Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 539

May 7, 201517 counties in Oklahoma; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2015, 6:19 PM CDT for 17 counties in Oklahoma; 11 counties in Texas. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 7, 2015, 6:19 PM CDT (23:19 UTC)
Expired
May 7, 2015, 7:45 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
All 28 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Collin County, TX, Cooke County, TX, Delta County, TX, Denton County, TX, Fannin County, TX, Grayson County, TX, Hunt County, TX, Lamar County, TX, Montague County, TX, Rockwall County, TX, Wise County, TX

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.3 hours before the alert went out and 127 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, Norman, OK at 12:00Z on 2015-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Norman, OK at 12:00Z on 2015-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -72 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2333 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-72 m²/s²
0-3 km storm-relative helicity
9 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.

764 
ACUS11 KWNS 072320
SWOMCD
SPC MCD 072319 
OKZ000-TXZ000-080045-

MESOSCALE DISCUSSION 0539
NWS STORM PREDICTION CENTER NORMAN OK
0619 PM CDT THU MAY 07 2015

AREAS AFFECTED...SCNTRL TO SE OK...NCNTRL TO NE TX

CONCERNING...SEVERE THUNDERSTORM WATCH 141...

VALID 072319Z - 080045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 141
CONTINUES.

SUMMARY...A SEVERE THREAT WILL LIKELY CONTINUE FOR SEVERAL MORE
HOURS AS A LINE OF STORMS MOVES EWD INTO SE OK AND ACROSS NORTH TX.
LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT MAY OCCUR
WITH THE STRONGER CELLS AS AN MCS CONTINUES TO ORGANIZE EARLY THIS
EVENING.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A WELL-DEFINED OUTFLOW
BOUNDARY FROM NW TX EXTENDING NNEWD INTO CNTRL OK...ALONG WHICH A
LINE OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING. AHEAD OF THE
LINE...SFC DEWPOINTS ACROSS ECNTRL OK AND NE TX ARE IN THE UPPER 60S
AND LOWER 70S F...CONTRIBUTING TO MLCAPE ESTIMATED IN THE 1500 TO
2500 J/KG RANGE. IN ADDITION...THE FORT WORTH WSR-88D VWP SHOWS
VEERING WINDS WITH HEIGHT IN THE LOWEST 1 KM AND AMPLE SPEED SHEAR
MAINLY ABOVE 3 KM. THIS IS CREATING STRONG DEEP LAYER SHEAR NEAR 60
KT WHICH WILL BE FAVORABLE FOR SEVERE STORMS. THE SEVERE THREAT
SHOULD BE CONCENTRATED FROM JUST NORTH OF FORT WORTH NWD INTO ECNTRL
OK WHERE LARGE-SCALE ASCENT IS STRONGER DUE TO THE PRESENCE OF A
SUBTLE SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH
WIND DAMAGE WILL BE POSSIBLE WITH A LINE OF STORMS NEAR AND TO THE
NORTH OF THE RED RIVER...SUPERCELLS WILL CONTINUE TO DEVELOP JUST TO
THE NORTH OF FORTH WORTH. THESE ROTATING STORMS SHOULD BE CAPABLE OF
PRODUCING LARGE HAIL AND POSSIBLY A TORNADO OR TWO EARLY THIS
EVENING.

..BROYLES/MEAD.. 05/07/2015

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

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

LAT...LON   35499748 33749786 33199806 32939793 32899616 33279558
            34549540 35019562 35469621 35499748

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 8:08 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 17 more67 min
May 6, 8:51 PM CDTTornado WatchSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 26 more5 hr
May 6, 10:53 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 26 more2 hr
May 7, 1:16 AM CDTSevere Thunderstorm WatchSPCCotton, Jefferson, Love, Marshall, Tillman4 hr
May 7, 4:24 AM CDTMesoscale DiscussionSPCBryan, Carter, Cotton, Jefferson, Love, Marshall66 min
May 7, 10:20 AM CDTMesoscale DiscussionSPCComanche, Cotton, Greer, Harmon, Jackson, Kiowa and 1 more115 min
May 7, 12:52 PM CDTMesoscale DiscussionSPCBryan, Carter, Comanche, Cotton, Jefferson, Johnston and 5 more113 min
May 7, 1:10 PM CDTSevere Thunderstorm WatchSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Garvin and 10 more7 hr
May 7, 2:47 PM CDTMesoscale DiscussionSPCCimarron118 min
May 7, 3:51 PM CDTMesoscale DiscussionSPCBryan, Carter, Love, Marshall114 min
May 7, 4:33 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Coal, Johnston, Love and 3 more7 hr
May 7, 5:41 PM CDTMesoscale DiscussionSPCBrown, Callahan, Comanche, Eastland, Erath, Fisher and 7 more94 min

Nearby

Mesoscale Discussions in Oklahoma, 2015Mesoscale 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.