Warm start to week to make way for wetter and windier conditions
A stronger jet stream will bring a distinctly autumnal look to our weather this week, but is there a September heatwave on the horizon later this month?
This week's weather patterns are expected to remain changeable, with intermittent spells of wet and windy conditions. Initially, Monday will see a brief warmth and sunshine before a drop in temperature toward the more typical September weather. The jet stream, a high-altitude fast-moving air current, will strengthen, potentially leading to low-pressure systems and minor disruptions towards the following weekend.
By week's end, higher pressure is anticipated to return, but the likelihood of a late-September heatwave remains uncertain.
The jet stream's position, speed, and shape dictate the weather experienced. At the start of the week, it will be fairly weak, looping to the north of the UK, enabling a high-pressure system and a warm south-westerly airflow. As the week progresses, the jet stream will shift to a more southerly path, becoming faster and straighter, which will result in lower pressure, rain, and brisk winds, as well as cooler temperatures.
Monday will be the warmest day, with southerly winds bringing in air from warmer regions. Many areas will remain cloudy, with coastal and hill regions in the west seeing some rain. Despite the clouds, temperatures will be quite comfortable, with highs of over 20C in numerous locations. In central and southern England, it could reach a high of 26C. By Thursday, winds will shift more westerly or north-westerly, bringing a cooler air mass.
High-pressure systems may exert more influence on the weather during September's final week, potentially leading to extended dry spells and the possibility of returning above-average daytime temperatures. However, the extent of the temperature rise will depend on the high pressure's positioning relative to the UK. While long-range forecasts are uncertain, there's no indication of a heatwave this autumn.
As autumn progresses, the nights will become longer, and high pressure overhead could lead to chilly mornings. For real-time temperature updates, consult the BBC Weather online and app.
Written by urgent.news from BBC News's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
