Alert archive / Alabama / Tornado Watches in 2013
Tornado Watch 98
The Storm Prediction Center issued this tornado watch at Apr 11, 2013, 1:30 PM CDT for 12 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2013, 1:30 PM CDT (18:30 UTC)
- Expired
- Apr 11, 2013, 9:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Baldwin County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL
The radar
The Mobile radar (KMOB), 94 km from the middle of the area, began a volume at 18:30 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
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 1:41 PM CDT | Severe Thunderstorm Warning | MOB | Choctaw | 64 min |
| Apr 11, 2:16 PM CDT | Tornado Warning | MOB | Choctaw | 44 min |
| Apr 11, 2:18 PM CDT | Tornado Warning | MOB | Washington | 42 min |
| Apr 11, 2:36 PM CDT | Severe Thunderstorm Warning | MOB | Choctaw, Clarke | 39 min |
| Apr 11, 2:44 PM CDT | Severe Thunderstorm Warning | MOB | Washington | 31 min |
| Apr 11, 5:27 PM CDT | Flash Flood Warning | MOB | Clarke | 6 hr |
| Apr 11, 5:27 PM CDT | Severe Thunderstorm Warning | MOB | Mobile | 33 min |
| Apr 11, 5:43 PM CDT | Severe Thunderstorm Warning | MOB | Baldwin, Mobile | 32 min |
| Apr 11, 6:06 PM CDT | Severe Thunderstorm Warning | MOB | Baldwin, Escambia | 24 min |
| Apr 11, 7:43 PM CDT | Severe Thunderstorm Warning | MOB | Okaloosa, Santa Rosa | 62 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
Birmingham, AL (KBMX), launched 12:00Z, 6.5 hours before the alert went out and 218 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
- 35 J/kg
- Mixed-layer CIN
- -291 J/kg
- Mixed-layer LCL
- 635 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 143 m²/s²
- 0-3 km storm-relative helicity
- 169 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
894
WWUS20 KWNS 111829
SEL8
SPC WW 111829
ALZ000-FLZ000-CWZ000-120100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 98
NWS STORM PREDICTION CENTER NORMAN OK
130 PM CDT THU APR 11 2013
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL ALABAMA
THE WESTERN FLORIDA PANHANDLE
COASTAL WATERS
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 130 PM UNTIL
800 PM CDT.
TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF EVERGREEN
ALABAMA TO 35 MILES SOUTH SOUTHEAST OF MOBILE ALABAMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU8).
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.
OTHER WATCH INFORMATION...CONTINUE...WW 95...WW 96...WW 97...
DISCUSSION...A LINE OF SEVERE STORMS ALONG THE COLD FRONT IN SRN MS
WILL MOVE EWD INTO SW AL BY ABOUT 20Z...WHILE OTHER PRE-FRONTAL
SHOWERS OVER S CENTRAL AL POTENTIALLY DEVELOP INTO THUNDERSTORMS.
VERTICAL SHEAR AND INSTABILITY ARE FAVORABLE FOR MAINTENANCE OF THE
LINE OF STORMS...AS WELL AS PRE-FRONTAL SUPERCELL DEVELOPMENT. A
FEW TORNADOES...DAMAGING WINDS...AND ISOLATED LARGE HAIL ARE ALL
POSSIBLE THROUGH THE AFTERNOON.
AVIATION...TORNADOES AND 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 25035.
...THOMPSONSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 10:41 AM CDT | Mesoscale Discussion | SPC | Colbert, Cullman, Fayette, Franklin, Greene, Hale and 12 more | 2 hr |
| Apr 11, 11:56 AM CDT | Tornado Watch | SPC | Autauga, Bibb, Blount, Chilton, Colbert, Coosa and 31 more | 7 hr |
| Apr 11, 12:59 PM CDT | Mesoscale Discussion | SPC | Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 5 more | 91 min |
| Apr 11, 2:21 PM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Chilton, Coosa, Cullman and 12 more | 84 min |
| Apr 11, 3:26 PM CDT | Mesoscale Discussion | SPC | Chambers, Cleburne, Lee, Randolph, Russell | 94 min |
| Apr 11, 3:45 PM CDT | Tornado Watch | SPC | Barbour, Bullock, Calhoun, Chambers, Cherokee, Clay and 9 more | 6 hr |
| Apr 11, 5:03 PM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Geneva, Henry, Houston | 2 hr |
| Apr 11, 5:35 PM CDT | Mesoscale Discussion | SPC | Baldwin, Butler, Conecuh, Covington, Crenshaw, Escambia and 2 more | 115 min |
| Apr 11, 5:54 PM CDT | Mesoscale Discussion | SPC | Autauga, Bullock, Calhoun, Chambers, Cherokee, Clay and 11 more | 96 min |
| Apr 10, 8:28 PM CDT | Tornado Watch | SPC | Benton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 5 more | 7 hr |
| Apr 10, 9:14 PM CDT | Mesoscale Discussion | SPC | Adams, Claiborne, Holmes, Humphreys, Issaquena, Leflore and 5 more | 2 hr |
| Apr 10, 11:08 PM CDT | Mesoscale Discussion | SPC | DeSoto, Marshall, Panola, Tate, Tunica | 97 min |
| Apr 11, 6:55 AM CDT | Mesoscale Discussion | SPC | Adams, Amite, Claiborne, Copiah, Covington, Forrest and 28 more | 65 min |
| Apr 11, 8:00 AM CDT | Tornado Watch | SPC | Amite, Clarke, Copiah, Covington, Forrest, George and 24 more | 8 hr |
| Apr 11, 12:53 PM CDT | Mesoscale Discussion | SPC | Forrest, George, Greene, Hancock, Harrison, Jackson and 4 more | 82 min |
Nearby
Tornado Watches in Alabama, 2013Tornado Watches in Florida, 2013Every tornado watch in 2013
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.