Alert archive / Alabama / Mesoscale Discussions in 2012

Mesoscale Discussion 467

April 5, 201228 counties in Alabama; Holmes County, Florida; 11 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2012, 7:54 PM CDT for 28 counties in Alabama; Holmes County, Florida; 11 counties in Georgia. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Apr 5, 2012, 7:54 PM CDT (00:54 UTC)
Expired
Apr 5, 2012, 9:30 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 40 counties

Autauga County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Clay County, AL, Cleburne County, AL, Coffee County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Elmore County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Holmes County, FL, Chattahoochee County, GA, Clay County, GA, Early County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Troup County, GA

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 0.9 hours before the alert went out and 113 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 2012-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 242 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 2012-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 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
242 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1349 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

750 
ACUS11 KWNS 060055
SWOMCD
SPC MCD 060054
GAZ000-FLZ000-ALZ000-060230-

MESOSCALE DISCUSSION 0467
NWS STORM PREDICTION CENTER NORMAN OK
0754 PM CDT THU APR 05 2012

AREAS AFFECTED...ERN AL...FAR WRN GA...WRN FL PANHANDLE

CONCERNING...SEVERE THUNDERSTORM WATCH 149...

VALID 060054Z - 060230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 149
CONTINUES.

THE SEVERE THREAT SHOULD CONTINUE ACROSS WW 149 THIS EVENING WHERE
LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE. THE THREAT SHOULD
DEVELOP SEWD WITH TIME AND MAY AFFECT SE AL AND SW GA LATER THIS
EVENING.

A BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING IN ECNTRL
AL LOCATED JUST AHEAD OF A COLD FRONT. SFC DEWPOINTS AHEAD OF THE
FRONT ARE IN THE UPPER 50S F AND LOWER 60S F WITH MLCAPE ESTIMATED
IN THE 500 TO 1000 J/KG RANGE. IN ADDITION...MESOANALYSIS SHOWS A
WELL-DEFINED 55 TO 70 KT MID-LEVEL JET NOSING INTO THE REGION FROM
THE WEST. THIS IS CREATING A STRONGLY SHEARED ENVIRONMENT WITH THE
BIRMINGHAM 00Z SOUNDING SHOWING 60 KT OF 0-6 KM SHEAR. THIS
ENVIRONMENT SHOULD BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL. THE
WIND DAMAGE THREAT MAY INCREASE ESPECIALLY IF CURRENT RADAR TRENDS
PERSIST WHICH SHOW A LINE COULD BE DEVELOPING IN CNTRL AL. AS THE
STORMS APPROACH THE AL-GA STATE-LINE...SOME WEAKENING MAY OCCUR DUE
TO A SHARP DROP OFF IN INSTABILITY.

..BROYLES.. 04/06/2012

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

ATTN...WFO...FFC...TAE...BMX...MOB...

LAT...LON   33818515 34128559 34048606 33768640 33338663 32838672
            32458676 31298680 30858661 30688587 30898507 31208477
            32098468 33818515

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 7:44 AM CDTMesoscale DiscussionSPCBroward, Collier, Hendry, Miami-Dade, Monroe, Palm Beach91 min

Nearby

Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Florida, 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.