Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 368

April 18, 201519 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2015, 8:02 PM CDT for 19 counties in Oklahoma. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Apr 18, 2015, 8:02 PM CDT (01:02 UTC)
Expired: Apr 18, 2015, 9:30 PM CDT
In force: 88 min
Issued by: the Storm Prediction Center

Counties Carter County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Garvin County, OK, Hughes County, OK, Johnston County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Murray County, OK, Okfuskee County, OK, Oklahoma County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 23 km from the middle of the area, began a volume at 01:05 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, 1.0 hours before the alert went out and 28 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: 927 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1566 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 18, 7:46 PM CDT	Mesoscale Discussion	SPC	Beckham, Blaine, Comanche, Custer, Dewey, Ellis and 10 more	89 min
Apr 19, 12:43 PM CDT	Mesoscale Discussion	SPC	Adair, Alfalfa, Atoka, Blaine, Bryan, Caddo and 51 more	2 hr
Apr 19, 1:42 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Choctaw, Cleveland, Craig, Creek and 32 more	6 hr
Apr 19, 2:31 PM CDT	Severe Thunderstorm Watch	SPC	McCurtain	7 hr

Nearby

Mesoscale Discussions in Oklahoma, 2015 Every mesoscale discussion in 2015

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.