Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 554

May 8, 201513 counties in Oklahoma; 21 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2015, 6:50 PM CDT for 13 counties in Oklahoma; 21 counties in Texas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
May 8, 2015, 6:50 PM CDT (23:50 UTC)
Expired
May 8, 2015, 8:15 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 34 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Garvin County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pontotoc County, OK, Pushmataha County, OK, Archer County, TX, Clay County, TX, Collin County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Fannin County, TX, Grayson County, TX, Hopkins County, TX, Hunt County, TX, Jack County, TX, Lamar County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Tarrant County, TX, Wise County, TX, Young County, TX

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, 11.8 hours before the alert went out and 82 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 2015-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1443 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 2015-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 224 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
1443 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
613 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
224 m²/s²
0-3 km storm-relative helicity
128 m²/s²
Significant tornado parameter
1.1
Supercell composite
10.6

Open this sounding in Storm Lab

The text

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

219 
ACUS11 KWNS 082351
SWOMCD
SPC MCD 082350 
OKZ000-TXZ000-090115-

MESOSCALE DISCUSSION 0554
NWS STORM PREDICTION CENTER NORMAN OK
0650 PM CDT FRI MAY 08 2015

AREAS AFFECTED...SRN OK...NORTH TX

CONCERNING...TORNADO WATCH 143...

VALID 082350Z - 090115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 143 CONTINUES.

SUMMARY...A SEVERE THREAT IS EXPECTED TO CONTINUE ACROSS NCNTRL TX
AND SCNTRL OK. THE THREAT SHOULD GRADUALLY DEVELOP EWD INTO SE OK
AND NE TX OVER THE NEXT FEW HOURS. A TORNADO THREAT ALONG WITH
POTENTIAL FOR WIND DAMAGE AND LARGE HAIL WILL EXIST WITH THE MORE
INTENSE STORMS. A REPLACEMENT WATCH WILL BE REQUIRED BEFORE 02Z.

DISCUSSION...THE LATEST RADAR IMAGERY SHOWS SEVERAL CLUSTERS OF
STRONG TO SEVERE STORMS FROM CNTRL OK SWWD INTO NW TX AND
THUNDERSTORMS ASSOCIATED WITH WARM ADVECTION ALSO DEVELOPING ACROSS
NORTH TX AND SRN OK. SFC DEWPOINTS IN SRN OK AND NORTH TX ARE IN THE
LOWER 70S F...CONTRIBUTING TO MLCAPE IN THE 2500 TO 3000 J/KG. IN
ADDITION TO THE MODERATE INSTABILITY...THE FORT WORTH WSR-88D VWP
SHOWS DIRECTIONAL SHEAR IN THE LOW TO MID-LEVELS WITH STRONG SPEED
SHEAR ABOVE 4 KM...CREATING 50 KT OF 0-6 KM SHEAR. BOUNDARY-LAYER
SHEAR SHOULD INCREASE SOME THIS EVENING AS A 35 TO 45 KT LOW-LEVEL
JET STRENGTHENS ACROSS NCNTRL TX. THIS SHOULD BE FAVORABLE FOR
TORNADOES WITH THE MORE DOMINANT SUPERCELLS. STORMS THAT ROTATE
SHOULD ALSO CONTAIN A THREAT FOR LARGE HAIL AND WIND DAMAGE. THE
WIND DAMAGE THREAT MAY BECOME ENHANCED WITH BOWING LINE-SEGMENTS.

..BROYLES/MEAD.. 05/08/2015

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

ATTN...WFO...SHV...TSA...FWD...OUN...SJT...

LAT...LON   32719567 32699699 32649844 33019906 33469903 34029825
            34829747 34959624 34569485 32719567

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 8:49 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Pushmataha86 min
May 7, 11:05 PM CDTMesoscale DiscussionSPCChoctaw, McCurtain, Pushmataha85 min
May 8, 12:22 PM CDTMesoscale DiscussionSPCCaddo, Comanche, Cotton, Greer, Harmon, Jackson and 4 more83 min
May 8, 12:51 PM CDTTornado WatchSPCBeckham, Caddo, Canadian, Carter, Cleveland, Comanche and 22 more8 hr
May 8, 2:12 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cleveland, Coal, Comanche and 22 more93 min
May 8, 3:45 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cleveland, Comanche, Cotton and 11 more90 min
May 8, 5:24 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Creek, Delaware, Haskell and 15 more96 min
May 8, 8:57 AM CDTMesoscale DiscussionSPCBailey, Briscoe, Castro, Childress, Cottle, Crosby and 18 more93 min
May 8, 9:31 AM CDTTornado WatchSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Callahan and 40 more7 hr
May 8, 2:48 PM CDTMesoscale DiscussionSPCBailey, Borden, Cottle, Crosby, Dawson, Dickens and 18 more87 min
May 8, 3:26 PM CDTMesoscale DiscussionSPCCoke, Crockett, Edwards, Glasscock, Irion, Kinney and 8 more94 min
May 8, 3:50 PM CDTTornado WatchSPCAndrews, Borden, Callahan, Coke, Crane, Crockett and 27 more8 hr
May 8, 5:15 PM CDTMesoscale DiscussionSPCBell, Brazos, Burleson, Falls, Freestone, Grimes and 8 more90 min
May 8, 6:13 PM CDTMesoscale DiscussionSPCBaylor, Borden, Callahan, Coke, Concho, Crane and 31 more2 hr

Nearby

Mesoscale Discussions in Texas, 2015Mesoscale Discussions in Oklahoma, 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.