Alert archive / Arkansas / Mesoscale Discussions in 2017

Mesoscale Discussion 581

April 28, 20176 states

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2017, 6:28 PM CDT for 6 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 28, 2017, 6:28 PM CDT (23:28 UTC)
Expired
Apr 28, 2017, 9:00 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 96 counties

Baxter County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion 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, Washington County, AR, Yell County, AR, Alexander County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, Wabash County, IL, White County, IL, Williamson County, IL, Posey County, IN, Ballard County, KY, Caldwell County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dent County, MO, Douglas County, MO, Dunklin County, MO, Howell County, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Ozark County, MO, Perry County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Wright County, MO, LeFlore County, OK

The radar

The St Louis radar (KLSX), 196 km from the middle of the area, began a volume at 23:30 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.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 11.5 hours before the alert went out and 250 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-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2017-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2017-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -51 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
960 m above ground
0-6 km bulk shear
76 kt
0-1 km storm-relative helicity
-51 m²/s²
0-3 km storm-relative helicity
278 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 1:10 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Coles and 35 more2 hr
Apr 28, 4:59 PM CDTMesoscale DiscussionSPCMassac91 min
Apr 28, 5:48 PM CDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clark, Clay, Daviess and 35 more117 min
Apr 28, 2:33 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 44 more87 min

Nearby

Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Missouri, 2017Mesoscale Discussions in Illinois, 2017Every mesoscale discussion in 2017

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.