After a week of no precipitation of any normal sort, you’d be forgiven for thinking that water levels in the borehole would have stopped rising, or even fallen, but you’d be mistaken. Although the rate of rise has been quite slow, it has been steady throughout the week.
The levels have fallen away from the 9-year average line, but remain significantly higher than the last big flood year and the driest Spring in our records. So, what’s been going on and why have the water levels been rising? It’s probably all to do with what is called the triple point of water; the conditions of pressure and temperature where all three states of water (solid, liquid and vapour) can exist at the same time. If you want to know more about that, I suggest you ask Mr Google or a physics graduate! Anyway, what it means is that some of the frost on the ground, at certain times of day, during the week was turning to water and vapour and some of this was going into the ground. At the same time, some of the humid air was turning to solid and more water, some of which was also going into the ground. The triple point is all quite mind-bending to me. It’s also behind why cold weather in England, at around freezing point, often feels far colder than real Arctic climates.
Despite the river, freezing, thawing and re-freezing several times over the week, the levels in the river have continued to rise. That said, none of the springs to the north of Spring Lane has produced sufficient water to fill the river by the bridge in Church Street; if they are flowing at all.
The “drought” this morning was broken at around 08:00 by rain that first fell as micro-hail. Hitting the frozen ground, it cooled it still further and instantly turned to black ice. That might have happened on the A303 as well, as there was a stream of emergency vehicles heading west soon afterwards and at 09:15, Church Street was still like glass. We are anticipating much more rain throughout the day with temperatures rising steadily, even through the night. The early part of next week can be expectedd to bring more rain and windy weather.
The mild and wet conditions are likely to persist all through the Christmas period, getting marginally colder for the New Year, before getting warmer and more unsettled. After that, the picture gets more confused, with different models suggesting very different weather patterns. There does seem to be the potential for some very cold weather towards the middle of January though.