Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 1880
The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2012, 3:42 PM CDT for 19 counties in Alabama; 5 counties in Mississippi. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- Sep 4, 2012, 3:42 PM CDT (20:42 UTC)
- Expired
- Sep 4, 2012, 4:45 PM CDT
- In force
- 63 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 24 counties
Autauga County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Crenshaw County, AL, Dallas County, AL, Greene County, AL, Hale County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL, Clarke County, MS, George County, MS, Greene County, MS, Lauderdale County, MS, Wayne County, MS
The radar
The Mobile radar (KMOB), 137 km from the middle of the area, began a volume at 20:41 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, 8.7 hours before the alert went out and 174 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
- 1659 J/kg
- Mixed-layer CIN
- -23 J/kg
- Mixed-layer LCL
- 531 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
786
ACUS11 KWNS 042043
SWOMCD
SPC MCD 042042
ALZ000-FLZ000-MSZ000-042145-
MESOSCALE DISCUSSION 1880
NWS STORM PREDICTION CENTER NORMAN OK
0342 PM CDT TUE SEP 04 2012
AREAS AFFECTED...E CNTRL/SERN MS AND CNTRL/SWRN AL
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 042042Z - 042145Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...A SMALL CLUSTER OF STRONG TO SEVERE STORMS CAPABLE OF DMGG
WINDS AND HEAVY RAINFALL WILL DRIFT SWD WITH TIME. THE AREA WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW.
DISCUSSION...CLEARING IN THE WAKE OF EARLIER CONVECTIVE DEBRIS
APPEARS TO HAVE ALLOWED SUFFICIENT SURFACE HEATING FOR MINIMAL
CONVECTIVE INHIBITION TO BE ERODED. STRONGER THUNDERSTORMS NOW
APPEAR TO BE DEVELOPING ALONG A CONFLUENT AXIS EXTENDING THROUGH
CNTRL AL. AS ADDITIONAL STORMS BEGIN TO FORM...QUICKLY COLLAPSING
CORES AMIDST A DEEPLY SATURATED AIR MASS /PRECIPITATION LOADING/
WILL GENERATE NEW OUTFLOW BOUNDARIES...POSSIBLY SUPPORTING AN
EVENTUAL MCS. HOWEVER...GENERALLY DISORGANIZED WIND FIELDS WITH
HEIGHT AND WEAKER LOW-LEVEL FLOW COMPARED TO YESTERDAY MAY LIMIT A
MORE WIDESPREAD WIND EVENT...THOUGH A HEAVY RAINFALL THREAT WILL
LIKELY CONTINUE.
..HURLBUT/CORFIDI.. 09/04/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...TAE...BMX...MOB...JAN...LIX...
LAT...LON 31608584 31258722 30538788 30438832 30778884 31508893
32078885 33038838 33088752 32748636 32198581 31608584SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 3, 9:28 PM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Butler, Chilton, Choctaw, Clarke and 17 more | 62 min |
Nearby
Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Mississippi, 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.