Snow Loss and Flooding in our Tower
2017-02-26 15:28:38.000 – Adam Gill, Weather Observer/IT Specialist
Over the last 4 days we have seen temperatures above freezing with only a handful of hours below freezing. This has unfortunately lead to tons of snow melt up here. Much of the snow pack that we had around the summit is now gone! As someone who really likes the snow, it was terrible to see all the snow melt so quickly. One thing that always surprises me up here is how fast the snow will melt when we have one of these thaws. The reason for this is because of all the warm fog the past few days. With this set up, we had very moist air flowing over the summit developing into fog that was well above freezing. When we are in the fog and above freezing, moisture will condense to the snow because it is below the dew point temperature, similar to the condensation you get on a cold drink in the summer. When water condenses to the snow, it releases quite a bit of latent heat as it goes through the phase change accelerating the snow melt. In Mike’s previous comment, he stated how we went from 30 inches of snow to 15, but now we are down to 10!
This rapid snow melt has led to some problems with keeping water out. With south and south east winds, the drizzle and rain was blowing right at our tower and deck door. This caused a lot of water to make its way in, and with the above freezing temperatures, the frost on the walls and windows were melting and adding to the mess! This is a common issue that we have so there is a gutter system set up to be able to capture much of the water. There are a few areas though where the water was dripping everywhere so lots of buckets were used!
One major issue that came up was at the bottom of the tower. We have a door from an old destroyer there that is supposed to keep water out during melting events. The reason we have water issues at this location is because it is an area that the snow drifts so the drift can act like a dam and hold water against the building rather than letting it flow off of the mountain. This year that drift was near 20 feet so it was able to hold back quite a bit of water. The seal around the door is getting really old so there was a steady trickle of water coming in. We do have heat tape that runs across the ground outside to melt a tunnel at the base of the drift to drain the water but it didn’t work right a way and took a few hours to melt a drainage hole.
In the mean time we had to have a sump pump going in the base of the tower to keep the water from flowing into the living quarters. Luckily temperatures have fallen back below freezing so all the water issues have ended for now. Looking ahead we will have a brief stint back into winter but a large mid-west storm could pump warm moist air back into the region for Wednesday into Thursday.
Adam Gill, Weather Observer/IT Specialist