Tsunami Advisory for Washington, Warning for Oregon Coasts
ARRIVAL TIMES FOR THE INITIAL WAVE ARE ESTIMATED AT AROUND 7 AM
ESTIMATED WAVE AMPLITUDES ARE LISTED BELOW:
LONG BEACH, WA: 0.4 METER (1.3 FEET)
CLATSOP SPIT, OR: 1.37 METER (4.5 FEET)
CANNON BEACH, OR: 1.13 METER (3.7 FEET)
OCEANSIDE, OR: 1.01 METER (3.3 FEET)
BROOKINGS, OR: 1.92 METER (6.3 FEET)
Tsunami Warning – a tsunami warning is issued when a potential tsunami with significant widespread inundation is imminent or expected. Warnings alert the public that widespread, dangerous coastal flooding accompanied by powerful currents is possible and may continue for several hours after arrival of the initial wave. Warnings also alert emergency management officials to take action for the entire tsunami hazard zone. Appropriate actions to be taken by local officials may include the evacuation of low-lying coastal areas, and the repositioning of ships to deep waters when there is time to safely do so. Warnings may be updated, adjusted geographically, downgraded, or canceled. To provide the earliest possible alert, initial warnings are normally based only on seismic information. For an example of the National Weather Service (NWS) format tsunami warning CLICK HERE. For a warning cancellation, CLICK HERE.
Tsunami Advisory – a tsunami advisory is issued due to the threat of a potential tsunami which may produce strong currents or waves dangerous to those in or near the water. Coastal regions historically prone to damage due to strong currents induced by tsunamis are at the greatest risk. The threat may continue for several hours after the arrival of the initial wave, but significant widespread inundation is not expected for areas under an advisory. Appropriate actions to be taken by local officials may include closing beaches, evacuating harbors and marinas, and the repositioning of ships to deep waters when there is time to safely do so. Advisories are normally updated to continue the advisory, expand/contract affected areas, upgrade to a warning, or cancel the advisory. For an example of the NWS format tsunami advisory CLICK HERE.
Tsunami Watch – a tsunami watch is issued to alert emergency management officials and the public of an event which may later impact the watch area. The watch area may be upgraded to a warning or advisory – or canceled – based on updated information and analysis. Therefore, emergency management officials and the public should prepare to take action. Watches are normally issued based on seismic information without confirmation that a destructive tsunami is underway. For an example of the NWS format tsunami watch CLICK HERE.