Update 10PM – Flood Watch Continued for Somass/Sproat – Warning for East Van Isle.
The BC River Forecast Centre has issued a Flood Warning for:
- East Vancouver Island including the Browns River, Tsolum River, and surrounding creeks in the Bowser, Courtenay and Campbell River area
The BC River Forecast Centre is maintaining a Flood Watch for:
- Central Vancouver Island including Sproat River, Somass River and surrounding creeks and tributaries near Port Alberni
The BC River Forecast Centre has also issued High Streamflow Advisory for:
- West Vancouver Island including Tofino Creek, and surrounding creeks and tributaries
- North Vancouver Island including Zeballos River, Salmon River, Gold River, and surrounding creeks and tributaries
The public is cautioned to stay clear of rivers during rain events due to quickly flowing water and potentially unstable riverbanks.
The River Forecast Centre will continue to monitor conditions and will provide updates as conditions warrant.
Update 4PM Rainfall Warning continued. See below for Flood Watch.
EC is expecting another 10-20mm of rain to fall before the rain ends around midnight. Flood Watch continues. And there is more on the way for the weekend, so stay tuned. If you need sandbags, there is sand and bags at the City of Port Alberni Public Works yard on 6th Ave. If you see any flooding happening due to clogged drains or anything like that please let the city know.
Issued at 2016-11-02 22:59 UTC by Environment Canada:
Rainfall warning continued for:
East Vancouver Island, B.C. (081300)
West Vancouver Island, B.C. (081400)
Inland Vancouver Island, B.C. (081500)
Current details:
Rain, at times heavy, is expected.A vigorous frontal system has brought heavy rain to coastal BC today. Total accumulated amounts of 80-120 mm have been recorded across West Vancouver Island, Port Alberni, and between Fanny Bay to Qualicum Beach. Heavy rain will continue this evening with an additional 10-20 mm expected.
Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible.
UPDATE 12PM WEDNESDAY – FLOOD WATCH ISSUED FOR SOMASS/SPROAT SYSTEMS
Issued at 10AM this morning by the River Forecast Centre.
Flood Watch: East Vancouver Island and Central Vancouver Island (NEW)
High Streamflow Advisory: North Vancouver Island and West Vancouver Island (Maintained)
UPDATED: November 2 2016 10:00 AMThe BC River Forecast Centre is issuing and upgrading to a Flood Watch for:
- Central Vancouver Island including Sproat River, Somass River and surrounding creeks and tributaries near Port Alberni
- (NEW) East Vancouver Island including the Browns River, Tsolum River, and surrounding creeks in the Bowser, Courtenay and Campbell River areaThe BC River Forecast Centre is maintaining a High Streamflow Advisory for:
- West Vancouver Island including Tofino Creek, and surrounding creeks and tributaries
- North Vancouver Island including Zeballos River, Salmon River, Gold River, and surrounding creeks and tributariesA series of Pacific storms are impacting the BC Coast. The first system passed overnight, bringing rainfall amounts in the 70-100 mm range through Central Vancouver Island and Eastern Vancouver Island, 50-150 mm through Western Vancouver Island and 20-40 mm elsewhere on Vancouver Island.
Rivers have been rapidly responding in response to this rainfall. Current conditions include:
- Browns River near Courtenay (08HB025) is flowing at approximately 80 m3/s, with a high of over 110 m3/s overnight. This is approximately a 2-year return period flow
- Tsolum River near Courtenay (08HB011) is flowing at approximately 70 m3/s, below the 2-year return period flow
- Ash River below Moran Creek (08HB023) is flowing at approximately 80 m3/s, below the 2-year return period flow
- Sproat River near Alberni (08HB008) is flowing at approximately 100 m3/s, below the 2-year return period flow
Heavy rainfall is currently being observed across the region, with current rainfall rates in the 2-5 mm/hr range. Current forecasts from Environment Canada indicate the potential for an additional 30-150 mm of cumulative total precipitation across Vancouver Island with the highest amounts across West Vancouver Island and Central Vancouver Island. Detailed weather information is available at the Environment Canada Weather Alerts website.
Rivers are expected to see continued rapid rises through Wednesday. Current hydrologic modelling shows potential for flood conditions to occur in the Central Vancouver Island and Eastern Vancouver Island regions, with forecast flows in the 2-year to 10-year return period range.
At this time, significant storm surges are not expected, further details are available at the Storm Surge BC website.
The public is cautioned to stay clear of rivers during rain events due to quickly flowing water and potentially unstable riverbanks.
The River Forecast Centre will continue to monitor conditions and will provide updates as conditions warrant.
Rainfall Warning Continued
Issued at 2016-11-02 14:09 UTC by Environment Canada:
Rainfall warning continued for:
East Vancouver Island, B.C. (081300)
West Vancouver Island, B.C. (081400)
Inland Vancouver Island, B.C. (081500)
Current details:
Rain, at times heavy, is expected.A pair of weather systems will bring heavy rain to coastal BC today. Total rainfall amounts will exceed 100 mm for West Vancouver Island, Inland Vancouver Island, and Port Alice, and up to 70-90 mm in the Fanny Bay to Qualicum Beach area.
Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible.
Be careful out there this morning. Lots of water and pooling on the highway and low visibility.
Rainfall Warning Issued at 4PM Tuesday
Total rainfall amounts will exceed 100 mm for West Vancouver Island, Inland Vancouver Island, and Port Alice, and up to 50-75 mm in the Fanny Bay to Qualicum Beach area.
It’s November 1st and not only does that mean our first big November storm is on the doorstep, but it also means that there has been a big upgrade to the forecast models that you see most of this website. If you want to skip all this and get to the forecast, click here.
First, I should explain the change in models, since you’re going to see them with the forecast of the upcoming storm. Most of the imagery you see here comes from what seem to be one of the most reliable models we have available to us in the area. They are produced at the University of Washington (State) and we are simply lucky that we are physically close enough to the 49th Parallel that what they produce covers us.
But sometimes they didn’t cover us… most notably, the ultra high quality 1.3km resolution products just missed us by a few kilometres.
Well, as of November 1st that high resolution UWash model has been expanded to include more of Oregon and Idaho, and also about 30km more of Southern BC! That means us!
Below is a “before” picture of the previous coverage. It shows tomorrow’s (Wednesday) rain between 8AM-11AM produced by the 1.3km model yesterday morning. Notice the Alberni Valley is just outside of the top of the picture. (Click for larger)
Below is the same forecast time, Wednesday 8-11AM. Produced by this morning’s run of the model! We’re in! (Along with Oceanside, Courtenay, the Sunshine Coast and almost Powell River too.)
This means that instead of mostly using the 4KM resolution picture for our area which looks like this:
Now I can use the 1 1/3km resolution picture that looks like this:
And if I zoom in to our particular area of Vancouver Island which I often do, instead of looking like this for the 24 hour total of rainfall expected on Wednesday:
I can now zoom in twice as much so now looks like this:
See the difference? All those squiggly grey lines are the mountainous terrain on Vancouver Island. There are a lot more of them in the high resolution image as it captures that level of detail and tailors the forecast more specifically. So for us in the Alberni Valley it has a much better idea of what is actually happening in the Valley itself because it takes it in 1.33km chunks instead of 4KM.
You can clearly see, in the middle-left of the picture the sharp (closely lined) contours of the Beaufort Range running diagonally away from the top of the Alberni Inlet. The empty area beside them is the bottom of the Alberni Valley.
So now, we can see what will happen on the Hump (the little portion of salmon colour pointing diagonally up and to the right NE away the head of the Inlet in the picture) as opposed to Highway 4 around Sproat Lake (in bright blue and green).
Most importantly, it should be able to differentiate between wind and rain totals at the head of the Inlet, in the City versus in the Valley in Beaver Creek and Sproat Lake. For things like rainfall and wind speeds, that will be important in our heavily variable micro-climates when the weather gets rough.
One change that will occur though is around timing. The 1.3km high res forecasts are the last to complete every update (because they are the most complex). They usually complete around 3PM or 3AM for each twice-daily forecast as opposed to the 4KM imagery that completes by around 11AM. This should not matter for my normal early morning posts as they runs from the night before will have fully completed by 6-8AM. But when making updates to that forecast I might end up looking at the 4km models at 11AM to see if there are any big changes and then again at 3PM to see if the morning high res stuff to see more detail.
The 1.3km models also only cover a very short term period. Up to 72hrs/3days out. So I will use the 4KM stuff for medium range (up to 84/3.5days out) outlooks and the 12KM stuff for the long range.
Onto the Upgraded Forecast for tonight!
So what does the newly expanded high-res model say?
It’s gonna rain a bunch! ;+)
…..
OK ok… some detail.
First, here is that 24 hour picture again for between 5PM Tuesday and 5PM Wednesday. The City and Alberni Valley can expect up to 33-65mm (pink). The Sproat Lake area and points further west areas can expect between 60-130mm (black) with peaks of 130-200mm (red) or more (white) for south facing high terrain on the West Coast.
Also notice the black in areas near Buckley Bay and Denman and Hornby Island up to Courtenay on the East Coast.
Those are noted in the Rainfall Warning for the East Coast of Vancouver Island.
A pair of weather systems will bring heavy rain to coastal BC tonight and tomorrow. Total rainfall amounts will exceed 100 mm for West Vancouver Island, and Port Alice, and up to 50-75 mm in the Fanny Bay to Qualicum Beach area.
The strongest period of rain will be in the morning on Wednesday between 5AM and 8AM.
We will receive between 8 and 16mm of rain in that period. Western reaches of Sproat Lake will get about double that.
It will back off a little bit through the midday but then pick up again between 2PM-5PM with the same 8-16mm in that 3 hour period.
It will back off again after that and through the night but one final push will happen in the 5-8AM hours of Thursday morning.
The two day total for the event between Tuesday 5PM and Thursday 5PM will be in the 60-120mm range for our area.
There should not be any wind with this event. However, the newly expanded high resolution coverage does allow us to see those differences in terrain. Particularly close to the Horne Lake area where tonight it shows a region of very strong winds on the top of the ridge near Horne Lake. Anecdotally that would make sense given Horne Lake’s exposure and elevation. Cool to see confirmation of that in the computer models.
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