Supercell over the Atlantic Ocean near Southport, NC

May 29, 2001

Around 2:40 pm May 29, 2001, a supercell developed over the Atlantic Ocean off the Brunswick county shore. This supercell moved east around 25 knots and brushed the Brunswick county coastline, hitting Bald Head Island the hardest. Fortunately the worst of the storm remained offshore.

The storm displayed an incredible hook echo on radar. This feature is easily picked out in the reflectivity imagery (top left) as a cyclonic curl on the southwest edge of the storm. In the storm-relative velocity imagery (top right), a tight couplet of inbound/outbound (red/ green) winds can be seen at the same location as the hook echo. This further strengthens the belief this cell may have been producing a large waterspout at this time. This is best seen at 18:49Z (2:49 pm EDT) when the radar actually alarmed for a TVS - tornado vortex signature. If a waterspout was present, this would be very different than most waterspouts seen along the Carolina coastlines during the summer months. Most waterspouts are small, relatively weak circulations which form under large cumulus clouds - sometimes without even any rainfall present! Based on radar, this would have likely been a tornadic waterspout - a true tornado which just happened to form over water. Any vessels in the water near this storm could have been in grave danger.

A special marine warning was issued for this storm. Special Marine Warnings are the marine equivalent of severe thunderstorm or tornado warnings for those of us on land. They warn of impending danger from thunderstorms or brief high winds. Everyone who spends time on a boat should keep a NOAA Weather Radio onboard to receive these warnings, and other weather forecasts.

If you or someone you know observed this storm, or has pictures or second-hand accounts, please email the information using the link at the bottom of this page.

Please allow 2 to 3 minutes for this animation to load if you are on a dial-up connection!
WHUS52 KILM 291902
SMWILM
AMZ250-252-292015-

SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE WILMINGTON NC
259 PM EDT TUE MAY 29 2001

THE NATIONAL WEATHER SERVICE IN WILMINGTON NC HAS ISSUED A 

* SPECIAL MARINE WARNING FOR...
  THE COASTAL WATERS FROM

  SURF CITY TO CAPE FEAR OUT 40 NM

* UNTIL 415 PM EDT

* AT 255 PM EDT DOPPLER RADAR INDICATED A POSSIBLE WATERSPOUT
2 MILES SOUTH OF CAPE FEAR...MOVING EAST AT 30 MPH.

INTENSE LIGHTNING IS OCCURRING WITH THIS STORM. IF CAUGHT ON THE
WATER STAY BELOW DECK IF POSSIBLE. KEEP AWAY FROM UNGROUNDED
OBJECTS.

WATERSPOUTS ARE CAPABLE OF WINDS TO 80 KNOTS WHICH CAN CAPSIZE BOATS.
AVOID WATERSPOUTS BY MOVING AWAY FROM THE PATH OF THE STOR. WEAKER
WATERSPOUTS ARE POSSIBLE UNDER CLOUDS WITH LITTLE RAIN AND SHOULD
ALSO BE AVOIDED.

REPORT SEVERE WEATHER TO THE COAST GUARD. THEY WILL RELAY YOUR REPORT
TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN WILMINGTON NC.

.END

$$

TM

LAT...LON 3404 7840 3391 7825 3427 7773 3447 7796

Page created 29 May 2001 by Tim Armstrong