Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 732

May 11, 201125 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 12:33 PM CDT for 25 counties in Oklahoma. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: May 11, 2011, 12:33 PM CDT (17:33 UTC)
Expired: May 11, 2011, 2:00 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center

All 25 counties

Atoka County, OK, Coal County, OK, Creek County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, Lincoln County, OK, Mayes County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Norman radar (KTLX), 96 km from the middle of the area, began a volume at 17:34 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.

Severe Thunderstorm Watch 280May 11, 1:20 PM CDT

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 5.6 hours before the alert went out and 108 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: 1845 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 652 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 117 m²/s²
0-3 km storm-relative helicity: 249 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

327 
ACUS11 KWNS 111733
SWOMCD
SPC MCD 111733 
OKZ000-111900-

MESOSCALE DISCUSSION 0732
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CDT WED MAY 11 2011

AREAS AFFECTED...ERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 111733Z - 111900Z

STORMS MAY UNDERGO INTENSIFICATION AS THEY DEVELOP EWD THROUGH THE
REMAINDER OF CNTRL INTO ERN OK THIS AFTERNOON. THE INITIAL PRIMARY
THREATS WILL BE ISOLATED LARGE HAIL AND DAMAGING WIND. AREA WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

PRE-FRONTAL BAND OF STORMS DEVELOPING ALONG WARM CONVEYOR BELT AND
IN ASSOCIATION WITH LEAD IMPULSE EJECTING NNEWD THROUGH SRN/CNTRL
PLAINS WILL LIKELY PERSIST THROUGH THE AFTERNOON. STEEP LAPSE RATES
HAVE ADVECTED ABOVE RICHER LOW LEVEL MOISTURE WITH MODERATE
INSTABILITY ACROSS ERN OK. HOWEVER...WIDESPREAD STRATUS HAS LIMITED
DIABATIC WARMING AND WILL CONTINUE TO SLOW BOUNDARY LAYER
DESTABILIZATION. ACTIVITY IS SHIFTING EAST OF THE STRONGER WINDS
ALOFT AND EFFECTIVE SHEAR ASSOCIATED WITH THE PRIMARY UPPER TROUGH
FURTHER WEST. THIS SUGGESTS STORM MODE SHOULD BE MAINLY
MULTICELLULAR INTO MUCH OF THE AFTERNOON. SOME INCREASE IN VERTICAL
SHEAR MAY OCCUR LATER IN THE AFTERNOON OR EVENING AS HEIGHTS FALL IN
RESPONSE TO VORT MAX EJECTING NEWD THROUGH THE HIGH PLAINS. LIMITED
BOUNDARY LAYER RECOVERY AND MODEST VERTICAL SHEAR COULD SERVE AS
OVERALL LIMITING FACTORS FOR A MORE ROBUST SEVERE EVENT.
NEVERTHELESS A FEW STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED
DAMAGING WIND AND LARGE HAIL.

..DIAL.. 05/11/2011

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

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

LAT...LON   34199693 36439724 36929608 36259499 34289517 34199693

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 2:28 AM CDT	Mesoscale Discussion	SPC	Texas	92 min
May 11, 7:30 AM CDT	Mesoscale Discussion	SPC	Beaver, Beckham, Ellis, Harmon, Harper, Roger Mills	60 min
May 11, 1:16 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Atoka, Bryan, Caddo, Canadian, Carter and 53 more	8 hr
May 11, 1:51 PM CDT	Mesoscale Discussion	SPC	Beaver, Harper	84 min
May 11, 2:51 PM CDT	Mesoscale Discussion	SPC	McCurtain	84 min
May 11, 3:46 PM CDT	Severe Thunderstorm Watch	SPC	McCurtain	8 hr
May 11, 6:02 PM CDT	Mesoscale Discussion	SPC	Ellis, Harper, Woods, Woodward	88 min
May 11, 6:35 PM CDT	Mesoscale Discussion	SPC	Adair, Cherokee, Craig, Delaware, LeFlore, Mayes and 3 more	55 min

Nearby

Mesoscale Discussions in Oklahoma, 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.