CU Boulder researchers have created a map of the Northern Hemisphere showing how location and humidity can affect precipitation, illustrating wide variability in how and why different areas receive snow or rain.
32 degrees Fahrenheit is commonly considered to be the air temperature threshold for rain versus snow, thus informing meteorological forecasting and climate simulations. The new findings, however, show that coastal areas have a cooler threshold for rain, meaning that even temperatures below freezing might not produce snow. Inland and mountainous areas, meanwhile, are likelier to see flurries even when temperatures are several degrees above freezing.
“In Denver, Colorado, it might be 40 degrees and snowing. But in Charleston, South Carolina, it could be 28 degrees and raining,” said Noah Molotch, Director of the Center for Water Earth Science & Technology (CWEST) at CU Boulder and a co-author of the study. “This study shows these fine-grain differences on a hemisphere-level scale for the first time.”
The research, which compiled nearly 18 million precipitation observations spanning over 100 countries and four continents across the Northern Hemisphere, was published today in the journal Nature Communications.
Read more at University of Colorado at Boulder
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