Alert archive / Oklahoma / Mesoscale Discussions in 2016

Mesoscale Discussion 616

May 11, 20165 counties in Arkansas; 16 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 11, 2016, 11:46 PM CDT for 5 counties in Arkansas; 16 counties in Oklahoma. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: May 11, 2016, 11:46 PM CDT (04:46 UTC)
Expired: May 12, 2016, 1:45 AM CDT
In force: 119 min
Issued by: the Storm Prediction Center

All 21 counties

Crawford County, AR, Franklin County, AR, Logan County, AR, Scott County, AR, Sebastian County, AR, Atoka County, OK, Carter County, OK, Coal County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK

The radar

The Norman radar (KTLX), 139 km from the middle of the area, began a volume at 04:49 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, 4.8 hours before the alert went out and 146 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: 1887 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 1366 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.2

Open this sounding in Storm Lab

The text

As transmitted.

561 
ACUS11 KWNS 120447
SWOMCD
SPC MCD 120446 
ARZ000-OKZ000-120645-

MESOSCALE DISCUSSION 0616
NWS STORM PREDICTION CENTER NORMAN OK
1146 PM CDT WED MAY 11 2016

AREAS AFFECTED...SE OK AND NW AR

CONCERNING...SEVERE THUNDERSTORM WATCH 172...

VALID 120446Z - 120645Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 172
CONTINUES.

SUMMARY...A SEVERE THREAT IS EXPECTED TO CONTINUE MOVING INTO ERN OK
AND NW AR OVER THE NEXT 2 TO 3 HOURS. LARGE HAIL WILL BE POSSIBLE
WITH THE STRONGER UPDRAFTS BUT A FEW DAMAGING WIND GUSTS CAN NOT BE
RULED OUT.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SWWD
FROM SW MO INTO ERN AND SRN OK. THUNDERSTORMS HAVE DEVELOPED ALONG
THE BOUNDARY OVER THE LAST COUPLE OF HOURS IN RESPONSE TO INCREASING
LARGE-SCALE ASCENT ASSOCIATED WITH AN APPROACHING UPPER-LEVEL TROUGH
MOVING INTO THE SRN PLAINS. MODERATE INSTABILITY...STEEP LAPSE RATES
AND SUBSTANTIAL EFFECTIVE SHEAR SHOULD BE FAVORABLE FOR ROTATING
STORMS AND ISOLATED LARGE HAIL. ALTHOUGH A NEAR SFC INVERSION EXISTS
IN THE BOUNDARY LAYER....A FEW DAMAGING WIND GUSTS CAN NOT BE RULED
OUT WITH THE STRONGER DOWNDRAFTS.

..BROYLES/THOMPSON.. 05/12/2016

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

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

LAT...LON   34779755 34459772 34089752 34139650 34409445 35119358
            35769349 35949398 35789477 35079701 34779755

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 8:11 PM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Crawford, Franklin and 5 more	3 hr
May 11, 10:13 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more	7 hr
May 12, 2:48 AM CDT	Mesoscale Discussion	SPC	Cleburne, Conway, Craighead, Faulkner, Garland, Greene and 17 more	87 min
May 12, 9:10 AM CDT	Mesoscale Discussion	SPC	Craighead, Crittenden, Cross, Greene, Mississippi, Poinsett	95 min
May 12, 2:33 PM CDT	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Desha, Drew and 1 more	87 min
May 11, 10:13 PM CDT	Mesoscale Discussion	SPC	Beckham, Greer, Harmon, Jackson, Kiowa, Tillman	92 min
May 12, 2:12 AM CDT	Mesoscale Discussion	SPC	Carter, Comanche, Cotton, Jefferson, Stephens, Tillman	93 min

Nearby

Mesoscale Discussions in Oklahoma, 2016 Mesoscale Discussions in Arkansas, 2016 Every mesoscale discussion in 2016

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.