UPDATE 2.35pm: Dozens of homes are without power north of Ballarat as storms continue to roll through the region.
Thunderstorms initially struck about 1pm in Ballarat, with hail reported in Bonshaw.
The Powercor live outage map shows about 2000 houses in and around Creswick have no power, while other areas have reported flickering lights.
Fallen trees have also been reported on the Midland Highway (Creswick Road) north of Ballarat, and drivers are urged to take care in wet and slippery conditions.
UPDATE 10.45am: A thunderstorm warning has been issued for Ballarat as the weather continues to heat up.
The Bureau of Meteorology notes thunderstorms are developing in the area between Stawell and Ballarat, almost to Colac, as a pre-frontal trough moves through the west of the state.
The BoM's weather radar shows heavy rain already south of Beaufort, moving towards the south-east.
"A 98kmh wind gust was recorded at Mt William (in the Grampians) at 9.41am," the BoM notes.
"Severe thunderstorms are likely to produce damaging winds in the warning area over the next several hours. Locations which may be affected include Stawell, Ararat, Lake Bolac and Ballarat."
The area remains under a Total Fire Ban, with temperatures expected to hit 34 degrees in Ballarat, and "catastrophic" fire conditions in the Wimmera.
As of 10.30am, it was 29 degrees at the Ballarat airport, with winds up to 39kmh.
A Total Fire Ban has been declared for Ballarat on February 13, with "catastrophic" conditions forecast for the Wimmera.
Ballarat is in the Central district, which will be covered by the Total Fire Ban - the Wimmera, Mallee, Northern Country, South West, and North Central districts will also be covered.
A Total Fire Ban means no fire can be lit in the open air, or allowed to remain alight, from 12.01am to 11.59pm.
The CFA stated the Wimmera and surrounds will face "catastrophic" fire conditions, the highest in the new rating system.
"Conditions in the Wimmera, Mallee and Northern Country will be hot and windy with temperatures reaching around 40 degrees and northerly winds around 40-50kmh before a gusty south-westerly wind change with wind speeds between 60-80kmh," a media release states.
Ballarat has a forecast of 34 degrees with possible thunderstorms in the afternoon and evening.