Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 974

May 29, 201223 counties in Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 29, 2012, 11:28 PM CDT for 23 counties in Oklahoma; 5 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
May 29, 2012, 11:28 PM CDT (04:28 UTC)
Expired
May 30, 2012, 12:30 AM CDT
In force
62 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, Comanche County, OK, Garvin County, OK, Grady County, OK, Haskell County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, McClain County, OK, McCurtain County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Stephens County, OK, Cooke County, TX, Fannin County, TX, Grayson County, TX, Lamar County, TX, Montague County, TX

The radar

The Norman radar (KTLX), 122 km from the middle of the area, began a volume at 04:28 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.5 hours before the alert went out and 123 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 2012-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2199 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 2012-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 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
2199 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1607 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.5
Supercell composite
6.2

Open this sounding in Storm Lab

The text

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

907 
ACUS11 KWNS 300429
SWOMCD
SPC MCD 300428
ARZ000-OKZ000-TXZ000-300530-

MESOSCALE DISCUSSION 0974
NWS STORM PREDICTION CENTER NORMAN OK
1128 PM CDT TUE MAY 29 2012

AREAS AFFECTED...SRN OK...NCNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 319...

VALID 300428Z - 300530Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 319
CONTINUES.

SUMMARY...OVERALL THREAT HAS TRANSITIONED TO DAMAGING WIND...BUT
HAIL REMAINS POSSIBLE WITHIN THE STRONGER CORES. PRIMARY THREAT WILL
EXIST OVER SRN OK NEXT HOUR OR TWO AND WILL REMAIN CONFINED TO WW
319 AND REMAINING PORTION OF WW 317. SOME WEAKENING MIGHT OCCUR AS
STORMS APPROACH THE RED RIVER...AND WW ISSUANCE FARTHER SOUTH OVER
NCNTRL TX WILL ULTIMATELY DEPEND ON CONVECTIVE TRENDS.

DISCUSSION...STORMS HAVE CONSOLIDATED INTO A FORWARD PROPAGATING MCS
AND WILL CONTINUE TO POSE A THREAT FOR DAMAGING WIND AS THEY MOVE
THROUGH SRN OK NEXT HOUR OR TWO. ISOLATED LARGE HAIL WILL ALSO BE
POSSIBLE WITHIN THE STRONGER CORES. ATMOSPHERE OVER NCNTRL TX HAS
NOT BEEN OVERTURNED AND REMAINS MODERATELY UNSTABLE.
HOWEVER...CONVECTIVE INHIBITION IS INCREASING AS THE BOUNDARY LAYER
STABILIZES...AND THIS MIGHT RESULT IN A GRADUAL WEAKENING TREND AS
ACTIVITY CROSSES THE RED RIVER.

..DIAL.. 05/30/2012

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

ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

LAT...LON   35419503 34819441 33929480 33359631 33599784 34629860
            35529819 34849622 35419503

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 7:33 PM CDTSevere Thunderstorm WatchSPCChoctaw, Creek, Haskell, Latimer, LeFlore, McIntosh and 11 more5 hr
May 29, 8:21 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 32 more54 min
May 29, 9:10 PM CDTMesoscale DiscussionSPCAtoka, Canadian, Carter, Cleveland, Coal, Garvin and 10 more95 min
May 30, 12:43 AM CDTSevere Thunderstorm WatchSPCMcCurtain7 hr
May 30, 2:43 AM CDTMesoscale DiscussionSPCCotton, Tillman92 min
May 30, 3:38 PM CDTTornado WatchSPCBeaver, Harmon5 hr
May 30, 5:47 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Comanche, Custer, Dewey, Ellis and 10 more88 min
May 30, 6:13 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 37 more8 hr
May 29, 8:54 PM CDTMesoscale DiscussionSPCCollin, Dallas, Denton, Hood, Jack, Johnson and 6 more96 min
May 30, 5:07 AM CDTMesoscale DiscussionSPCAnderson, Camp, Cherokee, Collin, Dallas, Denton and 28 more83 min
May 30, 2:58 PM CDTMesoscale DiscussionSPCBriscoe, Childress, Collingsworth, Cottle, Dickens, Donley and 8 more62 min
May 30, 4:52 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Eastland and 17 more83 min
May 30, 5:11 PM CDTTornado WatchSPCBrown, Burnet, Callahan, Coke, Coleman, Comanche and 27 more6 hr

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.