Alert archive / Arkansas / Mesoscale Discussions in 2009
Mesoscale Discussion 646
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2009, 3:34 PM CDT for 6 states. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2009, 3:34 PM CDT (20:34 UTC)
- Expired
- Apr 30, 2009, 5:00 PM CDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
All 81 counties
Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clay County, AR, Cleveland County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Desha County, AR, Drew County, AR, Greene County, AR, Jackson County, AR, Lee County, AR, Lincoln County, AR, Mississippi County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, St. Francis County, AR, Union County, AR, Woodruff County, AR, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, McCracken County, KY, Claiborne Parish, LA, East Carroll Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Union Parish, LA, West Carroll Parish, LA, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Humphreys County, MS, Issaquena County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Washington County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN
The radar
The Memphis radar (KNQA), 103 km from the middle of the area, began a volume at 20:36 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
Little Rock, AR (KLZK), launched 12:00Z, 8.6 hours before the alert went out and 73 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.
- Mixed-layer CAPE
- 14 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 507 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- -57 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 1:55 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Johnson, Logan, Madison, Perry and 5 more | 2 hr |
| Apr 30, 5:10 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Craighead, Crittenden, Cross, Faulkner, Greene and 11 more | 5 hr |
Nearby
Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Mississippi, 2009Mesoscale Discussions in Tennessee, 2009Every 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.