Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 948

May 28, 201213 counties in Oklahoma; 24 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2012, 7:44 PM CDT for 13 counties in Oklahoma; 24 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
May 28, 2012, 7:44 PM CDT (00:44 UTC)
Expired
May 28, 2012, 9:15 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 37 counties

Bryan County, OK, Carter County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Okfuskee County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Bosque County, TX, Brown County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Dallas County, TX, Denton County, TX, Ellis County, TX, Erath County, TX, Grayson County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Johnson County, TX, McCulloch County, TX, Mills County, TX, Parker County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Tom Green County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 69 km from the middle of the area, began a volume at 00:46 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, 0.7 hours before the alert went out and 49 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 2012-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1125 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 00:00Z on 2012-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
1125 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1953 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

426 
ACUS11 KWNS 290044
SWOMCD
SPC MCD 290044 
TXZ000-OKZ000-290215-

MESOSCALE DISCUSSION 0948
NWS STORM PREDICTION CENTER NORMAN OK
0744 PM CDT MON MAY 28 2012

AREAS AFFECTED...CNTRL/N-CNTRL TX...CNTRL OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 290044Z - 290215Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ONGOING TSTMS ARE EXPECTED TO CONTINUE MOVING EWD AND A
NEW WW OR WATCH EXTENSIONS MAY BE NEEDED DOWNSTREAM. PRIMARY SEVERE
THREATS WOULD BE LARGE HAIL AND DAMAGING WINDS.

DISCUSSION...ONGOING TSTM ACTIVITY ACROSS W/NW TX IS BECOMING MORE
LINEAR AND WILL LIKELY BECOME A SEWD PROGRESSING MCS DURING THE NEXT
HOUR OR SO. OUN AND FWD 00Z SOUNDING INDICATE NEAR 3000 J/KG SBCAPE
WILL NO CINH. SFC TEMPERATURES REMAIN IN THE UPPER 80S TO LOW 90S
WITH DEWPOINTS IN THE MID 60S ACROSS CNTRL/N-CNTRL TX AND CNTRL OK.
30 TO 35 KT NWLY EFFECTIVE SHEAR VECTORS...LATEST RADAR
IMAGERY...AND HIGH-RESOLUTION MODEL GUIDANCE ALL SUGGEST LINEAR
ORGANIZATION OF A SEWD PROGRESSING MCS IS LIKELY. STEEP LAPSE RATES
SHOULD CONTINUE TO PROMOTE A HAIL THREAT IN ADDITION TO THE STRONG
WIND THREAT ASSOCIATED WITH AN ORGANIZED MCS. WEAK LOW-LEVEL SHEAR
AND INCREASING SBCINH ASSOCIATED WITH THE LOSS OF DAYTIME HEATING
SHOULD KEEP THE OVERALL TORNADO THREAT LOW...ALTHOUGH A FEW STRONG
CIRCULATIONS EMBEDDED IN THE LINE MAY PRODUCE A BRIEF TORNADO.

FARTHER N /ACROSS CNTRL OK/...TSTM HAVE INITIATED ON AN OUTFLOW
BOUNDARY FROM THE TSTMS NEAR THE RED RIVER. PREDOMINATELY
UNIDIRECTIONAL DEEP LAYER FLOW AND SBCAPE GREATER THAN 3000 J/KG
OBSERVED ON THE 00Z OUN SOUNDING SUGGESTS SPLITTING STORMS WILL
CONTINUE WILL THE POTENTIAL FOR LARGE HAIL.

..MOSIER/HART.. 05/29/2012

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

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

LAT...LON   31599738 31020028 31490061 32189872 33629739 34729737
            35569699 35549627 34399607 32299640 31599738

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 9:51 PM CDTMesoscale DiscussionSPCCanadian, Creek, Kingfisher, Lincoln, Logan, Oklahoma and 2 more54 min
May 28, 11:06 PM CDTMesoscale DiscussionSPCCraig, Nowata, Osage, Ottawa, Washington54 min
May 29, 3:06 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Blaine, Caddo, Canadian, Cleveland and 28 more84 min
May 29, 3:55 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Atoka, Blaine, Bryan, Caddo, Canadian and 38 more12 hr
May 29, 6:47 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 31 more88 min
May 28, 9:35 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Cooke, Denton and 16 more55 min
May 28, 11:25 PM CDTMesoscale DiscussionSPCBosque, Brown, Coleman, Coryell, Dallas, Ellis and 10 more35 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion in 2012

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.