Oak before Ash?
Most of us have heard odd bits of weather lore; I suppose the most well known is probably 'red sky at night, shepherd's delight. Red sky in the morning, shepherd's warning'. This is trotted out pretty frequently, but I had no idea it first appears in the Bible (Matthew XVI: 2-3 if you'd care to look it up). In other parts of the world, it's sailors and not shepherds who feature, hardly surprising as both farmers and sailors have relied on these old sayings for centuries.
They, unlike most of us, are heavily reliant on the weather. These days modern weather forecasting (despite our criticisms) is pretty accurate - at least over the coming 5 days. Decided whether to go to sea, or cut the grass to make hay, is a much more certain process now, than back in the day.
But are these old sayings accurate? Fair to say, they wouldn't have persisted if their wasn't some grain of truth carried within. Red skies are caused when dust and other small particles are suspended in the atmosphere by high pressure (the particles scatter blue light, making way for the red). A red sky at sunset means there is high pressure out to the west, which for us in Europe normally means fine weather. A red sky in the morning however, means the high pressure has already moved east and is likely to be followed by an Atlantic depression.
I did a fair bit of sailing when I was younger and life at sea abounds with weather lore. One I remember - for no apparent reason - 'Mackerel skies and mares' tails, make tall ships carry low sails'. Pick you way through that! So - mackerel skies (known as sheep clouds in France - 'nuages moutonneux') are cirrocumulus or altocumulus clouds, which indicate moisture at altitudes around 18,000-30,000 feet (6,000-10,000 metres). Mares' tails, meanwhile, are long, threadlike cirrus clouds, often stretched by strong high-level winds. Both clues suggest an impending storm, typically 6-8 hours away, so wise captains will furl the topsails at the tops of the masts and the ship is limited to carrying just the lowermost sails.
So what prompted this short look at weather lore? I was standing at the kitchen sink, doing the washing up and gazing out of the window (as one does). Blocking my view of the field over the lane are two trees, growing next to each other - an ash and an oak.
Ash before oak, we're in for a soak
Confusingly, I have also heard the direct opposite: -
Ash after oak, we're in for a soak
Oak after ash, just a splash
Oak is temperature sensitive, the leaves triggered to grow by a warm spring. The ash on the other hand responds to increasing daylight hours. Ash, historically, has usually been the first to leaf, but our recent warmer springs have reversed the trend, with ash beating oak only a half a dozen times in the last 50 years (BBC Nature). These two were pretty much neck and neck this year.
Neither version of the saying would seem to hold much water (did you see what I did there?) which is probably just as well if this old Dorset saying is anything to go by: -
If oak and ash leaves show together
Us may fear some awful weather.
This be a sight but seldom seen
That could remind we, what has been.
(Some great Dorset grammar there - Thomas Hardy would be proud!)
The next thing to worry about is whether to cast a clout before may be out!