Alert archive / Louisiana / Tornado Watches in 2007
Tornado Watch 190
The Storm Prediction Center issued this tornado watch at Apr 26, 2007, 12:41 AM CDT for 5 counties in Alabama; 13 parishes in Louisiana; 9 counties in Mississippi. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2007, 12:41 AM CDT (05:41 UTC)
- Expired
- Apr 26, 2007, 8:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 27 counties
Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Mobile County, AL, Washington County, AL, Ascension Parish, LA, Assumption Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS
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
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 6:18 AM CDT | Tornado Warning | LIX | Harrison, Jackson | 27 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 00:00Z, 5.7 hours before the alert went out and 14 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
- 583 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 1060 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 77 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 260542
SEL0
SPC WW 260542
ALZ000-LAZ000-MSZ000-CWZ000-261300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 190
NWS STORM PREDICTION CENTER NORMAN OK
1240 AM CDT THU APR 26 2007
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHWEST ALABAMA
SOUTHEAST LOUISIANA
SOUTHEAST MISSISSIPPI
COASTAL WATERS
EFFECTIVE THIS THURSDAY MORNING FROM 1240 AM UNTIL 800 AM 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 NORTH AND SOUTH OF A LINE FROM 45 MILES SOUTHWEST OF HOUMA
LOUISIANA TO 50 MILES NORTHEAST OF MOBILE ALABAMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).
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...FAVORABLE SHEAR PROFILES/HODOGRAPHS ALONG WITH A MOIST
MODERATELY UNSTABLE AIR MASS SUPPORT SUPERCELL POTENTIAL WITH
CURRENT THUNDERSTORMS MOVING EWD ACROSS WATCH. AS LARGE SCALE
TROUGH SHIFTS EWD ACROSS LWR/MID MS RIVER VALLEY...THREAT OF
SUPERCELLS/ISOLATED TORNADOES WILL MOVE EWD INTO SWRN AL.
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 25030.
...HALESSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 11:50 PM CDT | Mesoscale Discussion | SPC | Mobile, Washington | 85 min |
| Apr 26, 4:46 AM CDT | Mesoscale Discussion | SPC | Baldwin, Choctaw, Clarke, Marengo, Mobile, Monroe and 1 more | 89 min |
| Apr 26, 7:12 AM CDT | Mesoscale Discussion | SPC | Baldwin, Clarke, Mobile, Monroe, Washington | 93 min |
| Apr 26, 2:12 PM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Chambers, Coffee, Covington, Crenshaw and 12 more | 63 min |
| Apr 26, 2:42 PM CDT | Tornado Watch | SPC | Barbour, Bullock, Coffee, Dale, Geneva, Henry and 3 more | 3 hr |
| Apr 26, 4:33 PM CDT | Mesoscale Discussion | SPC | Cherokee, DeKalb, Etowah, Jackson, Marshall | 57 min |
| Apr 26, 4:53 PM CDT | Tornado Watch | SPC | DeKalb, Jackson, Marshall | 5 hr |
| Apr 26, 5:26 PM CDT | Mesoscale Discussion | SPC | Henry, Houston | 64 min |
Nearby
Tornado Watches in Louisiana, 2007Tornado Watches in Mississippi, 2007Tornado Watches in Alabama, 2007Every tornado watch in 2007
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.