Alert archive / Oklahoma / Mesoscale Discussions in 2009

Mesoscale Discussion 844

May 15, 20097 counties in Missouri; 13 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 15, 2009, 10:55 PM CDT for 7 counties in Missouri; 13 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 15, 2009, 10:55 PM CDT (03:55 UTC)
Expired: May 16, 2009, 1:00 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Barry County, MO, Christian County, MO, Greene County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Webster County, MO, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Delaware County, OK, Lincoln County, OK, Mayes County, OK, McClain County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Pottawatomie County, OK, Tillman County, OK, Wagoner County, OK

The radar

The Norman radar (KTLX), 12 km from the middle of the area, began a volume at 03:58 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, 3.9 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: 2577 J/kg
Mixed-layer CIN: -126 J/kg
Mixed-layer LCL: 1117 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 202 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.1

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
May 15, 8:14 PM CDT	Mesoscale Discussion	SPC	Saint Louis, City of Saint Louis	2 hr
May 15, 10:39 PM CDT	Mesoscale Discussion	SPC	Crawford, Dade, Dent, Iron, Laclede, Madison and 6 more	2 hr
May 15, 7:11 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 40 more	64 min
May 15, 7:48 PM CDT	Severe Thunderstorm Watch	SPC	Caddo, Canadian, Cleveland, Comanche, Cotton, Craig and 29 more	5 hr

Nearby

Mesoscale Discussions in Oklahoma, 2009 Mesoscale Discussions in Missouri, 2009 Every mesoscale discussion in 2009

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.