Wednesday 11th March
The intermittent broken sunshine on Wednesday transformed the day, compared to previous days. The maximum temperature of 11.3C at 12.24 was almost identical to the peak on Monday, being 0.5C above average, however, when the sun did shine it raised the UV level to a peak of 1.9, which is within touching distance of being classed as a ‘Moderate’ strength, it was also equal strongest with that logged on the 2nd. Another indicator of the strengthening sunshine was a peak solar radiation of 631W/m2, the highest since the 5th October. The peak on Saturday, under the thick cloud, was only 151W/m2.

There was welcome sunshine shortly after sunrise on Wednesday, sadly it disappeared around 08.45. Overnight two weather fronts had passed over our area that saw the barometric pressure drop to 1004.5mb at 02.02, the lowest pressure since 19th February. The rain began just after 21.00 Tuesday even and ceased just after 04.00 early Wednesday, amounting to 5.2mm, that made it the wettest day in March. The wind will increase in speed towards midday and into the early afternoon as the weather fronts traverse eastwards.

A stormy day will arrive on Thursday with strong winds from early morning until late evening, when rain will arrive, that is likely to be heavy and continue well after midnight. Friday will be a damp day with light showers, also much cooler with the maximum below average and the following night very cool, almost down to freezing as the air stream will have originated near Iceland and Greenland thanks due to a deep depression that tomorrow will head in the direction.

I attach part an interesting article on meteorology, just published.

We have a number of equations and I think all of us meteorologists have horror stories about the different math classes we took in college to try to learn them.

To use meteorological mathematics, you have to figure out the physics and dynamics of the atmosphere, which is not easy.

This means we have to predict the movements of a liquid because the atmosphere is a liquid. Then, of course, that liquid creates other liquid, meaning rainfall, snowfall and that sort of thing, which comes down to physics.

For those equations to work, you need every sort of weather data that you can think of: temperature, humidity, wind speed, how much moisture there is in the air and all of that information at different levels, too, because the layers of the atmosphere don’t act independently of each other.

To gather that data, you need weather balloons and observation stations and satellites gathering data at different altitudes.

Each one of those layers can act a little bit differently. One layer could be 30 degrees, the next one up is 32 degrees, and the wind speed might be a little stronger up aloft and a little different direction. You may have heard a meteorologist say that the European model is a little better than the Global Forecast System. Part of that is because the Euro has more layers.

Each of the variables is going to be used in the equations. We have to get all of the data as correct as possible. There’s a saying in models: “If you put junk in, you’ll get junk out.”