Dust off those umbrellas, Vancouver. This isn't October 2013.
Last October, Vancouver accumulated a paltry 37.4 mm of rainfall, well below climate averages. Unfortunately, to skiers dismay that trend continued for most of Winter 2013- 2014.
If you're a fan of rain, Van, there's high confidence that next week will bring robust changes with several potent frontal systems impacting the BC coast. It's possible that rainfall amounts over the next 7-10 days for certain regions the South Coast will exceed the amount of rain that's fallen over the past several months! Truly astonishing.
A couple recurving typhoons along Japan's coastline will be responsible for this intense shift in weather as discussed last post — the evidence is mounting. Thanks Phanfone.
Using ensemble model evidence, the conclusion is undeniable.
A rainfall warning may need to be issued for portions of the South Coast for next week, as the jet stream takes direct aim at the South Coast:
- A weak trough is forecasted to dissipate as it slides down the British Columbia coast Friday evening with another shortwave trough moving over the region on Saturday evening — both events bringing precipitation, although the latter looks heavier.
- Monday is now looking considerably less wet, especially for the morning, as a weak upper level ridge slides over Southern BC, which will hopefully delay the onset of the precipitation until at least Monday evening now for Vancouver.
- By Tuesday heavier precipitation reaches all areas of the coast and several models are now indicating a potentially potent low pressure system developing off a favourable jet stream Wednesday evening in the Pacific Ocean.
- Initial rainfall forecast: 50-100 mm+ likely next week with the highest amounts near the North Shore Mountains and Western Vancouver Island and lower amounts towards YVR.
The Long Ranger
A couple long range models are attempting to create a strong, potentially damaging low for Wednesday evening into Thursday. Model data must be interpreted very carefully 5-7 days out, but the Canadian model is also showing hints of a developing system— and currently modeling the track a little further south with a higher pressure.
With West Coast wind storms, the most dangerous often intensity and mature as they make landfall, while the garden variety storms tend to weaken as they arrive in our waters and curve into Haida Gwaii.
There's a type of storm track West Coaster's have to pay special attention to. On the right, climatologist Wolf Reid outlines the most destructive Pacific Northwest wind storm tracks in history; note they all share that similar trademark southwesterly curve.
Ensemble model support also shows our winds substantially increase, Van. Breezy to Windy conditions likely for most of next week.
Freezing levels will also fall from a towering 3500 metres, to a more meager and desirable (for skiers) 1500 metres, ushering in the first significant high elevation snows for the coastal range.
Wax those skis...
Oh, did I mention high elevation snow yet?
Although this is direct model output, this gives an idea of some of the regions that could potentially see some accumulating snow next week (above 1500 metres). Portions of the Vancouver Island Mountain Range including Mt. Washington also may see some accumulating snow, although there's still some uncertainty on where the freezing level ends up, depending on the track of the low(s).
Tune into The Weather Network for coverage of this changing and potentially active pattern in the west.