Alert archive / Mississippi / Tornado Watches in 2012
Tornado Watch 99
The Storm Prediction Center issued this tornado watch at Mar 22, 2012, 7:15 AM CDT for 4 counties in Mississippi. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 22, 2012, 7:15 AM CDT (12:15 UTC)
- Expired
- Mar 22, 2012, 12:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
Counties George County, MS, Harrison County, MS, Jackson County, MS, Stone County, MS
The radar
The Mobile radar (KMOB), 59 km from the middle of the area, began a volume at 12:15 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 22, 8:10 AM CDT | Flash Flood Warning | LIX | Jackson | 3 hr |
| Mar 22, 9:41 AM CDT | Flash Flood Warning | MOB | George, Greene, Perry, Stone, Wayne | 6 hr |
| Mar 22, 9:44 AM CDT | Tornado Warning | LIX | Jackson | 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
Slidell Radar S, LA (KSIL), launched 12:00Z, 0.3 hours before the alert went out and 89 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
- 2 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 438 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 148 m²/s²
- 0-3 km storm-relative helicity
- 377 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.3
The text
As transmitted, in the capitals the NWS used until 2016.
678
WWUS20 KWNS 221217
SEL9
SPC WW 221217
MSZ000-CWZ000-221700-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 99
NWS STORM PREDICTION CENTER NORMAN OK
715 AM CDT THU MAR 22 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
FAR SOUTHEASTERN MISSISSIPPI
COASTAL WATERS
EFFECTIVE THIS THURSDAY MORNING FROM 715 AM UNTIL NOON CDT.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF MOBILE
ALABAMA TO 40 MILES SOUTH SOUTHEAST OF GULFPORT MISSISSIPPI. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.
DISCUSSION...N-S BAND OF TSTMS /WITH EMBEDDED SUPERCELL STRUCTURES/
IS EXPECTED TO PERSIST THIS MORNING AS REGION IS GLANCED BY A
MIDLEVEL IMPULSE LIFTING NEWD THROUGH THE SABINE RIVER VALLEY.
AMBIENT INFLOW AIR MASS REMAINS MOIST AND MODERATELY UNSTABLE...AND
MOB VAD DATA CONTINUE TO INDICATE STRONGER LOW-LEVEL FLOW /AND
RESULTING SHEAR/ THAN NUMERICAL FORECASTS. AS SUCH...A RISK FOR
BRIEF TORNADOES AND/OR LOCALLY DAMAGING WIND GUSTS WILL PERSIST
THROUGH THIS MORNING.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 20025.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 22, 2:28 AM CDT | Mesoscale Discussion | SPC | Mobile, Washington | 2 hr |
| Mar 22, 6:49 AM CDT | Mesoscale Discussion | SPC | Mobile | 116 min |
| Mar 22, 9:53 AM CDT | Mesoscale Discussion | SPC | Baldwin, Clarke, Mobile, Washington | 67 min |
| Mar 22, 10:55 AM CDT | Tornado Watch | SPC | Baldwin, Clarke, Mobile, Monroe, Washington, Wilcox | 6 hr |
| Mar 22, 1:00 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Bibb, Butler, Chilton, Conecuh and 10 more | 60 min |
| Mar 22, 3:30 PM CDT | Mesoscale Discussion | SPC | Baldwin, Conecuh, Escambia, Mobile, Monroe, Wilcox | 60 min |
| Mar 21, 9:27 PM CDT | Mesoscale Discussion | SPC | Plaquemines, Saint Bernard | 93 min |
| Mar 21, 11:49 PM CDT | Mesoscale Discussion | SPC | Saint Bernard | 56 min |
Nearby
Tornado Watches in Mississippi, 2012Every tornado 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.