More clouds, cooler Wednesday; explaining Tuesday's wild sky colors

Isolated showers southwest

WED highs 9am
Forecast high temperatures Wednesday
NOAA via pivotal weather

Expect more clouds than sun on Wednesday with cooler temperatures. Southwestern Minnesota could see an isolated shower. A few thunderstorms are possible overnight into Thursday.

Cooler, more clouds on Wednesday

With thunderstorms all around Minnesota, we’ll have quite a few clouds Wednesday. Expect a mix of clouds and sunshine but there will be more cloud cover than blue sky. An area of high pressure north of Lake Superior will continue to push in air from the northeast, making for a cooler day.

sat high
An area of high pressure is keeping winds from the northeast
College of DuPage

We are sitting north of the main heat dome. Disturbances and thunderstorms occasionally ride up and around the upper-level ridge, giving us some isolated thunder chances.

nat sat
Clouds and disturbances are riding the northern edge of an upper-level ridge
College of DuPage

Southwestern Minnesota could see an isolated shower or two Wednesday. Isolated thunder is also possible overnight Wednesday night across the southern half of Minnesota.

24 hr QPF
Forecast precipitation through 7 a.m. Thursday
National Oceanic and Atmospheric Administration, via Pivotal Weather

The next more significant chances come Saturday night and Sunday nights.

Yellow and orange skies Tuesday evening

Did you see the yellow and orange sky Tuesday evening? It was hard to miss and spurred many questions.

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sunset
Orange sky Tuesday evening
Kip Sundgaard

The reason for the set up had to do with the setting sun and the backside of the derecho that brought severe weather to our south Tuesday afternoon and evening.

During the middle of the day the sky looks blue to us as the path of the midday sun to our eyes is shorter, allowing blue light to be scattered.

vis spectrum
The visible light spectrum and wavelength
National Oceanic and Atmospheric Administration

The longer the path the light has to travel, the more scattering occurs until finally we see just orange or red. This is why sunsets and sunrises are typically orange or red (or with smoke-filled skies scattering even more light like last summer).

NOAA clouds colors
The different colors of clouds at sunset
NOAA

With the core of the storms to our southeast, we had a thick shield of high clouds still overhead at sunset. The setting sunlight reflected off these high clouds. This is why the sky was initially greenish yellow, then yellow, then orange (see the light spectrum chart above).