All six counties in Northern Ireland have been issued with a weather warning ahead of the expected arrival of thunderstorms on Tuesday. The UK Met Office has issued a yellow thunderstorm alert for Antrim, Armagh, Derry, Down, Fermanagh and Tyrone, which came into effect at 11am on Tuesday and will remain in place until 5pm. The forecaster said: "Heavy rain and a few thunderstorms may cause disruption in a few places, especially to travel, with isolated surface water flooding," reports Belfast Live. "Heavy rain will affect parts of Northern Ireland followed by some heavy showers and a few thunderstorms breaking out later this morning and into the afternoon, before clearing eastwards by evening. "In some places these could produce 15-20 mm of rain in less than an hour, with a few spots seeing 30-40 mm in a few hours. Isolated hail and lightning strikes will be additional hazards." With golf fans descending upon Portrush for the return of The Open Championship, which gets underway on Thursday, the Met Office has warned there is a chance driving conditions will be affected by spray, standing water and/or hail, leading to longer journey times by car and bus. Other potential impacts from thunderstorms include some flooding of homes and businesses, short-term loss of power and other services, delays to train services and damage to buildings and structures from lightning strikes. In better news, Met Éireann has indicated that a spell of high pressure looks likely to improve conditions in Ireland next week as drier weather returns and temperatures remain above average. While there is a fair amount of uncertainty regarding next week, Met Eireann has suggested that "high pressure looks set to build in across Ireland at times which will bring a more mixed weather outlook with good dry periods forecast". "Air temperatures are forecast to stay above normal across the country and much of northwest Europe also. Rainfall amounts will be down on the preceding week with forecast rainfall totals of around or slightly below the climatological average for late July." It will be generally cloudy and wet on Tuesday as the national forecaster warns of the possibility of rain and a few thundery downpours. Thankfully, it will become drier and brighter into the afternoon as more pleasant conditions spread eastwards but there will be a few showers mixed in. It will be a cooler day, however, with temperatures struggling to get above 20C in moderate to fresh westerly breezes. Tonight will be drier with plenty of clear spells but mist and fog is set to develop, particularly in Connacht and western parts of Ulster. Outbreaks of rain will spread across the southwest in the morning as temperatures range between 9C and 12C overnight. Subscribe to our newsletter for the latest news from the Irish Mirror direct to your inbox: Sign up here.