Alert archive / Alabama / Mesoscale Discussions in 2004

Mesoscale Discussion 2513

December 7, 200419 counties in Alabama

The Storm Prediction Center issued this mesoscale discussion at Dec 7, 2004, 4:56 AM CST for 19 counties in Alabama. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Dec 7, 2004, 4:56 AM CST (10:56 UTC)
Expired
Dec 7, 2004, 6:30 AM CST
In force
94 min
Issued by
the Storm Prediction Center

Counties Bibb County, AL, Blount County, AL, Cullman County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL

The radar

The Birmingham radar (KBMX), 73 km from the middle of the area, began a volume at 10:57 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

Birmingham, AL (KBMX), launched 00:00Z, 10.9 hours before the alert went out and 72 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, Birmingham, AL at 00:00Z on 2004-12-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 415 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, Birmingham, AL at 00:00Z on 2004-12-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.1939587897Sfc1 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
415 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
485 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
447 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

929 
ACUS11 KWNS 071057
SWOMCD
SPC MCD 071056 
ALZ000-MSZ000-071230-

MESOSCALE DISCUSSION 2513
NWS STORM PREDICTION CENTER NORMAN OK
0456 AM CST TUE DEC 07 2004

AREAS AFFECTED...CNTRL/NRN AL

CONCERNING...TORNADO WATCH 915...

VALID 071056Z - 071230Z

THE TORNADO/DAMAGING WIND THREATS CONTINUE ACROSS NRN/CNTRL AL.

LINE OF TSTMS CONTINUES TO CONTAIN EMBEDDED SUPERCELL STRUCTURES AS
IT ADVANCES ACROSS NRN/CNTRL AL.  A COUPLE OF CELLS HAVE ALSO
EXHIBITED LOW LEVEL ROTATION...PARTICULARLY VCNTY A WARM FRONT /MID
TO UPPER 60S DEW POINTS/ NW OF TUSCALOOSA.  THE BIRMINGHAM VWP SHOWS
STRONG LOW-MID LEVEL FLOW AND USING A STORM MOTION OF 230/45...0-1KM
SRH REMAINS AOA 225 M2/S2.  THUS...RISKS FOR TORNADOES WILL CONTINUE
ACROSS PARTS OF NRN/CNTRL AL...WITH THE HIGHEST PROBABILITIES IN A
CORRIDOR FROM TUSCALOOSA-JASPER- BIRMINGHAM.  

AIR MASS HAS DESTABILIZED FARTHER NORTH ACROSS NERN AL...BUT IT
APPEARS THE TORNADO THREAT MAY DECREASE AS THE TSTMS MOVE EWD TOWARD
HUNTSVILLE...GUNTERSVILLE...GADSDEN AND ANNISTON OWING TO SLIGHTLY
LOWER BOUNDARY LAYER DEW POINTS.  BUT...DAMAGING WINDS WILL CONTINUE
TO BE A THREAT.

..RACY.. 12/07/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BMX...HUN...JAN...

32438865 34978723 34968570 32418721

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 7, 1:25 AM CSTMesoscale DiscussionSPCBibb, Blount, Choctaw, Clarke, Cullman, Fayette and 14 more95 min
Dec 7, 3:25 AM CSTTornado WatchSPCBibb, Blount, Cullman, Fayette, Franklin, Greene and 17 more5 hr
Dec 7, 6:03 AM CSTMesoscale DiscussionSPCBaldwin, Clarke, Mobile, Monroe, Washington57 min
Dec 7, 6:58 AM CSTMesoscale DiscussionSPCBibb, Blount, Cullman, Hale, Jackson, Jefferson and 3 more62 min

Nearby

Mesoscale Discussions in Alabama, 2004Every mesoscale discussion in 2004

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.