Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL6
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 676
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT SAT AUG 8 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
NORTH CENTRAL NEBRASKA
MUCH OF EASTERN SOUTH DAKOTA
EFFECTIVE THIS SATURDAY MORNING AND EVENING FROM 1115 AM UNTIL
600 PM CDT.
HAIL TO 2 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 75
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES WEST
SOUTHWEST OF ONEILL NEBRASKA TO 40 MILES NORTHEAST OF ABERDEEN
SOUTH DAKOTA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).
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.
DISCUSSION...TSTMS WILL CONTINUE TO DEVELOP ENEWD ACROSS NRN NEB
INTO SRN AND ERN SD AS FORCING FOR ASCENT SPREADS ACROSS THIS REGION
AHEAD OF A POTENT SHORTWAVE TROUGH...CURRENTLY LOCATED OVER WRN SD.
A MODERATELY UNSTABLE AIR MASS EXTENDING FROM NRN NEB INTO ERN SD
COMBINED WITH VERY STRONG EFFECTIVE BULK SHEAR /EXCEEDING 50-60 KT/
WILL SUPPORT ORGANIZED ROTATING UPDRAFTS WITH HAIL AND STRONG WIND
GUSTS EXPECTED TO BE THE PRIMARY THREAT.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 23025.
...PETERS/IMY
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW6
WW 676 SEVERE TSTM NE SD 081615Z - 082300Z
AXIS..75 STATUTE MILES EAST AND WEST OF LINE..
35WSW ONL/ONEILL NE/ - 40NE ABR/ABERDEEN SD/
..AVIATION COORDS.. 65NM E/W /30WSW ONL - 35NE ABR/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 23025.
LAT...LON 42270077 45849938 45849626 42279784
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU6.
Watch 676 Status Report Messages:
STATUS REPORT #2 ON WW 676
VALID 081925Z - 082040Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 676
..SCHNEIDER..08/08/09
ATTN...WFO...LBF...FSD...ABR...UNR...
&&
STATUS REPORT FOR WS 676
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC015-089-103-082040-
NE
. NEBRASKA COUNTIES INCLUDED ARE
BOYD HOLT KEYA PAHA
$$
SDC003-005-013-015-017-023-025-037-043-045-049-053-059-069-073-
085-089-091-109-111-115-123-082040-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
AURORA BEADLE BROWN
BRULE BUFFALO CHARLES MIX
CLARK DAY DOUGLAS
EDMUNDS FAULK GREGORY
HAND HYDE JERAULD
LYMAN MCPHERSON MARSHALL
ROBERTS SANBORN SPINK
TRIPP
$$
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.
$$
STATUS REPORT #1 ON WW 676
VALID 081735Z - 081840Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..PETERS..08/08/09
ATTN...WFO...LBF...FSD...ABR...UNR...
&&
STATUS REPORT FOR WS 676
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC015-017-031-089-103-149-081840-
NE
. NEBRASKA COUNTIES INCLUDED ARE
BOYD BROWN CHERRY
HOLT KEYA PAHA ROCK
$$
SDC003-005-009-011-013-015-017-023-025-029-035-037-039-043-045-
049-051-053-057-059-061-067-069-073-077-079-085-087-089-091-095-
097-109-111-115-121-123-081840-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
AURORA BEADLE BON HOMME
BROOKINGS BROWN BRULE
BUFFALO CHARLES MIX CLARK
CODINGTON DAVISON DAY
DEUEL DOUGLAS EDMUNDS
FAULK GRANT GREGORY
HAMLIN HAND HANSON
HUTCHINSON HYDE JERAULD
KINGSBURY LAKE LYMAN
MCCOOK MCPHERSON MARSHALL
MELLETTE MINER ROBERTS
SANBORN SPINK TODD
TRIPP
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (10%)
|
Probability of 1 or more strong (F2-F5) tornadoes
|
Low (<2%)
|
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 (60%)
|
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.