According to a weather expert at the University of Reading, Dennis is one of the strongest North Atlantic storms in the last 150 years.
The system will come near the record low pressure recorded for a storm.
Forecasts had the pressure of this storm measuring at 18-921mb (millibars).
Stephen Burt, a weather historian at the University of Reading told CNN: “The North Atlantic pressure record is 912-915mb, on 10 January 1993.”
“There are only a handful of depressions known to have fallen below 920mb within the last 150 years or so.”
Luckily the country has escaped the worst of the weather as most of the storm will miss the UK.
But Storm Dennis is expected to bring strong winds and a lot of rain to the UK this weekend.
Some areas of the UK have been issued amber weather warnings for rain as flooding is expected.
Weather warnings for strong winds have also been issued as some parts could see 70 mph gusts.