It’s springtime late winter in Minnesota. The time of year when the weather gods enjoy torturing toying with Minnesotans. The weather turns warm and sunny for a few days, melting patches of the snow cover – then temperatures suddenly dip below zero and drifts of powder snow accumulate again.
Yesterday it was sunny and high temperatures were in the 40’s. Today — we have thundersnow.
Thundersnow is an unusual and, as yet, poorly understood phenomenon. It is defined as a heavy snowstorm with thunder and lightning. Rare winter thunderstorms produce large amounts of snow. Thundersnow happens most frequently in March, and only a few such storms are reported in the US each year.
According to a report on today’s KARE11News there is an old saying that:
If it’s snowing and you hear 1 clap of thunder stop shoveling for a moment and take a breath because you are going to get 3″ of snow in the next hour.
If it’s snowing and you hear 2 claps of thunder stop shoveling and go inside and have a meal because you are going to get 6″ of snow in the next few hours.
If it’s snowing and you hear 3 claps of thunder stop shoveling then go inside eat a meal, watch tv, have another snack and go to bed because you are going to get +12″ of snow in the next 6 hours.
So, I’m sitting here by the fire with a cup of chai in my hand, a big pot of chili on the stove and a couple of good books at my side because it’s gone well beyond three claps of thunder here in the last half hour — and it’s much too early to go to bed.
Thundersnow is typically created by strong updrafts within the cold sector of an extratropical cyclone in autumn or spring when ground temperatures are near or below freezing. One of the strangest things about thundersnow is the way that the heavy falling snow dampens the sound of the thunder. It’s fascinating to listen to. Muffled claps of thunder interspersed with an occaisional clap of loud thunder – immediately following the glow of lightening. It’s so quiet. Long pregnant pauses between the peals of thunder create an odd sense of expectation. Invisible lightening bolts in a blizzard sky disorient me. Spring seems impossibly far away.
To make this post at least somewhat dog-related I’ll add that neither of my dogs is afraid of thunder. And, I think that observing a thunderphobic dog’s reaction to a thundersnow storm would be a good test to see if his fear was was created more by the sound of the thunder or the static electricity and barometric pressure changes associated with such storms.