Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 1736
The Storm Prediction Center issued this mesoscale discussion at Aug 10, 2012, 2:55 PM CDT for 28 counties in Alabama; 4 counties in Georgia; 24 counties in Mississippi. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Aug 10, 2012, 2:55 PM CDT (19:55 UTC)
- Expired
- Aug 10, 2012, 4:30 PM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 56 counties
Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Chattooga County, GA, Dade County, GA, Floyd County, GA, Walker County, GA, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Itawamba County, MS, Kemper County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Tallahatchie County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS
The radar
The Columbus AFB radar (KGWX), 42 km from the middle of the area, began a volume at 19:55 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 12:00Z, 7.9 hours before the alert went out and 123 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.
- Mixed-layer CAPE
- 99 J/kg
- Mixed-layer CIN
- -153 J/kg
- Mixed-layer LCL
- 615 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 40 m²/s²
- 0-3 km storm-relative helicity
- 67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
219
ACUS11 KWNS 101956
SWOMCD
SPC MCD 101955
GAZ000-TNZ000-ALZ000-MSZ000-102130-
MESOSCALE DISCUSSION 1736
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT FRI AUG 10 2012
AREAS AFFECTED...FAR NW GA...NRN AL...PORTIONS OF CNTRL MS
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 101955Z - 102130Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED/LOCALLY DAMAGING WIND THREAT WILL ACCOMPANY
STORMS THIS AFTERNOON. SEVERE POTENTIAL SHOULD REMAIN SUFFICIENTLY
LIMITED AND A WW IS NOT EXPECTED AT THIS TIME. THUNDERSTORMS WILL
DEVELOP E/SEWD AHEAD OF A COLD FRONT FROM CNTRL MS INTO NW GA
THROUGH THE EVENING HOURS.
DISCUSSION...THUNDERSTORM COVERAGE WILL INCREASE THROUGH EARLY
EVENING AHEAD OF AN APPROACHING COLD FRONT. THIS COLD FRONT WAS
LOCATED FROM MIDDLE TN INTO NW MS AND SRN AR AS OF 1930Z. WEAK
FORCING COMBINED WITH LIGHT DEEP LAYER FLOW SHOULD LIMIT STORM
ORGANIZATION BUT 25-30 KT BULK SHEAR WILL RESULT IN STORM CLUSTERS.
LOCALIZED DAMAGING WIND THREAT WILL BE ENHANCED BY PW VALUES
APPROACHING 2 INCHES...POTENTIALLY ENHANCING DOWNDRAFTS RESULTING IN
STRONG DOWNBURST WINDS. BECAUSE MIDLEVEL LAPSE RATES ARE NOT VERY
STEEP /LESS THAN 6.5 C PER KM/ DOWNBURST POTENTIAL SHOULD REMAIN
ISOLATED. STORMS MAY BE A LITTLE SLOWER TO DEVELOP INTO NRN AL/NW GA
WHERE TEMPERATURES WERE SLIGHTLY COOLER THIS AFTERNOON AND
INSTABILITY NOT AS STRONG. HOWEVER...AS THE COLD FRONT MOVE SLOWLY
SEWD...STORMS SHOULD DEVELOP EWD WITH TIME...ALONG WITH ISOLATED
DAMAGING WIND THREAT.
..LEITMAN/CORFIDI.. 08/10/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MRX...FFC...BMX...HUN...MEG...JAN...
LAT...LON 34718503 33958532 33208636 32698770 32478879 32648983
32949022 33379054 33849044 34069003 34218942 34958656
35018538 34718503Nearby
Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Georgia, 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; radar from the NEXRAD Level II archive.