(Press Release) — On Wednesday afternoon, the CNMI Office of Homeland Security and Emergency Management, in coordination with the National Weather Service-Guam, received reports of a funnel cloud sighting in the Southern Saipan area. It was not known if the funnel cloud had reached the ocean surface, in which case it would become a waterspout.
Waterspouts are similar to tornadoes over water, but are much weaker than tornadoes since tornadoes are formed in strong thunderstorms with strong updrafts. Fair-weather waterspouts form in light wind conditions, so they normally move little. Typically, fair waterspouts dissipate rapidly when they make landfall and rarely penetrate far inland.
Fair-weather waterspouts, common in the Marianas, are usually less dangerous. The term fair weather comes from the fact that this type of waterspout forms during fair, relatively calm weather, often early to mid-morning and sometimes late afternoon. Waterspouts usually form along dark flat bases of a line of developing cumulus clouds, but, in rare cases, may be seen near thunderstorms.
Waterspouts begin to develop on the surface of the water, visible as a darkened patch of choppy water and swirling wind. A funnel may also be present, extending from the base of the cloud. A waterspout reaches its mature stage when the entire rotating column of air is fully visible from the sea to the cloud.
The best way to avoid a waterspout is to move at a 90-degree angle to its apparent movement. Never move closer, attempt to boat through, or drive through (in the case of a waterspout moving on shore) a waterspout to investigate. Wind speeds may reach 50-70 mph, potentially damaging property or causing injuries.
Waterspout safety
• Listen for special marine warnings about waterspout sightings that are broadcast on NOAA Weather Radio.
• Watch the sky for certain types of clouds. In the wet season, with light winds, look for a possible waterspout underneath a line of cumulus clouds with dark, flat bases.
• If a waterspout is sighted, immediately head at a 90-degree angle from the apparent motion of the waterspout.
• Never try to navigate through a waterspout. Although waterspouts are weaker than tornadoes, they can still produce significant damage to you and your boat.
For more information, contact HSEM Public Information Officer Bernard Villagomez at [email protected] or call (670) 287-7106.
