Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 1922

September 7, 20127 states

The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2012, 8:24 PM CDT for 7 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Sep 7, 2012, 8:24 PM CDT (01:24 UTC)
Expired
Sep 7, 2012, 10:00 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 103 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Garland County, AR, Greene County, AR, Independence County, AR, Jackson County, AR, Lawrence County, AR, Lee County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Perry County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Posey County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian 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, McLean County, KY, Muhlenberg County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 76 km from the middle of the area, began a volume at 01:24 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 00:00Z, 1.4 hours before the alert went out and 132 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, Little Rock, AR at 00:00Z on 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2285 joules per kilogram.LCLLFCEL10008507005003002001001 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, Little Rock, AR at 00:00Z on 2012-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 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
2285 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1708 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.2
Supercell composite
5.2

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.

IssuedProductOfficeCountiesLasted
Sep 7, 8:10 PM CDTSevere Thunderstorm WatchSPCLee, Phillips6 hr
Sep 7, 7:39 PM CDTMesoscale DiscussionSPCBond, Christian, Clark, Clay, Clinton, Coles and 17 more66 min
Sep 7, 11:36 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Boone and 59 more84 min
Sep 7, 11:57 PM CDTMesoscale DiscussionSPCAnderson, Bath, Bourbon, Boyd, Bracken, Breathitt and 39 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Kentucky, 2012Every mesoscale discussion in 2012

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.