Alert archive / Mississippi / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 475
The Storm Prediction Center issued this severe thunderstorm watch at Jul 6, 2012, 5:08 PM CDT for 12 counties in Alabama; 30 counties in Mississippi. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 6, 2012, 5:08 PM CDT (22:08 UTC)
- Expired
- Jul 6, 2012, 9:35 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 42 counties
Bibb County, AL, Dallas County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Lamar County, AL, Marengo County, AL, Marion County, AL, Perry County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 121 km from the middle of the area, began a volume at 22:08 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 5:23 PM CDT | Severe Thunderstorm Warning | JAN | Lowndes | 52 min |
| Jul 6, 5:40 PM CDT | Severe Thunderstorm Warning | JAN | Choctaw, Clay, Oktibbeha, Webster | 65 min |
| Jul 6, 6:05 PM CDT | Severe Thunderstorm Warning | JAN | Lowndes, Oktibbeha | 40 min |
| Jul 6, 6:26 PM CDT | Severe Thunderstorm Warning | JAN | Noxubee, Winston | 49 min |
| Jul 6, 6:43 PM CDT | Severe Thunderstorm Warning | JAN | Oktibbeha | 31 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Jackson, MS (KJAN), launched 12:00Z, 10.1 hours before the alert went out and 119 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
- 747 J/kg
- Mixed-layer CIN
- -180 J/kg
- Mixed-layer LCL
- 1412 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 29 m²/s²
- 0-3 km storm-relative helicity
- 62 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
411
WWUS20 KWNS 062210
SEL5
SPC WW 062210
ALZ000-MSZ000-070300-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 475
NWS STORM PREDICTION CENTER NORMAN OK
510 PM CDT FRI JUL 6 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
WESTERN ALABAMA
CENTRAL MISSISSIPPI
EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 510 PM UNTIL
1000 PM CDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 105
STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTHEAST OF
GREENWOOD MISSISSIPPI TO 60 MILES EAST OF JACKSON MISSISSIPPI.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 474...
DISCUSSION...CLUSTERS OF STRONG TO SVR PULSE TSTMS IN NE MS APPEARS
TO HAVE DEVELOPED A SUFFICIENTLY STRONG COLD POOL THAT MAY SUPPORT
CONTINUED SW STORM PROPAGATION GIVEN 20-25 KT 700 MB FLOW /PER VWP
DATA/ AND CORRIDOR OF RICH LOW LVL MOISTURE ACROSS REGION /PER SFC
OBS AND STLT-GPS DERIVED PW/. OTHER STORMS MAY FORM IN ZONE OF
UPLIFT AND ENHANCED LOW LVL INSTABILITY ALONG/AHEAD OF OUTFLOW
BOUNDARY OVER NW AND W CNTRL AL. SETUP MAY YIELD NARROW CORRIDORS
OF LOCALLY DMGG WIND AND POSSIBLY MARGINALLY SVR HAIL THROUGH LATE
EVE.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 05020.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 2:36 PM CDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lauderdale | 84 min |
| Jul 6, 2:58 PM CDT | Severe Thunderstorm Watch | SPC | Colbert, Franklin, Lamar, Lauderdale, Lawrence, Marion | 5 hr |
| Jul 6, 6:15 PM CDT | Mesoscale Discussion | SPC | Greene, Pickens, Sumter | 2 hr |
| Jul 6, 12:42 PM CDT | Mesoscale Discussion | SPC | Clay, Greene, Mississippi | 93 min |
Nearby
Severe Thunderstorm Watches in Mississippi, 2012Severe Thunderstorm Watches in Alabama, 2012Every severe thunderstorm watch 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.