Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL5
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 575
NWS STORM PREDICTION CENTER NORMAN OK
850 PM PDT SUN JUL 12 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
NORTHERN IDAHO
EASTERN WASHINGTON
EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 850 PM UNTIL
200 AM PDT.
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 50
STATUTE MILES EAST AND WEST OF A LINE FROM 95 MILES NORTH OF
SPOKANE WASHINGTON TO 30 MILES SOUTHWEST OF PULLMAN WASHINGTON.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).
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...A CLUSTER OF HIGH-BASED THUNDERSTORMS WILL SPREAD
NORTHWARD THROUGH THE NIGHT ACROSS EASTERN WA AND INTO NORTHERN ID.
STRONG WINDS ALOFT AHEAD OF AN INTENSE UPPER TROUGH...COMBINED WITH
A DEEP MIXED BOUNDARY LAYER WILL PROMOTE A RISK OF LOCALLY DAMAGING
WINDS WITH THE STORMS.
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 20030.
...HART
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW5
WW 575 SEVERE TSTM ID WA 130350Z - 130900Z
AXIS..50 STATUTE MILES EAST AND WEST OF LINE..
95N GEG/SPOKANE WA/ - 30SW PUW/PULLMAN WA/
..AVIATION COORDS.. 45NM E/W /78WSW YXC - 67S GEG/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 400. MEAN STORM MOTION VECTOR 20030.
LAT...LON 48991643 46431651 46431862 48991862
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU5.
Watch 575 Status Report Messages:
STATUS REPORT #1 ON WW 575
VALID 130600Z - 130740Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 60 NE GEG TO
30 E OMK.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1539
..SPC..07/13/09
ATTN...WFO...OTX...
&&
STATUS REPORT FOR WS 575
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IDC017-021-130740-
ID
. IDAHO COUNTIES INCLUDED ARE
BONNER BOUNDARY
$$
WAC019-051-065-130740-
WA
. WASHINGTON COUNTIES INCLUDED ARE
FERRY PEND OREILLE STEVENS
$$
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 (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 
