Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 913

May 23, 20116 counties in Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 23, 2011, 7:50 PM CDT for 6 counties in Oklahoma; 5 counties in Texas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: May 23, 2011, 7:50 PM CDT (00:50 UTC)
Expired: May 23, 2011, 8:45 PM CDT
In force: 55 min
Issued by: the Storm Prediction Center

Counties Comanche County, OK, Cotton County, OK, Jackson County, OK, Jefferson County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 28 km from the middle of the area, began a volume at 00:50 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, 0.8 hours before the alert went out and 163 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: 2770 J/kg
Mixed-layer CIN: -141 J/kg
Mixed-layer LCL: 888 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 319 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 12.4

Open this sounding in Storm Lab

The text

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

594 
ACUS11 KWNS 240051
SWOMCD
SPC MCD 240050
TXZ000-OKZ000-240145-

MESOSCALE DISCUSSION 0913
NWS STORM PREDICTION CENTER NORMAN OK
0750 PM CDT MON MAY 23 2011

AREAS AFFECTED...SWRN OK THROUGH NWRN TX

CONCERNING...TORNADO WATCH 345...

VALID 240050Z - 240145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 345 CONTINUES.

SUPERCELLS ARE IN THE PROCESS OF RAPIDLY DIMINISHING FROM SWRN OK
INTO NWRN TX. ADDITIONAL THUNDERSTORM DEVELOPMENT APPEARS UNLIKELY
IN THIS AREA THE REMAINDER OF THE EVENING...AND LAST TWO ROWS OF
COUNTIES IN SWRN OK AND THE REMAINDER OF NWRN TX CAN PROBABLY BE
REMOVED FROM WW ONCE STORMS DISSIPATE.

THE DISCRETE SUPERCELLS THAT DEVELOPED EARLIER IN THE DAY ALONG THE
DRYLINE ACROSS WERE PRIMARILY DIURNALLY DRIVEN. RAPIDLY INCREASING
CONVECTIVE INHIBITION RESULTING FROM A STABILIZING BOUNDARY LAYER AS
WELL AS SHORTWAVE RIDGING ALOFT SUGGEST THAT ADDITIONAL DEVELOPMENT
IS UNLIKELY THIS EVENING OVER SWRN OK INTO NWRN TX.

STORMS WILL LIKELY CONTINUE DEVELOPING HOWEVER ACROSS NRN OK WHERE A
STRONG SLY LLJ WILL MAINTAIN CONVERGENCE AND ISENTROPIC LIFT ALONG
AN OUTFLOW BOUNDARY. SOME OF THIS ACTIVITY MIGHT EVENTUALLY BECOME
FORWARD PROPAGATING AND ADVANCE SEWD INTO CNTRL OK.

..DIAL.. 05/24/2011

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

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

LAT...LON   34859939 34729788 34159763 33639803 33479902 33989968
            34859939

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 23, 9:22 PM CDT	Mesoscale Discussion	SPC	Adair, Blaine, Canadian, Cherokee, Creek, Haskell and 15 more	23 min
May 23, 9:42 PM CDT	Severe Thunderstorm Watch	SPC	Blaine, Caddo, Canadian, Cleveland, Creek, Grady and 18 more	6 hr
May 24, 2:08 AM CDT	Mesoscale Discussion	SPC	Cherokee, Creek, Haskell, LeFlore, McIntosh, Muskogee and 5 more	97 min
May 24, 12:18 PM CDT	Mesoscale Discussion	SPC	Blaine, Caddo, Canadian, Carter, Cleveland, Comanche and 21 more	87 min
May 24, 12:47 PM CDT	Tornado Watch PDS	SPC	Alfalfa, Atoka, Blaine, Bryan, Caddo, Canadian and 51 more	11 hr
May 24, 2:35 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Grant, Kay, Woods	85 min
May 24, 4:48 PM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Carter, Cleveland, Cotton, Creek and 21 more	87 min
May 24, 6:43 PM CDT	Mesoscale Discussion	SPC	Bryan, Carter, Cleveland, Coal, Creek, Garvin and 17 more	62 min
May 24, 2:15 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Comanche, Concho and 28 more	90 min

Nearby

Mesoscale Discussions in Oklahoma, 2011 Mesoscale Discussions in Texas, 2011 Every mesoscale discussion in 2011

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.