Kerri, aged 34, left her home address at around 8.20pm today (Wednesday 28 July).
She is described as being around 5ft tall, of medium build, with long dark hair, usually worn in a bun.
She was last seen wearing a black vest top, light coloured denim shorts, white trainers/shoes and was carrying a blue plastic bag.
Officers are concerned for her welfare at this time.
If you have information you can report this by:
Calling 999 immediately if you believe you are with Kerri now or have seen her in the last few moments.
Filling out our online reporting form at herts.police.uk/report.
Speaking to an operator in our Force Communications Room via online web chat at herts.police.uk/contact.
Calling our non-emergency telephone number 101 if you have information about where Kerri has been.