Alert archive / Oklahoma / Mesoscale Discussions in 2014

Mesoscale Discussion 521

May 7, 201413 counties in Oklahoma; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2014, 11:12 PM CDT for 13 counties in Oklahoma; 13 counties in Texas. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
May 7, 2014, 11:12 PM CDT (04:12 UTC)
Expired
May 8, 2014, 12:45 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 26 counties

Carter County, OK, Cleveland County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Clay County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Hood County, TX, Jack County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Stephens County, TX, Tarrant County, TX, Wise County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 107 km from the middle of the area, began a volume at 04:16 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 00:00Z, 4.2 hours before the alert went out and 129 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 00:00Z on 2014-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 976 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2014-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
976 J/kg
Mixed-layer CIN
-221 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

921 
ACUS11 KWNS 080413
SWOMCD
SPC MCD 080412 
TXZ000-OKZ000-080545-

MESOSCALE DISCUSSION 0521
NWS STORM PREDICTION CENTER NORMAN OK
1112 PM CDT WED MAY 07 2014

AREAS AFFECTED...NCNTRL TX / SRN AND CNTRL OK

CONCERNING...SEVERE THUNDERSTORM WATCH 129...

VALID 080412Z - 080545Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 129
CONTINUES.

SUMMARY...A THREAT FOR ISOLATED LARGE HAIL AND WIND DAMAGE SHOULD
CONTINUE ACROSS THE ERN PART OF WW 129 OVER THE NEXT 1 TO 2 HOURS.
THE THREAT MAY DEVELOP TO THE EAST OF THE WATCH WHERE A WATCH
EXTENSION MAY BECOME NECESSARY AFTER MIDNIGHT.

DISCUSSION...A BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS IS
LOCATED FROM NEAR LAWTON OK SWD TO JUST EAST OF ABILENE TX. ANOTHER
SUPERCELL IS MOVING INTO THE WRN PARTS OF OKLAHOMA CITY. THESE
STORMS ARE LOCATED ALONG A CORRIDOR OF MODERATE INSTABILITY WHERE
SFC DEWPOINTS ARE IN THE MID TO UPPER 60S F AND MLCAPE IS ESTIMATED
AROUND 1500 J/KG. THIS ALONG WITH INCREASING LOW-LEVEL FLOW SHOULD
HELP SUSTAIN THE STORMS FOR SEVERAL MORE HOURS AS A JET MAX NEAR 850
MB STRENGTHENS ACROSS THE SRN AND CNTRL PLAINS. MODERATE DEEP LAYER
SHEAR EVIDENT ON THE OKLAHOMA CITY AND FORT WORTH WSR-88D VWPS AND
STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR ISOLATED LARGE
HAIL ESPECIALLY WITH STORMS THAT ROTATE. A WIND DAMAGE THREAT WILL
ALSO BE POSSIBLE WITH SUPERCELLS AND SHORT LINE-SEGMENTS.

..BROYLES/THOMPSON.. 05/08/2014

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

ATTN...WFO...FWD...OUN...

LAT...LON   35459798 34509824 32779887 32319894 32149864 32539712
            35369645 35459798

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 9:38 PM CDTSevere Thunderstorm WatchSPCCaddo, Canadian, Comanche, Cotton, Grady, Jefferson and 4 more5 hr
May 8, 2:19 AM CDTMesoscale DiscussionSPCCaddo, Comanche, Cotton, Grady, Jackson, Kiowa and 1 more56 min
May 8, 3:22 PM CDTMesoscale DiscussionSPCKay113 min
May 7, 8:08 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 14 more97 min
May 8, 1:11 PM CDTMesoscale DiscussionSPCBastrop, Bell, Blanco, Bosque, Brown, Burnet and 28 more2 hr
May 8, 5:39 PM CDTSevere Thunderstorm WatchSPCBell, Blanco, Burnet, Comal, Falls, Gillespie and 9 more4 hr

Nearby

Mesoscale Discussions in Oklahoma, 2014Mesoscale Discussions in Texas, 2014Every mesoscale discussion in 2014

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.