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Coastal Flooding
Coastal Flood Watch - Issued when moderate or severe coastal
flooding is possible
within 12 to 36 hours.
Coastal Flood Warning - Issued when moderate or severe coastal
flooding is expected within 12 hours.
Coastal Flooding Water Level Definitions
| Location |
"Minor Tidal
Overflow" |
"Coastal Flooding" |
| Aberdeen *# |
13.5 - 13.9 feet |
14.0 feet and
above |
| Bellingham @ |
11.5 - 12.4 feet |
12.5 feet and
above |
| Seattle |
13.5 - 14.4 feet |
14.5 feet and
above |
* A Coastal Flood Warning will
also be issued for the Central Coast when swell of 25 feet or
higher are expected to coincide with an observed tide of 12.0
feet or higher at Aberdeen.
# A Coastal Flood Warning will
also be issued for the Central Coast anytime that large waves
are expected to cause extensive beach run-up, flooding, or
damage of any kind, regardless of swell height.
@ A Coastal Flood Warning may
be issued for western Whatcom County if large waves of 8-10 feet
or more moving down from the Strait of Georgia (generated by
strong northwest winds) are expected to impact the Sandy Point
and Birch Bay areas
during an astronomical high tide.
High Surf Advisory
A High Surf Advisory
is issued for the Central and North Washington Coast when the
following conditions are expected within 12 hours:
1) From May 15
through the first episode of autumn...swell of 15-24 feet are
expected to impact the coastline, OR
2) After the first
episode of autumn through May 14...swell of 20-24 feet are
expected to impact the coastline.
High Surf Warning
A High Surf Warning
is issued for the Central and North Washington Coast when swell
of 25 feet or higher are expected to impact the coastline within
12 hours (in the absence of coastal flooding).
Dense Fog Advisory
A dense
fog advisory is issued when widespread fog is expected to
reduce visibilities to 1/4 mile or less over a large area for an
extended period of time (more than 3 hours).
Severe Thunderstorm
Warning
A
severe thunderstorm warning is issued when severe thunderstorms
are occurring
or imminent in the warning area.
Severe
thunderstorms are defined as follows:
1) Winds
of 58 mph or higher, AND/OR
2) Hail
3/4 of an inch in diameter or larger.
Severe Thunderstorm Watch
A
severe thunderstorm watch is issued when severe thunderstorms
are possible in
and near the watch area. It does not mean that they will occur.
It only means they
are possible.
Tornado Warning
A
tornado warning is issued when a tornado is imminent or
occurring.
Tornado Watch
A
tornado watch is issued when severe thunderstorms and tornadoes
are possible in
and near the watch area. It does not mean that they will occur.
It only means they
are possible.
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