Alert archive / Alabama / Tornado Watches in 2008

Tornado Watch 864

August 25, 200811 counties in Alabama; 6 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Aug 25, 2008, 11:56 AM CDT for 11 counties in Alabama; 6 counties in Tennessee. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Aug 25, 2008, 11:56 AM CDT (16:56 UTC)
Expired
Aug 25, 2008, 3:01 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center

Counties Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Franklin County, TN, Giles County, TN, Lawrence County, TN, Lincoln County, TN, Moore County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 41 km from the middle of the area, began a volume at 17:00 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.

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 4.9 hours before the alert went out and 160 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, Nashville Metro, TN at 12:00Z on 2008-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 620 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, Nashville Metro, TN at 12:00Z on 2008-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939Sfc1 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
620 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
639 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 24, 7:03 PM CDTMesoscale DiscussionSPCBlount, Calhoun, Clay, Coosa, Fayette, Jefferson and 6 more57 min
Aug 24, 11:38 PM CDTMesoscale DiscussionSPCBaldwin, Conecuh, Escambia, Monroe97 min
Aug 25, 1:10 AM CDTTornado WatchSPCBaldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 14 more6 hr
Aug 25, 4:34 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 25 more86 min
Aug 25, 7:28 AM CDTTornado WatchSPCAutauga, Barbour, Bibb, Blount, Bullock, Butler and 41 more13 hr
Aug 25, 10:26 AM CDTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Butler and 53 more64 min
Aug 25, 2:07 PM CDTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Butler and 31 more53 min
Aug 25, 6:14 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Butler, Chambers, Coffee, Coosa and 14 more91 min

Nearby

Tornado Watches in Alabama, 2008Tornado Watches in Tennessee, 2008Every tornado watch in 2008

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.