Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL9
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 489
NWS STORM PREDICTION CENTER NORMAN OK
240 PM MDT SUN JUN 21 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
EASTERN IDAHO
NORTHERN INTO CENTRAL UTAH
FAR SOUTHWEST WYOMING
EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 240 PM UNTIL 900
PM MDT.
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 65
STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHEAST OF
DUGWAY UTAH TO 45 MILES NORTHEAST OF POCATELLO IDAHO. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).
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 488...
DISCUSSION...SEVERE THUNDERSTORMS ARE ONGOING THIS AFTERNOON IN TWO
CLUSTERS...ONE OVER E-CENTRAL UT AND ANOTHER FROM ERN ID INTO FAR
NERN NV. ACTIVITY WILL LIKELY CONTINUE FOR SEVERAL HOURS WITH
THREATS OF LARGE HAIL AND ISOLATED DAMAGING WINDS GIVEN MODEST
INSTABILITY AND EFFECTIVE SHEAR FROM 40-50 KT. EXPECT STORMS MOVING
ENEWD ALONG WRN BAND WILL PERSIST THE LONGEST THIS EVENING INTO ERN
ID/NRN UT...WITH STRONGER STORMS EVOLVING INTO SUPERCELLS AND
ORGANIZED LINES/CLUSTERS.
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 400. MEAN STORM
MOTION VECTOR 23020.
...EVANS
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW9
WW 489 SEVERE TSTM ID UT WY 212040Z - 220300Z
AXIS..65 STATUTE MILES EAST AND WEST OF LINE..
25SE DPG/DUGWAY UT/ - 45NE PIH/POCATELLO ID/
..AVIATION COORDS.. 55NM E/W /38N DTA - 43NE PIH/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 400. MEAN STORM MOTION VECTOR 23020.
LAT...LON 39911381 43361326 43361066 39911137
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU9.
Watch 489 Status Report Messages:
STATUS REPORT #2 ON WW 489
VALID 220130Z - 220240Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 N EVW TO
45 ESE MLD TO 15 S JAC.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1269
THE SEVERE THREAT APPEARS TO BE WANING RATHER QUICKLY ACROSS THE
REMAINDER OF WW 489...WITH WW CANCELLATION POSSIBLE BEFORE 03Z
EXPIRATION TIME.
..SMITH..06/22/09
ATTN...WFO...PIH...SLC...
&&
STATUS REPORT FOR WS 489
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IDC007-220240-
ID
. IDAHO COUNTIES INCLUDED ARE
BEAR LAKE
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 489
VALID 220005Z - 220140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SE ENV TO
35 W OGD TO 20 WNW MLD TO 20 ESE IDA.
..SMITH..06/22/09
ATTN...WFO...PIH...SLC...
&&
STATUS REPORT FOR WS 489
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IDC005-007-019-029-041-071-220140-
ID
. IDAHO COUNTIES INCLUDED ARE
BANNOCK BEAR LAKE BONNEVILLE
CARIBOU FRANKLIN ONEIDA
$$
UTC005-007-011-013-029-033-035-043-045-049-051-057-220140-
UT
. UTAH COUNTIES INCLUDED ARE
CACHE CARBON DAVIS
DUCHESNE MORGAN RICH
SALT LAKE SUMMIT TOOELE
UTAH WASATCH WEBER
$$
WYC041-220140-
WY
. WYOMING COUNTIES INCLUDED ARE
UINTA
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
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 (5%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (30%)
|
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 (70%)
|
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 
