Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 986

May 30, 201216 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 30, 2012, 5:47 PM CDT for 16 counties in Oklahoma. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: May 30, 2012, 5:47 PM CDT (22:47 UTC)
Expired: May 30, 2012, 7:15 PM CDT
In force: 88 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Beckham County, OK, Blaine County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harper County, OK, Jackson County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK

The radar

The Altus AFB radar (KFDR), 117 km from the middle of the area, began a volume at 22:46 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 325May 30, 6:15 PM CDT

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 10.8 hours before the alert went out and 157 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: 52 J/kg
Mixed-layer CIN: -388 J/kg
Mixed-layer LCL: 1888 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 132 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

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

139 
ACUS11 KWNS 302247
SWOMCD
SPC MCD 302247 
OKZ000-TXZ000-310015-

MESOSCALE DISCUSSION 0986
NWS STORM PREDICTION CENTER NORMAN OK
0547 PM CDT WED MAY 30 2012

AREAS AFFECTED...WRN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 302247Z - 310015Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A FEW SEVERE STORMS MAY OCCUR OVER WRN OK...WITH MAINLY AN
HAIL AND WIND THREAT. A NARROW N/S WATCH MAY BE NEEDED SOON.

DISCUSSION...STORMS HAVE DEVELOPED OVER WRN/SWRN OK...E OF THE TX
ACTIVITY WHERE CAPPING HAS BEEN LOCALLY BREACHED. THESE STORMS ARE
RELATIVELY WEAK AT THIS TIME...BUT STEEP LAPSE RATE PROFILES AND
NWLY DEEP LAYER SHEAR AROUND 40 KT WILL FAVOR SOME FURTHER
ORGANIZATION. 

BOUNDARY LAYER TEMPERATURE/DEWPOINT SPREADS ARE CURRENTLY AROUND 25
F...DUE TO MARGINAL LOW LEVEL MOISTURE WITH DEWPOINTS ONLY IN THE
UPPER 50S TO LOWER 60S F. HOWEVER...CONDITIONS MAY CHANGE THIS
EVENING WITH A PERSISTENT SLY LOW LEVEL JET AND SOME HIGHER THETA-E
OVER NWRN TX.

..JEWELL/CORFIDI.. 05/30/2012

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

ATTN...WFO...OUN...AMA...

LAT...LON   35009839 34549835 34209881 34619973 35079987 36270001
            36979999 36999846 35009839

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, 9:10 PM CDT	Mesoscale Discussion	SPC	Atoka, Canadian, Carter, Cleveland, Coal, Garvin and 10 more	95 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, 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.