Thursday 28 March 2019

Snow Patch Predictions 2019

The North Face of Ben Nevis on the 1st of March. Not very wintry!
Although the exact date will vary from year to year, it is around this time of year that the volume of snow in the higher Scottish coires reaches it's maximum. Snow cover is something I am interested in and have written about previously on my blog. However, during the past couple of years I have been away in the Antarctic for long stretches of time, and thus have not been a bit less focused on Scottish snow. This year I plan to remain in Scotland for the summer, and am taking a bit more of an interest in Scottish snow.
This winter has been an unusual one to say the least. There were periods in late February when there was very little snow on the hills. In fact conditions felt more like the early summer than the middle of winter.  In early March winter returned with a vengeance with loads of snow falling over about a ten day period. However, was that enough to catch up with other winters in terms of snow volume? Below is a picture of Coire an Lochan of Aonach Mor taken a few days ago. 

Coire an Lochan. 23rd of March 2019. 
How well the snow patches last into the summer, and whether they survive into the following winter depends a number of factors. However, I would say that snow depth at this time of year is the strongest predictor of how much snow if any will survive through to the following winter. This is particularly the case when the snow depth is either unusually large or small.

Below are pictures of the same place for every year going back to 2008. All the photos were taken late March or early April. I would say that this year has the least snow. Other poor years are 2017 and the years 2010-2012.

In 2017 all the snow melted in Scotland. In the summers of 2010 to 2012 snow patches did survive through the summer, but in general they were very small by the time that lasting snows of the following winter came. A slightly warmer summer, or if the lasting snow had fallen a week or so later, then the patches may not have made it.

Despite the fact that it is a low now year, there is actually a fair mass of snow there see a post I wrote for the SAIS Lochaber blog;
However, I think it would take a combination of an unusually cold snowy Spring followed by a cool dry summer for any snowpatches to survive through to next winter. I don't think it is likely they will survive this year, but am hoping to be proved wrong about that.
2018- One snowpatch survived the to the following winter.
2017-No snow survived to the following winter.
2016-Seven snowpatches survived to the following winter.
2015-A good year!.Seventy four snowpatches survived to the following winter.
2014-Also a good year. Twenty one patches survived to the following winter. 

2013-Six snowpatches survived to the following winter. 
2012- Six snowpatches survived to the following winter. 
2011-Two (tiny) snowpatches survived to the following winter.
2010 Six snowpatches just survived to the following winter. All were very small. 
2009 Six snowpatches survived to the following winter.
2008-Twelve snowpatches survived to the following winter.