Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 973

May 29, 201216 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 29, 2012, 9:10 PM CDT for 16 counties in Oklahoma. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: May 29, 2012, 9:10 PM CDT (02:10 UTC)
Expired: May 29, 2012, 10:45 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

Counties Atoka County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Johnston County, OK, McClain County, OK, Murray County, OK, Oklahoma County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 50 km from the middle of the area, began a volume at 02:13 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 51 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

153 
ACUS11 KWNS 300211
SWOMCD
SPC MCD 300210
OKZ000-300345-

MESOSCALE DISCUSSION 0973
NWS STORM PREDICTION CENTER NORMAN OK
0910 PM CDT TUE MAY 29 2012

AREAS AFFECTED...CNTRL/S-CNTRL OK

CONCERNING...SEVERE THUNDERSTORM WATCH 317...319...

VALID 300210Z - 300345Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
317...319...CONTINUES.

SUMMARY...WIND THREAT EXPECTED TO INCREASE IN ADDITION TO THE THREAT
OF VERY LARGE HAIL ACROSS CNTRL/S-CNTRL OK.

DISCUSSION...COMPLEX INTERACTION BETWEEN SUPERCELLS APPEARS TO BE
EVOLVING INTO A CONVECTIVE LINE/MCS ACROSS CNTRL OK. ONE SUPERCELL
ACCELERATED ACROSS KINGFISHER AND CANADIAN COUNTIES WHILE
LEFT-MOVING AND RIGHT-MOVING SUPERCELLS COLLIDED OVER OKLAHOMA
COUNTY. CURRENT THINKING IS THAT THE COLLISION WILL RESULT IN
UPSCALE GROWTH INTO A MESO-LOW WHILE THE ACCELERATING SUPERCELL
FORMS THE APEX OF A BOWING SEGMENT. THIS LINE SHOULD THEN BEGIN TO
ACCELERATE SWD/SEWD ACROSS CNTRL OK AND INTO S-CNTRL OK.
THEREFORE...CONVECTIVE WIND THREAT SHOULD BEGIN TO INCREASE WITH A
CONTINUING THREAT FOR VERY LARGE HAIL.

..MOSIER/HART.. 05/30/2012

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

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

LAT...LON   35369842 35929814 35729754 35439626 35309556 34869532
            34279569 34119619 34149698 34339767 35369842

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 29, 7:33 PM CDT	Severe Thunderstorm Watch	SPC	Choctaw, Creek, Haskell, Latimer, LeFlore, McIntosh and 11 more	5 hr
May 29, 8:21 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 32 more	54 min
May 29, 11:28 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Carter, Choctaw, Cleveland, Coal and 17 more	62 min
May 30, 12:43 AM CDT	Severe Thunderstorm Watch	SPC	McCurtain	7 hr
May 30, 2:43 AM CDT	Mesoscale Discussion	SPC	Cotton, Tillman	92 min
May 30, 3:38 PM CDT	Tornado Watch	SPC	Beaver, Harmon	5 hr
May 30, 5:47 PM CDT	Mesoscale Discussion	SPC	Beckham, Blaine, Comanche, Custer, Dewey, Ellis and 10 more	88 min
May 30, 6:13 PM CDT	Severe Thunderstorm Watch	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 37 more	8 hr

Nearby

Mesoscale Discussions in Oklahoma, 2012 Every 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.