It is snowing in central Missouri this morning and the snow will mix with rain throughout the day; up to three inches of accumulation is forecast. If I was back on our Littleton, Colorado, farm, I would expect April snow but not here in Missouri.
A broad atmospheric trough is responsible for the invasion of cold air, dipping across the U.S. from the Front Range to the Ohio River Valley. Low pressure, having formed along the cold front, is sweeping warm, moist air up from the Gulf of Mexico and over the cold air behind the front. While the snow is surely unwelcome in late April, the hard freeze tonight will do more damage to plants and threaten the welfare of migrant songbirds that feed primarily on insects.
No doubt, climate change deniers will point to this outbreak of wintry April weather as evidence that global warming is a liberal delusion. But the loss of snow and ice cover in the Arctic will have dramatic effects on atmospheric patterns that we have come to expect; the severity of storms, floods, droughts, wildfires and, yes, cold weather outbreaks, will likely increase across our planet.
