Rainfall warning: 20 to 30 mm Monday, snow overnight

After a weekend of snow pellets and freezing rain, there's now a rainfall warning from Environment Canada, applying to all of Waterloo region and Wellington County. 

At times, the rainfall will be heavy, according to the weather authority. It warned to expect 20 to 30 millimetres of rain by the time the system clears to the east after noon today.

"Extra care should be taken during this morning's commute. Standing water may be potentially hazardous on poorly drained roads and highways due to the weekend ice accumulation," suggested Environment Canada.

After noon, there remains a 40 per cent chance of rain, with a high of 3 C and a 60 per cent chance of rain Monday evening.

We're probably talking like decades before we've seen something of this nature- Frank Seglenieks ,  co-ordinator  of the University of Waterloo weather station

The water could also cause isolated flooding in low-lying areas — and homeowners are advised to clear as much ice as possible to help with storm flow. 

Bus detours in Cambridge

The road conditions forced bus detours in Cambridge, on routes 55 St. Andrews, 58 Elmwood and 75 Saignaw.

• Route 55 St. Andrews: Grand Ridge Drive, Inverness Drive, Culham Drive, Tait Street, Fourth Avenue are closed. Stops 2253, 2254 and 2255, 2256, 2257, 2258, 2259, 2260, 2261, 2262, 2263, 2264 and 2265 are are closed. Passengers should use temporary stop 2252 Southwood at Wedgewood until hazardous road conditions are cleared.
• Route 58 Elmwood: McNaughton Street: Shade Street to Chalmers Street is closed. Stops 2119, 2120, 2121 and 2122 are closed. Passengers should use temporary stop 2118 Lauris at Linnwood until conditions are cleared. Stops 2123 and 2124 closed. Passengers should use temporary stop 2125 Main at Harris until hazardous road conditions are cleared.
• Route 75 Saignaw: Stop 1354 is closed. Passengers should use temporary stop 1352, Essex Point at Burnett Ave until hazardous road conditions are cleared.  

In addition to the temporary route changes, Grand River Transit also warned riders to expect delays due to weather and road conditions.

Meanwhile, parks, natural areas and trails managed by the Grand River Conservation Authority remain closed. 

"Ice accumulating on trees and branches is increasing the risk that they may fall down under the added weight" the conservation authority said, adding it could take several days for staff to assess and clear any damage.

Snow Monday night, Tuesday

Though the rainfall warning is expected to lift this afternoon, another two centimetres of snow is in the forecast for Monday night, with a low of –2 C.

"Even [Tuesday] is still looking a little bit messy," Frank Seglenieks co-ordinator of the University of Waterloo weather station told The Morning Edition on Monday morning. Environment Canada forecasts an additional two centimetres for Tuesday.

This kind of weather is extremely rare, especially for this time of year said Seglenieks. Ice pellets and freezing rain take a "perfect storm" of conditions.

"Certainly having [an ice storm] in April I think is really the big difference. Last one was in December [2013], you hear it as a January, February thing. So to have it this late in the season, that makes it rare — and we're probably talking like decades before we've seen something of this nature."

But there is hope in sight. Seglenieks assures proper spring weather is on the way.

"Getting towards the end of the week, it's going to warm up a bit — and next week, hold on to your hat. We may actually get a temperature above average!" said Seglenieks. "We've only had one so far this month."