After another messy evening last night, I doubt anyone wants to think about the next system. There was quite a bit of freezing rain over Eastern sections of Nova Scotia.
Elsewhere, there was a range of snowfalls…. adding to the substantial snow already on the ground.
Thursday snowfalls
The next weather system will move in Saturday night, with snow likely changing to rain over the southern Maritimes by Sunday morning. It’s too early for detailed amounts. However, it is reasonable for Nova Scotia to expect up to 5cm of snow followed by 20 to 30mm of rain. In PEI and Southern New Brunswick the precipitation amounts will be more split between rain and snow; with something in the range of 10-20cm snow in parts of central New Brunswick that do not change to rain.
February rain is not good, and we might consider preparing for the potential impacts now.
1. Flooding: Some of the 20-3omm of rain will runoff frozen surfaces, cause some snowmelt and pool in low lying areas, including roads. Ensuring storm drains are clear will help alleviate this mess.
2. The weight of snow will increase by any rain that is absorbed by the existing snowpack. Due to past rain and ice pellet events, the snow is very dense in some areas like Halifax. In my yard, less than 50cm of snow has at least 175mm of water equivalent contained in it. Roofs in Halifax have been designed for weights equivalent of 225mm of water… so some snowpacks may be approaching critical weights, especially if they absorb more rain on Sunday.
I would suggest if you have more than 60cm of snow (2 feet) piled on your roof or deck in Halifax, you might consider getting professional advice regarding having it safely removed before the rain.
Some advice is available from the National Research Council.
In PEI and Southern New Brunswick, the snow load design criteria is higher than in Halifax (in the 300mm range). The reports I have seen from those areas are in the range of 125 to 150mm, since the precipitation has been mostly snow. Any rain will certainly make the snowpack more dense.
3. Icy surfaces: The rain falling on ice covered roads, walkways or parking lots will result in extremely slippery surfaces. Take advantage of fine weather Saturday to chip away, sand or salt these surfaces to at least rough the surface up.
4. Freeze: It will drop below freezing Sunday night, and be quite cold on Monday. Important to try and remove slush or standing water on Sunday.
I’ll update this post as new information arrives.
