ARIZONA, USA — The National Weather Service in Flagstaff tweeted out pictures of a rare cloud formation Tuesday afternoon.
NWS said convective cells formed in Arizona's high-altitude cirrus cloud deck, creating the distinctive cloud pattern.
VERSIÓN EN ESPAÑOL: Raro estampado de nubes en el cielo en el valle
The clouds were the result of elevated atmospheric instability, according to NWS.
Atmospheric instability happens when the air near the ground heats. The air becomes more and more unstable and becomes more likely to rise convectively.
In meteorology, the term convection describes the vertical transport of heat and moisture in the atmosphere, especially by updrafts and downdrafts in an unstable atmosphere.
According to NWS, those conditions allowed for the beautiful display in the afternoon sky.
NWS said the phenomenon is relatively rare.
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How big is Maricopa County?:
Maricopa County is the United States’ 4th largest county in terms of population with 4,485,414 people, according to the 2020 Census.
The county contains around 63% of Arizona’s population and is 9,224 square miles. That makes the county larger than seven U.S. states (Rhode Island, Delaware, Connecticut, Hawaii, New Jersey, Massachusetts and New Hampshire).
One of the largest park systems in the nation is also located in Maricopa County. The county has an estimated 120,000 acres of open space parks that includes hundreds of miles of trails, nature centers and campgrounds.
The county’s seat is located in Phoenix, which is also the state capital and the census-designated 5th most populous city in the United States.
The county was named after the Maricopa, or Piipaash, Native American Tribe.
What is the Valley?:
“The Valley” is what locals call the Phoenix Metropolitan Area. It is considered the largest metropolitan area in the Southwest.
The Valley is made up of various major cities other than Phoenix, including:
- El Mirage
- Litchfield Park
Whether a city is in the “East Valley” or “West Valley” depends on where it is in relation to Phoenix.
The cities of the Valley have a combined population of 4,845,832 people, according to the 2020 United States Census. This makes it the 11th largest metropolitan area in the country right behind the Boston and Atlanta areas.