Arizona’s chilly conditions could lead to a combination of rain, snow, hail, and graupel.
Arizona is often associated with its arid landscapes rather than its wet weather, yet even in this dry region, various forms of precipitation can occur — particularly in the winter months.
Arizona winters can deliver a variety of weather conditions, ranging from rain to snow and even freezing rain.
A genuine blend of winter weather — familiar to those from colder regions — is uncommon in the Phoenix area because of its milder temperatures and lower altitude, yet it has occurred.
Since records started in 1896, central Phoenix has experienced measurable snowfall on only a few occasions. In elevated regions near the metro area, occurrences of snow, hail, and sleet are somewhat more common.
In Flagstaff and similar high-altitude regions, winter precipitation plays a crucial role in Arizona’s climate and its water resources.
“You can get sleet, freezing rain, snow and rain all from the same storm system,” said Erinanne Saffell, Arizona’s state climatologist. “That’s that wintery mix possibility, depending on what happens to those snowflakes. It depends on what’s happening with the temperature closer to the ground.”
First and foremost, winter brings rain. When temperatures hit 32 degrees and moisture is present in the air, water vapor transforms into tiny ice crystals, resulting in snowfall. However, even if snow develops, it might not make it to the surface.
When ice crystals within a cloud cluster together, they form snowflakes that grow heavy enough to fall to the earth. When temperatures hover at or dip below freezing during snowfall, the precipitation will persist as snow.
“But as that snow is dropping from the cloud, it can land into other kinds of conditions,” Saffell said.
When snow reaches a warmer layer of the atmosphere, it will melt and transform into rain. When precipitation encounters a surface that is below freezing, it will solidify upon contact, resulting in icy conditions.
When a snowflake dissolves in the atmosphere, it cannot revert to its original form until it ascends back to the clouds as vapor. It has the ability to refreeze, yet it won’t create a new snowflake.
