NOAA/NWS Forecasting and observing of Great Lakes Rip Currents Great Lakes Rip Current Conference June 3, 2009 Dave Guenther WFO Marquette
Where we have been: Research in the hazard of rip currents began (1936) Rip current forecasting started in Miami (1991) Great Lakes organizations for beach safety established Mackinaw County Water Safety Review Team (1999) Great Lakes Beach and Pier Safety Task Force (2000) South Haven Group (name?) (2006) NOAA s national rip current initiative (2004) National Rip Current Workshop (Jacksonville) Great Lakes rip currents offically recognized nationally
Where we have been (cont) Great Lakes Rip Current Workshops started (2002) COMET R C training modules developed (2004-2006) National Rip Current Task Force (2004) Adding rip current information in HWO (2005) NWS started issuing Lake Shore Hazard Message / WFO Duluth started issuing Surf Forecasts (2008) Surf Forecasts started at 3 more NWS GL offices (GRR/IWX/CHI) forecasts. (2009) National Rip Current Seminar Miami (2010)
National Rip Current Task Force Partners NWS, USLSA, NOAA Sea Grant Established flag standardization Developed national safety sign Established three tiered hazard levels Recommendation using Surf Forecasts for dissemination of rip current information.
Southeast Florida Rip Current Fatalities 25 20 15 10 '79 '81 '83 '85 '87 '89 5 0 '91 '93 '95 '97 '99 '01 '03 1979-2003
Rip Currents Rip currents are narrow channels of water flowing out past the surf zone that can pull even strong swimmers into deep water beyond the offshore sand bar Second deadiest weather related phenomena
It s a problem?
Rip Current Events documented 2008-7 drowning deaths 2008-11 rescues recorded Recent years drowning deaths 2007 9 2006 6 2005 9 2004 6 2003 13 2002 6 Average 7.1/year
Documented Rip Current Drowning Deaths (2002-2008) Lake Superior Lake Michigan Lake Erie Lake Huron Lake Ontario Images courtesy of NASA
Where rip currents occur Waves moving normal to shore. Waves moving at an angle to shore. Waves encountering jetties, groins, or piers. Related Long shore current?
Picnic Rocks - Marquette Photo courtesy of USGS
Grand Sable Dunes near Grand Marais, MI Picture courtesy of Don Rolfson
Berrien County, Michigan
Definition of Risks NWSI 10-310
Rip Current Products HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MARQUETTE MI 435 AM EDT SAT JUNE 18 2005 MIZ001>007-009>014-084-085-191200- ALGER-BARAGA-DELTA-DICKINSON-GOGEBIC-IRON-KEWEENAW-LUCE-MARQUETTE- MENOMINEE-NORTHERN HOUGHTON-NORTHERN SCHOOLCRAFT-ONTONAGON- SOUTHERN HOUGHTON-SOUTHERN SCHOOLCRAFT- 435 AM EDT SAT JUNE 18 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL UPPER MICHIGAN.. DAY ONE...TODAY AND TONIGHT ISOLATED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING...EXCEPT ON THE KEWEENAW PENINSULA. THESE STORMS WILL DROP BRIEF HEAVY RAIN AND MAY ALSO PRODUCE GUSTY WINDS TO 40 MPH AND HAIL UP TO ONE HALF INCH IN DIAMETER. THERE WILL BE AN MODERATE RISK OF RIP CURRENTS ALONG THE LAKE SUPERIOR SHORE FROM MARQUETTE TO GRAND MARAIS THIS AFTERNOON. DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.. SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. ADDITIONAL WEATHER INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL: HTTP://WWW.WEATHER.GOV/MQT (ALL LOWER CASE)
SURF ZONE FORECAST FOR MINNESOTA NATIONAL WEATHER SERVICE DULUTH MN 354 AM CDT FRI AUG 1 2008. MNZ037-WIZ001-012115- CARLTON/SOUTHERN ST. LOUIS-DOUGLAS- INCLUDING THE BEACHES OF DULUTH SUPERIOR 354 AM CDT FRI AUG 1 2008.TODAY... SKY/WEATHER...MOSTLY SUNNY (30-40 PERCENT). MAX TEMPERATURE...78-83. BEACH WINDS...NORTHWEST WINDS 10 TO 15 MPH. SURF...2 FEET OR LESS. WATER TEMPERATURE..63 DEGREES. RIP CURRENT RISK...LOW...HOWEVER STRONG CURRENTS CAN OCCUR NEAR PIERS AND JETTIES. ALWAYS HAVE FLOATATION DEVICE WITH YOU IN THE WATER. $$
LAKESHORE HAZARD MESSAGE NATIONAL WEATHER SERVICE MARQUETTE MI 405 AM EDT SAT SEP 20 2008 MODERATE RISK OF RIP CURRENTS LATE THIS AFTERNOON AND EARLY EVENING FROM MARQUETTE TO GRAND MARAIS MI NORTH WINDS OF 10 TO 20 MPH OVER EASTERN LAKE SUPERIOR THIS AFTERNOON WILL BUILD WAVES TO 4 TO 6 FEET ALONG THE LAKE SUPERIOR BEACHES FROM MARQUETTE TO GRAND MARAIS MI. THIS CONDITION WILL CONTINUE INTO THE EARLY EVENING HOURS BEFORE THE WAVES AND RISK SUBSIDE. WITH A MODERATE RISK OF RIP CURRENT IT IS RECOMMENDED THAT ONLY EXPERIENCED SWIMMERS SHOULD ENTER THE WATER. RIP CURRENTS ARE STRONG NARROW CHANNELS OF WATER THAT FLOW AWAY FROM THE BEACH. IF CAUGHT IN A RIP CURRENT SWIM PARALLEL TO THE SHORE UNTIL OUT THE CURRENT THEN SWIM BACK TO THE SHORE.
Increased Observational Data Open Lake buoys C-MAN sites GLOS NOS tide gages Aviation observing stations GLERL sites Acoustical Doppler Profilers
Summary of most common ingredients Wave action, either wind or seiche related Longer periods waves are preferred, 6 sec or greater, but not required Onshore wind, the stronger the more the risk Closer to directly onshore the wind and waves are the greater the risk Waves greater than 3 feet in the swimming season with onshore flow, include a risk or rip currents in the HWO Lake level
Wave Height/Direction
Marquette RC Checklist GFE procedure
Rip current web sites http://www.ripcurrents.noaa.gov/ http://www.usla.org/beach_safety/rip_current1.asp http://www.respectthepower.org/ http://www.seagrant.umn.edu/coastal_communities/r ip
Questions and Comments Grand Sable Dunes near Grand Marais, MI Picture courtesy of Don Rolfson