Impacts and probabilities of tomorrow’s snow
Low Zehra has been a bit of a disappointment this week, and has never really engaged with the jet and intensify as much as it was forecast to do earlier this week by our muddle of models. I was fairly convinced this was going to be storm Ellen, but it’s seen as being so innocuous by the UKMO now that they’ve even dropped the yellow warning of strong winds for it. They do have in place a yellow warning for snow for Scotland, and another for rain and snow for northern England and Northern Ireland. I don’t think I’ve ever seen a combined warning for rain and snow but I suppose it makes sense.
The snow warning for Scotland still feels slightly half hearted to me and just an exercise in covering all their bases. They have upped the likelihood of it happening to level two, but the impact remains at level three, this despite them saying that snow could fall to “low levels during the morning rush hour across the central belt”. I would have thought that the impacts of this happening across Glasgow, Edinburgh and along the M80 in the rush hour may have merited a level four impact and an amber warning. Don’t forget the impact has got nothing to do with the probability of this happening in the impact matrix which they love so much.
Now that we are less than 18 hours from the possibility of this happening, surely their mesoscale model, which they run every hour, has now come up with a definitive answer to how much snow will fall across the central belt? Perhaps it has, and they either don’t believe the snow it’s forecasting will happen, or conversely they don’t believe the rain it’s forecasting won’t fall as snow? It’s impossible to say of course because as usual the great Oz never reveals his sources.