Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 340

April 17, 201534 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2015, 5:02 PM CDT for 34 counties in Texas. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Apr 17, 2015, 5:02 PM CDT (22:02 UTC)
Expired
Apr 17, 2015, 6:30 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
All 34 counties

Archer County, TX, Baylor County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coke County, TX, Coleman County, TX, Comanche County, TX, Eastland County, TX, Erath County, TX, Fisher County, TX, Hamilton County, TX, Haskell County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Knox County, TX, Mills County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 22 km from the middle of the area, began a volume at 22:04 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

Fort Worth, TX (KFWD), launched 12:00Z, 10.0 hours before the alert went out and 172 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 2015-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 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 2015-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 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
107 J/kg
Mixed-layer CIN
-344 J/kg
Mixed-layer LCL
910 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

557 
ACUS11 KWNS 172203
SWOMCD
SPC MCD 172202 
TXZ000-OKZ000-172330-

MESOSCALE DISCUSSION 0340
NWS STORM PREDICTION CENTER NORMAN OK
0502 PM CDT FRI APR 17 2015

AREAS AFFECTED...W-CNTRL/NW/N-CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 67...

VALID 172202Z - 172330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 67
CONTINUES.

SUMMARY...A RISK FOR ISOLATED SEVERE HAIL MAY PERSIST THROUGH ABOUT
00-01Z WITH BOTH A LEADING TSTM CLUSTER APPROACHING THE METROPLEX
AND REDEVELOPMENT ALONG THE DRYLINE OVER THE CONCHO VALLEY. OVERALL
THREAT MAY REMAIN TOO MARGINAL FOR AN ADDITIONAL WW ISSUANCE.

DISCUSSION...LEAD TSTM CLUSTER OVER N-CNTRL TX IS GRADUALLY EVOLVING
EWD WITHIN A MODEST LOW/MID-LEVEL SHEAR ENVIRONMENT AND
VEER-BACK-VEER WIND PROFILE SAMPLED IN FWS VWP DATA. AMIDST WEAK
BUOYANCY...CONVECTION WILL PROBABLY STRUGGLE TO FURTHER INTENSIFY
WITH MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS AS THE
MAIN HAZARDS. FARTHER SW TOWARDS THE CONCHO VALLEY...INITIAL
REDEVELOPMENT WEAKENED ABOUT HALF-HOUR AFTER INITIATION FROM NOLAN
TO STERLING COUNTIES. OUTFLOW-INDUCED CONVERGENCE ALONG THE DRYLINE
WILL REMAIN PRONOUNCED FOR A COUPLE MORE HOURS. BUT THIS REGION WILL
LIE IN BETWEEN MID-LEVEL IMPULSES AND ASSOCIATED SPEED MAXIMA
CURLING FROM ERN NM INTO CO AND THE OTHER FROM CHIHUAHUA TOWARDS S
TX. GIVEN A DOWNSTREAM CONVECTIVELY-OVERTURNED AIR MASS...TSTMS WILL
LIKELY STRUGGLE TO MAINTAIN ORGANIZED UPDRAFTS INTO MID-EVENING.

..GRAMS.. 04/17/2015

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

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

LAT...LON   31860103 32930027 33799973 33979776 33839732 32989709
            32019733 31679761 31489857 31340042 31380056 31860103

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, 1:10 AM CDTMesoscale DiscussionSPCBorden, Childress, Cottle, Crosby, Dawson, Dickens and 13 more95 min
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, 5:41 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.