Significant Weather Notification, Heavy Rain and Strong Winds for B.C. Coast, January 10-13th 2021

Notice Date

Issued: January 8, 2021 at 15:10 PST

Weather Event Impacts:

·         Localised flooding due to heavy rain adding to recent high rain totals and groundwater saturation

·         Possible low land flooding as has been experienced in the recent week

·         Power outages possible due to strong winds causing damage to trees

·         Possible storm surge concerns due to king tides early next week (communities adjacent to Salish Sea)

·         Elevated landslide and washout risk to vulnerable slopes and culvert infrastructure

·         Disruption to marine transportation due to strong winds and rough seas


·         Beginning Sunday and ending Wednesday (January 10 – 13th 2021)

·         Multiple Pacific low pressure systems will move onto the BC coast over the next several days

Key Points:

·         All of the B.C. coast saw a wetter than average December and early January.

·         Impacts have been tied to the length of the active storm cycle on the coast dating back to early to mid-December and are forecast to continue into next week.

·         The active storm pattern in the Pacific Ocean continues on the B.C. coast in its path. 

·         Low pressure systems will bring multiple rounds of strong winds and moderate-heavy precipitation.

o   Prelude: Saturday there will be a first frontal wave over most of the coast ending on Sunday late morning.

o   First Act: Sunday evening & Monday, expect another wet and windy system affecting the entire coast.  This system taps into subtropical moisture and will generate intense rainfall.

o   Crescendo: late Monday into Tuesday, another Atmospheric River will again barrel into the coast and bring heavy rain and strong winds. 

·         There is a lot of uncertainty about the exact timing each of these storms, but they will come frequently, occurring almost on a daily/nightly basis until middle of next week. 

·         Preliminary rain totals: Widespread 100+ mm/ 96 hours and higher totals still for SW facing slopes, ranging from 150-200+ mm of rain/ 96 hours (Sunday into Wednesday)

·         Winds: Sunday and Monday – strongest winds (warning level winds 90+ km/h) north of Vancouver Island up to Haida Gwaii

       Tuesday – strongest winds seem to mostly affect south of the Central Coast and Vancouver Island.

·         Outlook: a relative weather pause on Wednesday and part of Thursday but there are indications that more storms are brewing for late next week as well. For the South Coast, a quieter period looks to take shape late next week into the weekend.  

·        The River Forecast Centre (RFC) may issue advisories if required as the event draws nearer.

·        Preliminary storm surge is estimated by Dr. Scott Tinis at 40 cm for Point Atkinson on Tuesday 12th January, he points out that Courtenay/BC Hydro might be interested due to the potential for flooding around the river discharge.


Forecast confidence:

High – regarding the stormy pattern.

Low – regarding timing, wind speeds and precipitation amounts.

For updates, please monitor upcoming weather forecast and possible warnings:

Weather Warnings:

ECCC Daily Weather Blog:

River Forecast Centre Advisories:

BCHydro Power Outages:

Storm Surge BC: