The Met Office has issued a yellow weather warning for rain, which is set to remain until Friday.
This is expected to bring spells of prolonged heavy downpour which may lead to flooding and disruption to travel across Shropshire.
It comes as Shropshire Council said some car parks in Shrewsbury were being closed.
Shrewsbury's Frankwell Riverside Car Park was being shut and workers from the Environment Agency were due to monitor the area.
The main car park in Frankwell was also being closed by Shropshire Council at 11am today.
St Julian's Friar's Car Park was to remain open and be reviewed throughout the day, although the authority said it was "likely to be closed with expected [river] levels".
A council spokesperson said: "Please can Frankwell Resident and Season Ticket Holders move their cars to Raven Meadows Car Park by 11am on Tuesday 19 January as the gates will be locked to prevent issues with cars at risk and issues with two way flow on the entry and exit to Frankwell Main.
"For those needing to park in the town centre and who are looking for the cheapest parking, please use Abbey Foregate Car Park.
"Please can St Julian’s Friar’s Resident Permit Holders be prepared to move vehicles to Abbey Foregate Car Park on the top tier."
Rail services between Shrewsbury and Machynlleth have also been affected and no trains are running between Shrewsbury, Welshpool and Newtown as a result.
See the latest forecast from The Met Office here:
Meanwhile, a flood alert where flooding is possible was issued for the Severn Vyrnnwy confluence after the effects of Storm Christoph.
Consequently, flooding of roads and farmland was expected today(19).
Low lying land and roads adjacent to the river from the Welsh border at Llawnt to Shrawardine near Shrewsbury were set to be affected.
Other locations include Llanymynech, Maesbrook and Melverley.
Further heavy rainfall is forecast over the next 24 hours and the river level was predicted to peak in Llanymynech at between 4.1m to 4.6m Wednesday afternoon.
The Environment Agency said it is "closely monitoring the situation" and has incident response staff checking defences across Shropshire.
Residents in the worst affected areas are being advised to avoid low lying footpaths and roads near local watercourses.