Ernesto, which formed in the mid-Atlantic, is descibed as a post-tropical cyclone – a weather pattern which can bring property-threatening 40mph winds and drenching downpours.
Northern England, parts or Ireland and southern Scotland are likely to feel the worst of the heavy storm.
The storm, which was upgraded to a subtropical storm since forming on Tuesday, has been moving north east across the Atlantic Ocean with gusts of up to 40mph, according to statistics from the National Hurricane Center.
The winds created by the subtropical storm will border on severe, with enough power to threaten significant property damage, according to the Beaufort Wind Scale.
The wind also harnesses enough power to create damage roofs and bring down power lines.
Weather experts advise to make sure all loose objects outside are secured, and to postpone any unnecessary trips as the strong winds will make driving hazardous.
Oddly the storm, which will be categorised as post-tropical when it reaches UK shores is also expected to deliver warm and humid conditions, along with wind and rain, in the south east of England according to meteorologists.
Temperatures predicted to reach the mid-20s, with possible highs of 25C.
A National Hurricane spokesman said: “Ernesto is expected to become a post-tropical cyclone Thursday night or early Friday, and merge with a frontal zone near Ireland and the United Kingdom on Saturday.”
Alan O’Reilly of Carlow Weather said: “Subtropical Storm Ernesto has formed out in the Atlantic, it is expected to become a post-tropical cyclone Thursday night or early Friday.”
Meteorologists say torrential rain will hit the south and south eastern regions of the UK on Thursday, with the weather clearing up by late afternoon.
Scattered showers will then move in over Scotland and Northern Ireland.
The south-east of the country will feel a warm boost amid calmer weather and warm sunshine, while more showers threaten to hit the North and West on Friday.
Backing up tomorrow’s predictions, a Meteogroup service spokesman confirmed: “On Friday, it will be wet in the northern half of the country and Wales, elsewhere it will remain drier, particularly in the east where there will also be more in the way of sunshine.
“Winds will be brisk from the south west, but strong over Scotland and Northern Ireland. Saturday will be a drier day for many areas, with just a scattering of showers, these mainly in the west.
“The best of the widespread sunshine will be during the latter part of the day and winds will tend to ease as the day progresses.”
A spokesperson for The Weather Channel said: “Ernesto will move into cooler waters in the next 24 hours and transition into a post-tropical system.
“It will then will be picked up by mid-latitude westerlies and arrive over the UK late on Saturday.”
The name Ernesto has been used for seven tropical cyclones in the Atlantic Ocean.
The first incarnation of of the tropical storm appeared in 1982 and formed southwest of Bermuda and dissipated without threatening land.