National Weather Service advises funnel clouds possible this afternoon

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National Weather Service advises funnel clouds possible this afternoon

Posted on September 8, 2011. Tags: dust devils, funnel clouds, Kohala, kona, tornado, waterspouts

MEDIA RELEASE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
817 AM HST THU SEP 8 2011

A funnel cloud. Courtesy of NWS/NSSL

NIIHAU-KAUAI LEEWARD-KAUAI MOUNTAINS-OAHU SOUTH SHORE- WAIANAE COAST-OAHU NORTH SHORE-CENTRAL OAHU-WAIANAE MOUNTAINS- MOLOKAI LEEWARD-LANAI MAKAI-LANAI MAUKA-KAHOOLAWE- MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-LEEWARD HALEAKALA-KONA- KOHALA-BIG ISLAND INTERIOR-
817 AM HST THU SEP 8 2011

…FUNNEL CLOUDS POSSIBLE THIS AFTERNOON…

LIGHT WINDS WILL ALLOW SEA BREEZES TO DEVELOP OVER THE ISLANDS FROM MID-DAY THROUGH LATE AFTERNOON TODAY. THESE CONVERGING WINDS WILL COMBINE WITH MODERATE INSTABILITY TO PRODUCE CLOUDS AND A FEW SHOWERS OVER LEEWARD AND INTERIOR PORTIONS OF THE ISLANDS. AS THIS OCCURS…THERE IS A POTENTIAL FOR FUNNEL CLOUDS TO DEVELOP.

FUNNEL CLOUDS TEND TO DEVELOP BENEATH DARK…FLAT CLOUD BASES… JUST AT THE HINT OF RAIN. FUNNEL CLOUDS IN HAWAII ARE TYPICALLY SHORT-LIVED AND DO NOT PRODUCE DAMAGE. HOWEVER…IF A FUNNEL CLOUD EXTENDS TO THE GROUND…IT CAN PRODUCE LOCALIZED DANGEROUS WINDS.

What’s the difference between a funnel cloud and a tornado? What is a funnel cloud? In a tornado, a damaging circulation is on the ground–whether or not the cloud is. The phrase, “tornado on the ground,” is redundant! A tornado, by definition, is “on the ground.” A true funnel cloud rotates, but has no ground contact or debris, and is not doing damage. If it is a low-hanging cloud with no rotation, it is not a funnel cloud. Caution: tornadoes can happen without a funnel; and what looks like “only” a funnel cloud may be doing damage which can’t be seen from a distance. Some funnels are high-based and may never reach the surface. Still, since a funnel cloud might quickly become a tornado (remember rotation!), it should be reported by spotters.