SPOKANE, Wash. — In March, Spokane's weather can be a bit of a wild card. But it's not often that we get such an extreme contract of weather within the frame of one afternoon.
Spokane got two thunderstorms during the day on March 22. The first hitting the South Hill around 1pm and the second hitting downtown just after 5pm.
While March thunderstorms aren't the most rare thing for Spokane, it's the intensity of the graupel and hail mix we saw in both set of storms.
When we move into the warmer months, it's easier to get more energy and convection in the atmosphere to produce strong downbursts or thunderstorms. It's a good sign that Spring has arrived. But at the same time, we're still exiting winter and often times the temperatures can be cold enough to support icy precipitation types.
What is Graupel? Graupel is like soft hail or ice pellets like sleet, but are formed differently. Snowflakes falling from the cloud that collect super-cooled water droplets create the small ice pellets. The texture is similar to Dippin' Dots.
Hail, on the other hand, is when ice crystals in the atmosphere are suspended in the cloud by the upwards winds, known as the updraft. The ice crystals collect more and more water vapor to grow in size until the hail stones created are too heavy for the updraft to sustain.
During the summer time, hail stones that fall tend to melt to a degree before hitting the ground, since the atmosphere is plenty warm. But on a cool March day, the freezing levels are already close to the ground and the hail doesn't have much, if any time, to melt. So it's easier for those small hail stones to hit the ground without melting any.
How can you tell the difference? Graupel is far more fragile. If you hold graupel in your hand, it tends to melt in no time. But hail is more rigid. It's takes longer to melt and it's very difficult to crush if you try to squeeze a hail stone.
Spokane got a mixture of graupel and hail in both sets of storms. Additionally, others across town were reporting rain and snow. And between the storms, it was pretty sunny in Spokane.
The fight between the energetic Spring weather and the colder Winter weather seems to be playing out in the form of these storms. But the deeper we get into the season, the less likely it is to see any icy precipitation, save for some hail in the strongest of thunderstorms the Inland Northwest has to offer.
