Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 425

April 10, 200919 counties in Alabama; 12 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2009, 4:25 AM CDT for 19 counties in Alabama; 12 counties in Georgia. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 10, 2009, 4:25 AM CDT (09:25 UTC)
Expired
Apr 10, 2009, 6:00 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 31 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Jackson County, AL, Jefferson County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Gordon County, GA, Haralson County, GA, Murray County, GA, Paulding County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA

The radar

The Northeast Alabama radar (KHTX), 99 km from the middle of the area, began a volume at 09:28 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 9.4 hours before the alert went out and 188 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, Peachtre/Fal Fld, GA at 00:00Z on 2009-04-10Temperature 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, Peachtre/Fal Fld, GA at 00:00Z on 2009-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2758 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Apr 10, 1:24 AM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lauderdale, Marion and 1 more96 min
Apr 10, 1:43 AM CDTTornado WatchSPCBlount, Colbert, Cullman, Fayette, Franklin, Greene and 12 more5 hr
Apr 10, 8:22 AM CDTMesoscale DiscussionSPCLauderdale83 min
Apr 10, 11:14 AM CDTMesoscale DiscussionSPCColbert, Franklin, Jackson, Lauderdale, Lawrence, Limestone and 4 more76 min
Apr 10, 11:23 AM CDTTornado Watch PDSSPCBibb, Blount, Calhoun, Cherokee, Cleburne, Colbert and 25 more8 hr
Apr 10, 12:58 PM CDTMesoscale DiscussionSPCColbert, Cullman, Fayette, Franklin, Jackson, Lamar and 8 more92 min
Apr 10, 2:29 PM CDTMesoscale DiscussionSPCCleburne91 min
Apr 10, 2:39 PM CDTTornado Watch PDSSPCAutauga, Barbour, Bullock, Calhoun, Chambers, Cherokee and 19 more8 hr
Apr 10, 3:43 PM CDTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Cleburne, DeKalb, Etowah and 4 more92 min
Apr 10, 6:34 PM CDTMesoscale DiscussionSPCAutauga, Calhoun, Chambers, Chilton, Clay, Cleburne and 9 more56 min
Apr 10, 7:04 AM CDTMesoscale DiscussionSPCBanks, Bartow, Chattooga, Cherokee, Cobb, Dawson and 23 more86 min
Apr 10, 5:11 PM CDTMesoscale DiscussionSPCBaldwin, Bibb, Butts, Clarke, Columbia, Crawford and 32 more64 min
Apr 10, 5:31 PM CDTTornado WatchSPCBaldwin, Bibb, Bleckley, Butts, Chattahoochee, Columbia and 53 more7 hr

Nearby

Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Georgia, 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.