Saturday, January 15, 2011
Graupel NOT hail
The past few days we've gotten well over a foot and a half of new snow. All of the snow has been due the 'ocean effect' when moist air off of the Gulf of Alaska reaches land. Anchorage, Homer and places north have not gotten any of this snow and there is a huge mass of cold air in place over the interior. If you've been observant you will have noticed that the snow squalls have been proceeded by a hail of snow pellets. I would like to point out that these pellets are GRAUPEL and not HAIL. Everybody I have been talking to has been calling it hail, and I even heard the announcer on KMXT call it hail. So it is time to set the record straight.
Hail is associated with thunderstorms, and is created when strong updrafts take water up to where it is freezing. The water freezes and often goes up and down in the air column creating multiple layers of ice on what become the hail stones. Graupel is usually associated with maritime climates and is created when a snowflake falls through super cooled water droplets. The snowflake acts as a nucleus and the water droplets freeze onto it as rime. Graupel is also known as 'snow pellets', and is basically little balls of snow. Hail is balls of ice.
So there you have it. Enjoy the graupel and I hope it keeps on falling. The pictures are of 'graupel clouds' above Buskin Lake yesterday. Patrick