Grace Clarke, 12, has been missing since leaving her house in the Hollingdean area of the city at about 9pm last night. She is described as white, 5ft tall with long dark hair.
She was wearing a black hooded top, black leggings and Nike Sliders.
Brighton Sergeant Simon Marchant said: “We, and her family, are enormously worried about Grace and would ask her, if she is reading this, to make contact with either us, her family or a responsible adult.
“There is a possibility she may be taking shelter from the wind and the rain either in wooded areas in the Varndean or Hollingbury areas, or potentially in outhouses or sheds in people’s gardens.”
“We are urging everyone to check their premises for signs of Grace and to keep an eye out for her.”
Storm Ellen makes its presence felt up the south coast in Devon
Police confirmed the good news via Twitter
However, there was a happy end to the story.
This morning Brighton and Hove Police tweeted: “Great news! We are delighted to update you to say that #missing Grace Clarke has just been found safe and well by officers in #Brighton
“We would like to thank each and every one of you who helped us by RT’ing our post and getting in contact with information. #teamwork
Storm Ellen brought winds of up to 70 miles per hour yesterday.
Strong winds batter the sea front in Guernsey, one off the Channel Islands
A holidaymaker died and a teenage boy is recovering in hospital after they got into difficulty in the sea off the Cornish coast yesterday as Storm Ellen struck, police said.
The man, who was in his 50s and from the London area, was pulled from the water near Helston on Thursday afternoon but was confirmed dead shortly afterwards.
The teenager – who is related to the man – is in a stable condition in hospital in Truro following the incident at Church Cove in Gunwalloe.
Storm Ellen to bring robust 30C heatwave back to Europe [MAPS]
London weather forecast: When will Storm Ellen hit capital? [FORECAST]
UK weather warning: Severe storm with thunderstorms and tornadoes [WARNING]
Waves lash up at a passing train in Devon
A Devon and Cornwall Police spokesman said: “Police were called at 2.20pm following reports that a man and teenage boy were in difficulty in the sea.
“Officers attended the scene, along with HM Coastguard and helicopter, the RNLI, and fire and ambulance services.
“Both males, who were from the same family, were recovered from the sea. Despite best efforts by all, the man, who was in his 50s, was confirmed deceased at the scene.
“The teenage boy was airlifted to Treliske Hospital, where he is believed to be in a stable condition and recovering with his next of kin present.”
Meanwhile, in Ireland, about 50,000 homes and businesses were left without power on Thursday.
A statement issued by energy company ESB said: “We are advising all those impacted by outages that they should prepare to be without electricity overnight and into tomorrow – with some customers potentially without power beyond that.”
It confirmed it expected that 50,000 homes and businesses will remain without electricity on Thursday evening.
“Crews will continue working tonight and will mobilise again at first light to restore the remainder through the course of tomorrow, Friday.”