Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL2
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 642
NWS STORM PREDICTION CENTER NORMAN OK
540 PM CDT THU JUL 30 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
MUCH OF NORTHERN AND CENTRAL ALABAMA
PARTS OF SOUTHERN MIDDLE TENNESSEE
EFFECTIVE THIS THURSDAY AFTERNOON FROM 540 PM UNTIL MIDNIGHT 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 60
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTH
SOUTHEAST OF TUSCALOOSA ALABAMA TO 45 MILES NORTH OF HUNTSVILLE
ALABAMA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).
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 639...WW 640...WW 641...
DISCUSSION...SQUALL LINE WITH EMBEDDED BOWS MOVING RAPIDLY ENEWD
ACROSS NRN MS INTO AL. WITH A VERY MOIST AND UNSTABLE AIR MASS
COUPLED WITH 30-35 KT OF SHEAR...POTENTIAL FOR DAMAGING WINDS WILL
CONTINUE ACROSS THE WATCH. ISOLATED SUPERCELLS ALSO POSSIBLE ALONG
AND AHEAD OF THE LINE WITH A THREAT OF BRIEF TORNADOES.
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 24035.
...HALES
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW2
WW 642 SEVERE TSTM AL TN 302240Z - 310500Z
AXIS..60 STATUTE MILES EAST AND WEST OF LINE..
45SSE TCL/TUSCALOOSA AL/ - 45N HSV/HUNTSVILLE AL/
..AVIATION COORDS.. 50NM E/W /56WNW MGM - 50NE MSL/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 24035.
LAT...LON 32618836 35298783 35298572 32618629
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU2.
Watch 642 Status Report Messages:
STATUS REPORT #3 ON WW 642
VALID 310135Z - 310240Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SW CHA TO
40 NNW MSL.
..HURLBUT..07/31/09
ATTN...WFO...BMX...HUN...
&&
STATUS REPORT FOR WS 642
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TNC051-310240-
TN
. TENNESSEE COUNTIES INCLUDED ARE
FRANKLIN
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #2 ON WW 642
VALID 310105Z - 310240Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SW RMG TO
25 WNW MSL.
..HURLBUT..07/31/09
ATTN...WFO...BMX...HUN...
&&
STATUS REPORT FOR WS 642
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ALC049-071-077-083-089-095-103-310240-
AL
. ALABAMA COUNTIES INCLUDED ARE
DEKALB JACKSON LAUDERDALE
LIMESTONE MADISON MARSHALL
MORGAN
$$
TNC051-103-127-310240-
TN
. TENNESSEE COUNTIES INCLUDED ARE
FRANKLIN LINCOLN MOORE
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 642
VALID 302340Z - 310040Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..HURLBUT..07/30/09
ATTN...WFO...BMX...HUN...
&&
STATUS REPORT FOR WS 642
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ALC007-009-033-043-049-055-057-059-071-073-075-077-079-083-089-
093-095-103-107-115-117-121-125-127-133-310040-
AL
. ALABAMA COUNTIES INCLUDED ARE
BIBB BLOUNT COLBERT
CULLMAN DEKALB ETOWAH
FAYETTE FRANKLIN JACKSON
JEFFERSON LAMAR LAUDERDALE
LAWRENCE LIMESTONE MADISON
MARION MARSHALL MORGAN
PICKENS ST. CLAIR SHELBY
TALLADEGA TUSCALOOSA WALKER
WINSTON
$$
TNC051-103-127-310040-
TN
. TENNESSEE COUNTIES INCLUDED ARE
FRANKLIN LINCOLN MOORE
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (20%)
|
Probability of 1 or more strong (F2-F5) tornadoes
|
Low (5%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (40%)
|
Probability of 1 or more wind events > 65 knots
|
Mod (30%)
|
Hail
Probability of 10 or more severe hail events
|
Mod (30%)
|
Probability
of 1 or
more hailstones > 2 inches
|
Low (20%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (80%)
|
For each watch, probabilities for particular events inside the watch
(listed above in each table) are determined by the issuing forecaster.
The "Low" category contains probability values ranging from less than 2%
to 20% (F2-F5 tornadoes), less than 5% to 20% (all other probabilities),
"Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.
High values are bolded and lighter in color to provide awareness of
an increased threat for a particular event.
weather.gov 
