The incident occurred on Tuesday November 18 and officers are appealing for information.
Police have said the woman, who had been walking her dogs, returned to her vehicle at around 7.55am when she was grabbed by an unknown man and forcibly groped.
She was able to hit and kick out at the man, forcing him to run away.
The suspect is described as in his late 20s or early 30s, around 6′ tall of a slim build with a mole on the left side of his face.
He was wearing a black puffer jacket, black bottoms and black and red trainers.
Armagh, Banbridge, & Craigavon District Commander Superintendent Brendan Green said: “Park users and local residents can expect to see an increased police presence in the area, and in Lurgan more generally, over coming days as we increase patrols in order to keep people safe.
“We remain committed to doing everything we can to protect women and girls, prevent harm and call out unacceptable attitudes and behaviours.”
DUP politicians said the incident is “deeply concerning” and called for CCTV to be installed in the area.
On Tuesday, DUP MP Carla Lockhart said she had spoken with the PSNI and asked for an increased police presence in the area, especially during the winter months when daylight hours are limited.
“There should be no place in our community where lone females cannot go and feel safe,” she added.
DUP Councillor Peter Haire added: “I am concerned to read a social media post in which a mother warns women and girls to be vigilant following an alleged incident involving her daughter this morning near the Lurgan Park gates at Windsor Avenue.
“I’m relieved to hear she was able to get away safely.
“It is worrying that there is no CCTV coverage in this area.”
A spokesperson for the PSNI added that officers investigating this attack are aware that quite a number of people were in and around the park at the time, and believe they have spoken to many of these people.
But officers are asking anyone who has not yet contacted police to please get in touch and share any information or sightings they may have.
“They would also like to hear from anyone who may have captured any kind of footage in the area at the time,” added the spokesperson.
“Please call 101, quoting reference 178 18/11/25. Information can also be provided via our website at www.psni.police.uk/makeareport/.”
You can contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org