Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 569

April 19, 201225 counties in Oklahoma; 6 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2012, 9:13 PM CDT for 25 counties in Oklahoma; 6 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Apr 19, 2012, 9:13 PM CDT (02:13 UTC)
Expired
Apr 19, 2012, 10:15 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 31 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Lincoln County, OK, Love County, OK, Marshall County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Cooke County, TX, Denton County, TX, Grayson County, TX, Jack County, TX, Montague County, TX, Wise County, TX

The radar

The Norman radar (KTLX), 134 km from the middle of the area, began a volume at 02:14 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

Norman, OK (KOUN), launched 00:00Z, 2.2 hours before the alert went out and 122 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 00:00Z on 2012-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 348 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, Norman, OK at 00:00Z on 2012-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 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
348 J/kg
Mixed-layer CIN
-164 J/kg
Mixed-layer LCL
1750 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
162 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

008 
ACUS11 KWNS 200214
SWOMCD
SPC MCD 200213
OKZ000-TXZ000-200315-

MESOSCALE DISCUSSION 0569
NWS STORM PREDICTION CENTER NORMAN OK
0913 PM CDT THU APR 19 2012

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

CONCERNING...SEVERE THUNDERSTORM WATCH 183...

VALID 200213Z - 200315Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 183
CONTINUES.

SCTD BROKEN CLUSTER OF STRONG/SEVERE STORMS --CAPABLE OF PRIMARILY
LARGE HAIL-- WILL CONTINUE TO PROGRESS EWD INVOF THE I-35 CORRIDOR
IN CNTRL OK SWD TOWARDS THE NRN PART OF THE DFW METROPLEX DURING THE
NEXT 1-2 HRS.  THERE IS UNCERTAINTY WHETHER OR NOT THE SEVERE THREAT
WILL LEAK EWD OUT OF THE EXISTING WW...AND AN AREAL EXTENSION OR NEW
WW MAY NEED TO BE CONSIDERED AS STORMS APPROACH THE ERN BOUNDS OF WW
183.

COMPOSITE SURFACE/RADAR ANALYSIS SHOWS A FRONTAL SEGMENT
ACCELERATING SEWD ACROSS WRN N-CNTRL TX TO THE STORM CLUSTER NEAR
YOUNG AND JACK COUNTIES /TX/.  ANOTHER PORTION OF THE FRONT HAS
ADVANCED SEWD ACROSS THE NRN PORTIONS OF THE WW NEAR THE OKC
METRO...ENHANCING LOW LEVEL LIFT AND AIDING IN THE FILLING-IN OF A
LINEAR CONGLOMERATION OF STORMS JUST NW OF I-44.  IN BETWEEN THE 2
AFOREMENTIONED SURFACE BOUNDARIES EXISTS A SLOW MOVING N-S ORIENTED
FRONTAL SEGMENT ACROSS SWRN OK--SERVING AS A GENESIS REGION FOR MORE
RECENT STORM DEVELOPMENT.

00Z OUN RAOB SHOWED STEEP MID-LEVEL LAPSE RATES WITH PW/S NEAR 1
INCH--RESULTING IN MODERATE CAPE /1300 J PER KG/.  STRONG FLOW AT H5
/50 KTS/ HAS ACTED TO SUPPORT SUPERCELLULAR STRUCTURE THIS
EVENING...AND HAS CONTRIBUTED TO LARGE HAIL GROWTH WITH THE MORE
ROBUST UPDRAFTS /RECENT HAIL REPORTS 1 TO 2.5 INCH IN DIAMETER/.  AS
THIS ACTIVITY MOVES EWD...A MODEST FEED OF LOW LEVEL MOISTURE WITHIN
A STRENGTHENING LOW LEVEL JET MAY ACT TO SUSTAIN A PORTION OF THESE
STORMS TO THE ERN BOUND OF WW 183--ESPECIALLY ACROSS OK WHERE THE
CAP WAS SHOWN TO BE WEAKER /PER OUN AND FWD RAOBS/.  CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED CONCERNING POSSIBLE WW AREAL
EXTENSION OR THE NEED FOR AN ADDITIONAL DOWNSTREAM WW ACROSS E-CNTRL
OK.

..SMITH.. 04/20/2012

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

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

LAT...LON   32909889 34169782 35279826 35949656 35799570 35079530
            34479561 33139676 32959717 32879831 32909889

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 7:29 PM CDTMesoscale DiscussionSPCCraig, Garfield, Kay, Major, Noble, Nowata and 6 more2 hr
Apr 19, 10:49 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cleveland, Coal, Comanche and 22 more116 min
Apr 20, 12:35 PM CDTMesoscale DiscussionSPCAngelina, Aransas, Austin, Bee, Brazoria, Calhoun and 33 more2 hr
Apr 20, 12:57 PM CDTSevere Thunderstorm WatchSPCAransas, Austin, Bastrop, Bee, Brazoria, Brazos and 43 more7 hr
Apr 20, 1:30 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 7 more2 hr
Apr 20, 2:29 PM CDTSevere Thunderstorm WatchSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 10 more5 hr
Apr 20, 3:44 PM CDTMesoscale DiscussionSPCAngelina, Austin, Brazoria, Brazos, Burleson, Chambers and 27 more91 min
Apr 20, 4:48 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Hidalgo, Kenedy, Kleberg, Nueces and 2 more57 min
Apr 20, 6:12 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 18 more93 min

Nearby

Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Texas, 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.