A Basic Guide to Marine Weather Safety 4.22.09, 7:02AM ET

Check out this free guide to marine outdoor weather forecast and activity planning for small craft, by meteorologist Ben Alonzo - Get to know the tools you can use to alert you of dangerous weather, warning signs, and resources to plan your day out on the water. Learn how to stay clear of dangerous weather and plan around Mother Nature.

INTRODUCTION

This article is an overview of terminology, science, and marine equipment used to safely navigate your craft in large lakes or during open-ocean traveling (for small craft under 25 feet length). Please be sure to also consider your regions coast guard information or marine safety organization as another source of information including real time hazardous weather alerts.

Boating is a popular outdoor activity especially in states surrounded by many lakes or coastal communities. Whether you are in open-ocean or on the lake for the weekend it's always a good idea to keep a close eye on the weather. While there are everyday hazardous involved in boating one often overlooked factor is the atmosphere. You remember to put sun screen on but didn't check the weather. It's clear now, but you're in for a big surprise soon! Don't let your guard down. Consider all the hazards and plan to do whatever you can to reduce risk or avoid trouble. Part of this planning is to know how to recognize dangerous weather and what to do when storms move into your area. Keeping alert, aware, and prepared for dangerous marine weather can help you make the most of your day on the water!

BEFORE THE STORM

Your best bet is to avoid trouble weather. You can do this by first developing a plan of action to take before the storm. The plan should involve what to do, where to go, and when. On land you may take cover in a sturdy structure or shelter - however this isn't a option if you're out on the water. Other factors will also make the situation worse such as high wind damaging your boat or blowing away luggage/tools and of course large waves - which can be life threatening. Always consider the weather before you plan on going out on the water.

Make your plan before the storm. Watch your local TV station and check online for a 5day forecast of the area you plan to boat in. During the day you depart on your craft, check the weather forecast. Even if there is a chance of storms, consider the dangers. You should have a plan of action before the storm hits. Never wait to plan when you are caught. This often results in panic and making the situation worse.

The Coast Guard and other agencies usually require a minimum safety equipped vessel. This means you should have a life vest or PFD for each person aboard. You should also have a fire extinguisher, first aid, and flare kit. One huge important item is to have a weather radio no matter what size of your boat is. This will allow you to get weather information while you're on the water. You can also set it to silently monitor the weather frequency and then sound an alert when dangerous weather approaches.

Having a weather radio is great - however - and this is a big however, never depend on the radio itself. You need to be aware of your surroundings. Even if it's clear, pay attention to the distance, wind, wave height, etc. If you do see a storm and do hear thunder - you need to head for shore depending on the size of your vessel. Small craft less than 25 feet or so should really be worried about weather. These boats for obvious reasons cannot operate in rough weather nor are they equipped to do so. What is a dangerous wave height for 21 foot or less craft? Usually 4-6 feet or higher waves are turbulent for small craft. The larger the craft is the smoother the operation in turbulent waters. However, operating in turbulent water or dangerous weather should be avoided when possible.

RESOURCES TO KEEP A EYE ON THE WEATHER USING TECHNOLOGY!

If you have a cell phone with internet access, satellite internet, TV, or other means on board your craft you may also monitor Weather Radar. This is a great tool to better pinpoint danger areas and navigate around storms. A word of caution - radar is a technology that is complex and requires an experienced scientist to fully interpret or understand. With that being said, you can get a general idea of conditions by observing a recent radar image for your area. Let's take a look at radar images covering intracoastal waters of eastern Florida.

Radar coverage is very good as most pleasure craft operate close to the shore or inland. Doppler weather radar can show intensity of storms, rainfall, and wind estimates. This is a great tool to use if you are managing any outdoor event. Remember that even in a non-severe storm lightning is dangerous and deadly. In addition, flooding is a killer! Other dangerous include high winds, tornadoes, water spouts, and hail.

The radar image above shows average small thunderstorms offshore on the Atlantic Ocean. Color scales used on this radar go from green to red. Green is light precipitation and red is heavy precipitation. If you are boating, you should also consider light precipitation as it can grow or become stronger quickly. Try to avoid these areas not just to stay dry, but to stay safe. Small storms can grow or be underestimated. Do not get yourself caught because you didn't consider sudden intensification, a change in direction, or growth in size.

Sometimes other storms can generate atmospheric frontal features that will cause the development of additional storms. Just because you see one storm doesn't mean others can't or will not form. Consider that if one thunderstorm exists, the environment can support another (for general purposes). Here (left) is an example of storms being generated from outflow of another storm. Think of it as one storm feeding another or sparking more storm development. Radar anomalies can also occur and you must consider time of day, year, location, and other atmospheric variables which can make radar behave differently (for more advanced users).

Give yourself enough time to navigate to safety. This includes having a cone of danger in your mind which should be 25 miles circumference if you are close to shore (within 3 miles). Monitor storm movement and weather forecast information. Remember storms can change direction and strength! The images above show good examples of danger cones and return times. Never wait until the last minute! Navigate to safety as soon as you see dangerous weather approaching or hear of a warning affecting your area via NOAA Weather Radio. Special note: some marine warnings are broadcasted from Coast Guard stations on vhf marine radio frequencies.

COUGHT IN THE STORM

If you are unfortunate and caught either in the storm or immediately in the area of the storm, dawn your PFD. Have everyone on your vessel put their life vests on and if time rain covers. Head for shore and a safe structure as soon as possible. Stay below deck if possible. Keep away from metal objects that are not grounded to the boat's protection system. Inform a third party or your contact point of your location and that you are returning to shore. This is a safety measure commonly used to let another party in a safe location where you were and where you are going in case you need them to get help for you.

Continue to remain calm although taking action quickly. Keep your passengers calm. During this period you should also continue to monitor NOAA Weather Radio as storm information is broadcasted 24 hours.

SAFETY

Most accidents can be prevented. If you are planning any boating activity consider the weather conditions ahead of time. If conditions are good and you set out to operate your boat, always continue to monitor the weather condition along with NOAA Weather Radio. Storms can suddenly develop, change direction, or strength with little or no advanced warning. Remember that lightning and high winds pose a threat to safety while you are boating.

Having a plan of action to deal with dangerous weather should be part of your boating/outdoor experience. You should have life vests for everyone on board, a fire extinguisher, first aid kid, flares, and NOAA Weather Radio. Many marine VHF radio manufactures now have the built in NOAA Alert function which will silently monitor the weather broadcast and sound an audible alert tone when a warning is issued. Consider having a marine VHF radio onboard your boat, no matter what the size is!

Boating is a great sport, outdoor activity, and hobby. The experience can be much better if you stay alert, aware, and informed. For more information on Marine Weather Safety see the links below. Thanks again and stay safe while on the water!

© StormSector 2009

NOAA Safe Boating (LINK)

Important terminology discussed here includes the following terms:

Small craft - considered arbitrary although the US Coast Guard defines small craft as boats with total length less than 30 feet or 10 meters. Your author agrees with this, but may more specifically refer to crafts that are less than 21 feet in length. Even at 25-35 feet you should consider small craft advisories.

Marine warning - is issued whenever a severe local storm or strong wind of brief duration is imminent and is not covered by existing warnings or advisories. Remember that being out on water is different than on land and even moderate storms can cause major issues or be life threatening.

Tropical system - a tropical influenced regional storm system which can either be tropical storm strength or all the way to hurricane strength with winds 74mph or greater. Definitely nothing to be boating in at all - no craft should be operating in these conditions. Even during a watch situation (without a warning) consider not even going out as conditions can be rough well outside the main storm center.

PFD(personal flotation device) - These are life saving devices designed to keep you floating and come in three types depending on use, etc. Every boat should have enough life vests "PFD's" for each person to wear (1:1 ratio).

Marine VHF radio - Usually installed on all large ships and most motorized small craft used for communicating with marinas, rescue, etc, operating between 156-174 MHz, considered to be a primary marine communications radio system.

NOAA Weather Radio - special marine warnings along with other land based weather information and warnings as well as forecast information is available 24 hours via government 162 MHz radio broadcasts. Special receivers can also sound an alarm when warnings are detected alerting the user just as a pager would.

Weather Radar - Radio detection and ranging electronic technology which scans the atmosphere and captures moment data such as reflectivity, velocity, etc... This data can be used to better detect severe weather, high winds, tornadoes, large hail, rainfall, and storm motion.

Special frequencies: NOAA Weather Radio:162.400 MHz, 162.425 MHz,162.450 MHz, 162.475 MHz, 162.500 MHz, 162.525 MHz, 162.550 MHz, Coast Guard Marine NAVTEX: 518 kHz, Coast Guard VHF (Channel22A): 157.1 MHz, National Institute of Standards and Technology : 2.5 MHz, 5 MHz, Time and Frequency:10 MHz, WWV and WWVH:15 MHz, 20 MHz.

Compiled by Ben Alonzo/StormSector 2009.

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