Alert archive / Mississippi / Mesoscale Discussions in 2009

Mesoscale Discussion 170

February 27, 200910 counties in Alabama; 9 counties in Arkansas; 24 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 27, 2009, 8:48 PM CST for 10 counties in Alabama; 9 counties in Arkansas; 24 counties in Mississippi. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Feb 27, 2009, 8:48 PM CST (02:48 UTC)
Expired
Feb 27, 2009, 10:45 PM CST
In force
117 min
Issued by
the Storm Prediction Center
All 43 counties

Colbert County, AL, Cullman County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Marion County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Arkansas County, AR, Cleveland County, AR, Desha County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Monroe County, AR, Phillips County, AR, Alcorn County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS

The radar

The Memphis radar (KNQA), 132 km from the middle of the area, began a volume at 02:51 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, 2.8 hours before the alert went out and 75 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 2009-02-28Temperature 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, Little Rock, AR at 00:00Z on 2009-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939587897117136Sfc1 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
1273 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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
Feb 27, 6:38 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 30 more97 min
Feb 27, 7:45 PM CSTTornado WatchSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 28 more7 hr
Feb 27, 10:47 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Chambers, Chilton and 23 more118 min
Feb 28, 2:15 AM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Chambers, Chilton and 25 more90 min
Feb 28, 2:52 AM CSTTornado WatchSPCAutauga, Barbour, Bibb, Bullock, Chambers, Chilton and 15 more9 hr
Feb 28, 5:40 AM CSTMesoscale DiscussionSPCAutauga, Bullock, Butler, Chilton, Choctaw, Clarke and 17 more2 hr
Feb 28, 9:49 AM CSTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Coffee, Conecuh, Covington and 8 more86 min
Feb 28, 10:39 AM CSTTornado WatchSPCCoffee, Covington, Dale, Geneva, Henry, Houston7 hr
Feb 28, 3:57 PM CSTMesoscale DiscussionSPCColbert, Lauderdale4 hr
Feb 28, 5:43 PM CSTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston8 hr
Feb 28, 11:47 AM CSTMesoscale DiscussionSPCClay, Craighead, Fulton, Greene, Lawrence, Mississippi and 3 more4 hr

Nearby

Mesoscale Discussions in Mississippi, 2009Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Arkansas, 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.