UK Weather: Amber heat-health alert for the south and yellow thunderstorm alert for the northA low-pressure system moving through Scotland brings heavy rainfall to the northern UK, which can be heavy at times, with a high risk of thunderstorms. Yellow thunderstorm warnings are issued for Northern Ireland and Scotland. The showers associated with the low-pressure system are expected to become heavy and significantly thundery across Northern Ireland today. While the northern UK have thunderstorm alerts, the southern areas are under heat-health risks this week. The north-south split in weather is likely continuing across the UK on Wednesday, with unsettled rainy weather in the north and widely sunny and warm weather in the south.