Weather Watch

Are old sailor weather proverbs true?

Meteorologists have concluded that there’s truth to the old sailor saying, “Red sky at night, sailor’s delight. Red sky in the morning, sailor’s warning.”
Meteorologists have concluded that there’s truth to the old sailor saying, “Red sky at night, sailor’s delight. Red sky in the morning, sailor’s warning.”

The jet stream/storm track has shifted southward, gained strength and has taken a more direct path across the Pacific toward California. These are all signs that El Niño has started to impact our weather.

Overall, it’s looking stormy with moderate to heavy rain, gale-force southerly winds and high waves along the coastline this week. Long-range models indicate that the unsettled weather pattern could continue through mid-January, if not longer.

With stormy weather bearing down on us, I thought it would be interesting to look at some weather proverbs. Before the latest computer models or satellite images were available, sailors depended upon observations of the ocean and the sky to forecast weather.

I can only imagine what it was like to be in the middle of the vast Pacific Ocean on a vessel without the use of modern weather forecasting tools and instrumentation. The threat of large waves or strong winds would be a constant concern.

Out of necessity, sailors came up with sayings or proverbs such as, “Distant shores loom up nearer before rain because of thinning of the air,” and if the air was humid, “rain is most frequent at the turn of the tide.” Many of these sayings have proven mostly untrue over the years.

However, one saying often proves to be accurate. In the Bible (Matthew 16: 2-3), Jesus said, “When in evening, ye say, it will be fair weather: For the sky is red. And in the morning, it will be foul weather today; for the sky is red and lowering.” Most historians agree that this Bible verse became the weather proverb: “Red sky at night, sailor’s delight. Red sky in the morning, sailor’s warning.”

Meteorologists for years have studied this saying at our latitude along the Central Coast and have concluded this adage is more often true than not.

Here is why: At our latitude, the jet stream often steers areas of high and low pressure from the west toward the east. High pressure usually produces clear weather as the air sinks toward the surface, while low pressure often produces unsettled or stormy weather.

When an area of high pressure is to our west, red sunsets are often produced because of air contaminants such as dust, aerosols, salts and smoke near the Earth’s surface. The sun’s light shines through these particulates, which scatter and greatly diminish the shorter wavelengths that reflect the blues in the visible light spectrum. This leaves behind the longer wavelengths, such as the red hues seen by our eyes.

If a sailor sees a red sunset at sea, it most likely means that the area of high pressure is to the west and moving eastward toward them, indicating clear and dry weather on the way.

On the other hand, if a sailor sees a red sunrise, this could mean an area of high pressure is to the east, with an area of low pressure following close behind. Stormy weather will likely be on the way.

Most readers would agree that today’s forecasters, including myself, are sometimes wrong despite the use of modern weather forecasting tools. With that in mind, weather sayings may have far more value than meets the eye.

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At PG&E, your safety is our first concern. PG&E has been preparing for storms like the ones we may see this week. PG&E urges its customers to be ready for natural disasters. That includes having a family emergency plan and keeping emergency kits for your home, your office and your vehicle. PG&E offers emergency-preparation tips on its website at www.pge.com/en/safety/preparedness/index.page.

John Lindsey’s column is special to The Tribune. He is PG&E’s Diablo Canyon Power Plant meteorologist and media relations representative. Email him at pgeweather@pge.com.

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