Only a short time ago (9:45 pm Pacific) tsunamis caused by a 8.9 Earthquake hit Japan. Another strong earthquake is expected.
HAWAII 1ST WAVE ARRIVAL IS 3:07 AM (local time)
Here are the information sources I have found useful so far:
Tsunami may be higher than some Pacific Islands and wash over them
US National Weather Service Tsunami Warning
NOAA National Weather Service Pacific Tsunami Warning Center
NOAA Tsunami propagation path model
NOAA Tsunami West Coast arrival times
NOAA map of tsunami effect on Pacific Ocean
ZDNet Japan Data Center and Cloud Health Report (translated)