Beyond The Forecast: Why the sky changes colors at sunrise and sunset

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Happy Tuesday! It’s the start of a shortened workweek for many of you and if you were up early this morning, you were rewarded with a beautiful sunrise!

Viewer Jerry Carr sent us a photo of his view of the rising sun, featured at the beginning of this newsletter. The gorgeous scene got me thinking: why does the sky change color when the sun is rising and setting?

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When the sun is high in the sky during the midday and afternoon, we see blue overhead. This is explained by the phenomenon known as Rayleigh scattering.

(Copyright 2021 by WSLS 10 - All rights reserved.)

When the sun is rising or setting, its light has more atmosphere to pass through. The light is scattered at longer wavelengths, thus we see warm colors like red or purple or pink.

Cloud cover obviously plays a factor in whether we get to enjoy the nice color.

If you want the opportunity to snap an Instagram-worthy photo of the rising or setting sun, you should root for cirrus clouds to be in the forecast. The ice particles within these wispy, high-level clouds scatter more light, enhancing the color in the morning or night sky.

Thicker clouds like cumulus or stratus often hinder our ability to see the sunrise or sunset.

(Copyright 2021 by WSLS 10 - All rights reserved.)

Your Local Weather Authority will always let you know if we expect a nice show at sunrise or sunset and we love showing your photos! A good resource to bookmark if you’re hunting for the colors? SunsetWx.com, which features daily sunrise and sunset forecasts generated from model data.

Speaking of sunrises, you may have noticed light in the sky slightly earlier in the morning lately. We reached our latest sunrise times in early January and sunrises are now getting earlier through mid-March.

We’ll briefly “spring forward” and get later sunrises again after March 14 (the start of Daylight Saving Time), with our earliest sunrises of the year eventually coming in June. That’s also when we get our latest sunsets of the year.

(Copyright 2021 by WSLS 10 - All rights reserved.)

Switching gears to the forecast, we’re stuck in a persistent pattern of cool breezes and mountain snow through the middle of the week. Meteorologist Chris Michaels is tracking when we could see some changes in our daily forecast article.

You can always get specific forecast details for your zone, whether it’s the Roanoke Valley, Southside, the Highlands or elsewhere around Southwest and Central Virginia, anytime at WSLS.com/weather. Know your zone!

In case you missed it, we’re posting great weather and science content on WSLS.com. Here are a few links from the past week to check out:

If you prefer your weather information delivered by social media, you can follow Your Local Weather Authority on Facebook and Twitter.

-- Justin McKee


About the Author:

Justin McKee presents the weather forecast on 10 News Saturday and Sunday mornings from 6 to 8 a.m. He also fills in for other meteorologists during the week.