, TX, Karnes County, TX, Kaufman County, TX, Kendall County, TX, Lampasas County, TX, Lavaca County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Matagorda County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Montague County, TX, Montgomery County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Polk County, TX, Rains County, TX, Refugio County, TX, Robertson County, TX, Rockwall County, TX, San Jacinto County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Trinity County, TX, Van Zandt County, TX, Victoria County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX, Wilson County, TX, Wise County, TX

The radar

The Ft Hood radar (KGRK), 70 km from the middle of the area, began a volume at 23:18 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, 11.3 hours before the alert went out and 198 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 2015-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 521 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 2015-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 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
521 J/kg
Mixed-layer CIN
-142 J/kg
Mixed-layer LCL
884 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

338 
ACUS11 KWNS 162320
SWOMCD
SPC MCD 162319 
TXZ000-OKZ000-170045-

MESOSCALE DISCUSSION 0321
NWS STORM PREDICTION CENTER NORMAN OK
0619 PM CDT THU APR 16 2015

AREAS AFFECTED...CENTRAL AND EASTERN TEXAS

CONCERNING...SEVERE THUNDERSTORM WATCH 60...

VALID 162319Z - 170045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 60
CONTINUES.

SUMMARY...STORMS MAY CONGEAL INTO A COMPLEX WITH EASTWARD
PROGRESSION THROUGH THE EVENING...POSING LARGE HAIL AND DAMAGING
WIND THREATS.

DISCUSSION...SEVERE THREAT CONTINUES ACROSS WW 60...WITH NUMEROUS
STORMS LOCATED FROM NEAR BAZ NORTHWARD TO WEST OF PRX AND EASTWARD
TO NEAR BTW. THESE STORMS MAY CONGEAL INTO ONE OR TWO CONVECTIVE
COMPLEXES IN THE NEXT FEW HOURS AS THEY DEVELOP COLD POOLS AND MOVE
EASTWARD AT ABOUT 20 KNOTS. GIVEN THE MODERATE INSTABILITY AND DEEP
LAYER SHEAR IN PLACE...LARGE HAIL AND DAMAGING WIND GUSTS WILL
REMAIN THE GREATEST THREATS. ADDITIONALLY...AN ISOLATED TORNADO
THREAT EXISTS WITH A SUPERCELL MOVING EASTWARD ACROSS
JACKSON...MATAGORDA...AND BRAZORIA COUNTIES IN THE NEXT 1-2 HOURS.

..COOK/COHEN/CORFIDI.. 04/16/2015

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

ATTN...WFO...LCH...SHV...HGX...FWD...OUN...CRP...EWX...SJT...

LAT...LON   29349888 29939911 30579897 31509868 32599864 33469834
            33959770 33899635 33869589 33089560 32209540 31309478
            30979449 30109428 29579431 28869531 28389637 27969708
            29349888

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 12:49 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Castro, Crosby, Donley and 15 more116 min
Apr 16, 1:34 PM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Bexar, Blanco, Bosque and 48 more116 min
Apr 16, 1:48 PM CDTTornado WatchSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hansford and 8 more8 hr
Apr 16, 2:22 PM CDTSevere Thunderstorm WatchSPCAnderson, Aransas, Austin, Bastrop, Bee, Bell and 81 more8 hr
Apr 16, 2:42 PM CDTMesoscale DiscussionSPCAnderson, Aransas, Austin, Bastrop, Bee, Bell and 75 more63 min
Apr 16, 4:06 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Brown, Callahan, Childress and 46 more2 hr
Apr 16, 4:40 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Briscoe, Brown, Callahan, Castro and 45 more7 hr
Apr 16, 4:59 PM CDTMesoscale DiscussionSPCAngelina, Cherokee, Gregg, Hardin, Houston, Jasper and 12 more91 min
Apr 16, 5:06 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hansford and 7 more84 min
Apr 16, 5:29 PM CDTMesoscale DiscussionSPCBailey, Dallam, Deaf Smith, Hartley, Oldham, Parmer91 min

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.