Coastal Flood — Marshall Islands, Guam

2016-10-17 to 2016-10-20 · Marshall Islands, Guam

Event narrative

Lunar perigee occurred around 00Z on the 17th. This causes Spring tides across Majuro, which can increase the chance of coastal inundation at the atoll. The forecast for Majuro from the 13th to the 19th indicated the possibility of occasional coastal inundation, especially around the time of high tide during that time period. Indeed, brief inundation was observed across the atoll during those few days.

A larger period of inundation occurred on the 18th of the month. On the morning of the 18th Scatterometer data hinted at a surface trough stretching across the Marshall Islands south of Majuro. The evening pass of the Scatterometer satellite showed a wind maximum over the atoll, possibly associated with a small circulation that briefly developed on the trough. The Scatterometer data showed winds between 20 and 30 knots over Majuro. Weather observations from the Weather Office in Majuro did show winds between 10 to 18 knots with a few wind gusts around 25 knots.

A buoy observed seas going from around 5 feet at 0333Z to 7 feet at 0533Z, with the

sea height around 7 feet lasting until 0933Z, falling to 6 feet at 1003Z and returning to 5 feet at 1133Z. The period of the seas was between 4 and 7 seconds, which corresponds to wind waves. Coastal Inundation was observed at various locations across Majuro causing brief flooding of sections of road on the atoll. Some of the waves did throw rocks on some of the roads on the 18th of October.

Wider weather episode

Spring tides caused periods of coastal inundation at Majuro in the Marshall Islands

for a few days in October.

Source: NOAA Storm Events Database, event_id 664077. Narrative written by the NWS forecast office that issued the report.