Would you believe that the moon can shine through ice crystals high above the earth's surface to warn you of rain tomorrow? Or that bolts of lightning sighted to the northwest will be on top of you in a matter of minutes!

Weather lore has been passed down from sailor to sailor for thousands of years. But if you're anything like me, you'd like to know the simple science behind the sayings. Here are five well proven tips that you can use for cruising or day-sailing:

Take a bearing when you first sight lightning on the horizon. Lightning between the west and north will pass nearby.

"Lightning from the west or northwest will reach you; from the south or southeast will pass..."

Cumulonimbus monster clouds carry high impact charges inside.

These self-contained weather-bombs move from west to east, giving off hot charges of lightning as they go.

If you see bolts of lightning between west and north, it will pass over you or nearby.

Make preparations now to get your sailing crew ready for squally weather.

Lightning between south and east has passed you. It's no longer a danger to you or your sailing crew.

Use a reddish hue at sunrise or sunset to foretell of weather to come. Weather fronts move in a general west to east direction. A red sky to the west at sunset tells you that clear, dry weather will be over you soon.

"Red sky in the morning is a sailor's sure warning; red sky at night, is the sailors delight..."

Count on this to be accurate about 70% of the time.

Weather moves from west to east. Think of the sun, air (atmosphere), and your small cruising boat all in a line--in that order. When the sun shines through dry air, it can appear reddish.

If you see this at sunrise, it means good weather has already passed your location. Wet, blustery weather lies to the west, and will be over your position soon.

On the other hand, a red sky to the west at sunset means that fine weather is on the way. Tomorrow will bring dry air along with a fine sailing breeze!

"The hollow winds begin to blow..."

Use this to foretell the onset of rain or fog. Have you ever noticed how sound changes from one place to another? For example, if you clap your hands together outside, the sound will be flat.

But if you clap your hands together inside a building, the sound will be louder and echo. The ceiling and walls trap the sound waves inside this smaller, enclosed area.

When clouds thicken, they get heavier and lower to form a "ceiling" near the earth's surface. Sound volume increases and takes on a hollow tone. That's one reason sounds are so intense in fog. Like a cloak, this heavy, moisture-laden cloud we call fog hovers right next to the earth's surface.

"The moon in halos hid her head..."

When warm moist air flows in beneath cooler air, it forces high level cirrus clouds aloft. These wispy clouds are made of ice crystals and hang out in the atmosphere at altitudes of over 25,000 feet!

When the moon shines through cirrus clouds, you'll see a halo form around the edge. Prepare for the long, steady rain of a warm front.

"Rainbow to windward, rain ahead; rainbow to leeward, rains end..."

Rainbows shine only over air saturated with moisture. Storm clouds move with the winds, so if you see a rainbow upwind, the storm will soon be overhead. On the other hand, a rainbow downwind tells you that the rain will end soon, followed by clearing skies.

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These five sailing weather tips are just a handful of the many weather sayings useful to sailors worldwide. Use them to increase your sailing safety--wherever in the world you choose to cruise.

"Written so clearly that navigation and seamanship will be comprehensible to anyone."
-- Dave and Jaja Martin, circumnavigators, authors,
and stars of the documentary "Ice Blink"

"It should be read by anyone contemplating
coastal cruising or blue water voyages."
-- Ted Brewer, world famous yacht designer

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