Alert archive / Arkansas / Mesoscale Discussions in 2009

Mesoscale Discussion 618

April 28, 200928 counties in Arkansas; 9 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2009, 5:43 PM CDT for 28 counties in Arkansas; 9 counties in Missouri. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Apr 28, 2009, 5:43 PM CDT (22:43 UTC)
Expired: Apr 28, 2009, 6:45 PM CDT
In force: 62 min
Issued by: the Storm Prediction Center

All 37 counties

Baxter County, AR, Boone County, AR, Carroll County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Independence County, AR, Izard County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pope County, AR, Randolph County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Yell County, AR, Butler County, MO, Carter County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Ripley County, MO, Shannon County, MO, Taney County, MO, Wayne County, MO

The radar

The Little Rock radar (KLZK), 108 km from the middle of the area, began a volume at 22:47 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

Little Rock, AR (KLZK), launched 12:00Z, 10.7 hours before the alert went out and 262 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: 830 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 445 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 76 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

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 27, 7:08 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 22 more	67 min
Apr 27, 8:54 PM CDT	Mesoscale Discussion	SPC	Baxter, Clark, Cleburne, Conway, Faulkner, Fulton and 22 more	66 min

Nearby

Mesoscale Discussions in Arkansas, 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.