03 Sep 2018

Electricity North West weather watch- September

In general, the first five days of August continued where July left off, with a lot of dry, settled and warm weather, as high pressure continued to linger across much of England and Wales.

Let’s find out if the sunshine will remain from MeteoGroup senior meteorologists Matt Dobson and George Goodfellow.

A look back

A cloudy and damp day on the 6th, brought about by a couple of weak fronts, paved the way for a more unsettled Atlantic airflow to predominate during the rest of August, with frequent areas of low pressure.

The 8th, 9th and 10th all saw an unstable airmass encouraging heavy and thundery showers to develop, with the most frequent showers in the north-west on the 10th. The 11th was warmer and quite humid, although thickening cloud brought widespread rain to the region overnight and early on the 12th.

Although frequent heavy showers developed to the east of the Pennines on the 13th, much of the North West region remained dry. Around the middle of the month, a couple of low pressure areas moved east between Iceland and Scotland, the most active of which brought a good deal of rain to the region during the 15th, with scattered showers breaking out the following day. There was further persistent rain overnight from the 18th-19th, as an active low pressure area moved across southern Scotland.

Until the 22nd, high pressure moved across most of England and Wales, keeping it settled for a time. The final nine days of August saw intermittent areas of low pressure followed by short-lived high pressure areas. A set of particularly active fronts moved across the region on the 26th, when widespread persistent rain developed early in the day. The month ended on a dry note, with a ridge of high pressure providing settled weather.

A look ahead

August provided quite a contrast to the early summer months of June and July, giving much cooler, wetter weather. However, there are strong indications that much of September will see a return to dry, settled conditions, dominated by high pressure. In fact, our latest research suggests that a cold end to the winter (as in 2018) is nearly always followed by a drier than average September, of which 2006 and 2013 are the most recent examples.

Some warm, ‘summer-like’ days are expected, especially early on in the month, when the orientation of high pressure may draw up warmer air from the east or south-east at times. However, the nights and mornings are likely to become increasingly chilly, as the daylight rapidly dwindles at this time of the year. Towards the middle of the month, there is unusually good agreement that high pressure will continue to dominate, despite incursions of tropical systems from the Atlantic often lowering forecast confidence during the early Autumn.

During the final ten days of September, there are indications that a more significant pattern change will develop, with high pressure moving to the east of the UK, opening the door to Atlantic weather systems moving in from the west, which look like giving more widespread wet and breezy days. Temperatures will likely fall a little below average, to give a much more autumnal feel to the weather.