Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL4
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 474
NWS STORM PREDICTION CENTER NORMAN OK
1155 PM CDT THU JUN 18 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
MUCH OF NEBRASKA
EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1155 PM
UNTIL 600 AM 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 85
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 65 MILES WEST
SOUTHWEST OF MULLEN NEBRASKA TO 65 MILES NORTHEAST OF GRAND
ISLAND NEBRASKA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).
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 470...WW 471...WW
472...WW 473...
DISCUSSION...STORMS CONTINUE TO EXPAND ACROSS FAR NERN CO AND INTO
NEB ATTM...AS STRENGTHENING SLY LOW-LEVEL JET ACROSS WRN KS YIELDS
INCREASING ISENTROPIC ASCENT ACROSS NEB N OF A SURFACE WARM FRONT
OVER KS/SERN NEB. WITH AMPLE INSTABILITY AND DEEP-LAYER SHEAR
SUFFICIENT FOR SUPERCELLS...LARGE HAIL AND DAMAGING WIND THREAT
SHOULD EXPAND WITH TIME IN CONJUNCTION WITH INCREASING STORM
COVERAGE OVERNIGHT.
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 25035.
...GOSS
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW4
WW 474 SEVERE TSTM NE 190455Z - 191100Z
AXIS..85 STATUTE MILES NORTH AND SOUTH OF LINE..
65WSW MHN/MULLEN NE/ - 65NE GRI/GRAND ISLAND NE/
..AVIATION COORDS.. 75NM N/S /49NE SNY - 44ENE OBH/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 25035.
LAT...LON 42900223 42869743 40409743 40450223
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU4.
Watch 474 Status Report Messages:
STATUS REPORT #2 ON WW 474
VALID 190835Z - 190940Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 ENE MCK
TO 20 S BUB TO 10 NE OFK.
..GUYER..06/19/09
ATTN...WFO...GID...OAX...LBF...
&&
STATUS REPORT FOR WS 474
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC011-119-139-141-190940-
NE
. NEBRASKA COUNTIES INCLUDED ARE
BOONE MADISON PIERCE
PLATTE
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 474
VALID 190745Z - 190840Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..GUYER..06/19/09
ATTN...WFO...GID...OAX...LBF...
&&
STATUS REPORT FOR WS 474
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC001-003-009-011-015-017-019-023-029-031-035-041-047-049-059-
063-071-073-077-079-081-085-089-091-093-099-101-103-107-111-113-
115-117-119-121-125-135-137-139-141-143-149-163-171-175-183-185-
190840-
NE
. NEBRASKA COUNTIES INCLUDED ARE
ADAMS ANTELOPE BLAINE
BOONE BOYD BROWN
BUFFALO BUTLER CHASE
CHERRY CLAY CUSTER
DAWSON DEUEL FILLMORE
FRONTIER GARFIELD GOSPER
GREELEY HALL HAMILTON
HAYES HOLT HOOKER
HOWARD KEARNEY KEITH
KEYA PAHA KNOX LINCOLN
LOGAN LOUP MCPHERSON
MADISON MERRICK NANCE
PERKINS PHELPS PIERCE
PLATTE POLK ROCK
SHERMAN THOMAS VALLEY
WHEELER YORK
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
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 (60%)
|
Probability
of 1 or
more hailstones > 2 inches
|
Mod (30%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (90%)
|
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 
