Gauging the rain to come

  • Vancouver Island Inland Sections Forecast - No watches or warnings in effect.

    Forecast Issued 4:00 PM PDT Saturday 21 April 2018 - Saturday night: Mainly cloudy with 30 percent chance of showers. Low plus 2. Sunday: Mainly sunny. High 15. UV index 5 or moderate. Sunday night: Clear. Low plus 1. Monday: Sunny. High 19. Monday night: Cloudy periods. Low plus 3. Tuesday: A mix of sun and cloud. High 19. Tuesday night: Clear. Low plus 5. Wednesday: Sunny. High 20. Wednesday night: Clear. Low 6. Thursday: Sunny. High 21. Thursday night: Clear. Low 7. Friday: Sunny. High 19.

  • Current Conditions
    Temperature
    5.3° C
    -1.8 ° C/hr
    Barometer
    103.1 kPa
    rising
    Wind
    NNW1 km/h
    gusting 0.0 km/h
    Humidity
    89 %
    Rain Rate
    0.0 mm/hr
    Wind Chill
    NA° C
    Heat Index
    6.3° C
    Dewpoint
    3.7° C
    UV
    0.0
    Solar
    0 W/m2
    Last Updated: 23:25:00 PDT
    Station Reports Delayed
    7 minutes
    Showing Nearest Official Station

    Observed at: Port Alberni 10:00 PM PDT Saturday 21 April 2018
    Click to Refresh or See All Conditions
  • Day Almanac
    Day's Rain
    2.3 mm
    Day ET
    0.0 mm mm
    Rain Storm
    NotAvailable mm
    Civil Rise
    05:40
    Moon Phase
    Waxing crescent (43% full)
    Civil Set
    20:56
    Day Length
    13:17:51
    Day High
    11.7° C @ 16:52 Tdy.
    Day Low
    5.9° C @ 03:15 Tdy.
    Day High Rain Rate
    3.3mm/hr @ 00:20 Tdy.
    Day High Barometer
    103.07 kPa @ 22:29 Tdy.
    Day Low Barometer
    101.62 kPa @ 00:15 Tdy.
    Day Low Windchill
    3.7° C @ 05:55 Tdy.
    Day High Heat Index
    11.7° C @ 16:52 Tdy.
    Day High Wind Gust
    S 21.6km/h @ 15:00 Tdy.
    Day High Solar Radiation
    1187W/m2 @ 12:01 Tdy.
    Day High UV Index
    5.2 @ 13:39 Tdy.

There is no doubt it will rain starting Thursday or Friday. In fact, as I type this there is a light mist falling in Qualicum.

First, it’s worth remembering how much rain we need, which is a lot even for us on the West Coast.

Not since 1896 (in Beaver Creek) and 1929 (at City Hall) has there been a summer and fall this dry in Port Alberni. However, already this October has been more extreme than 1896. If you look at the daily data, rain fell on and off throughout October 1896. In 2012 we have yet to register rain in October. (October 1929 was a more typical month with over 180mm falling throughout)

The totals are most compelling though so again, July-October, 1896 got 159mm, 1929 got 214.9mm, and 2012 has 36.2mm so far. So we need over 122.8mm to dodge the 1896 record. (Apologies I’ve said 140mm in the past, bad in-head math on my part)

So will we get it and avoid the record? It is still hard to say. Initially this weekend’s rain looked intense. But it has flipped and flopped. Here is the latest GFS prediction.

20121010-073338.jpg
It shows a very merger start with a strong punch on Saturday and Sunday night totalling over 144mm!

That would take care of the record.

However, the GFS often overestimates. So what does the Canadian model say? Here are the accumulations from Friday through Monday with graphics available here.
20121010-073726.jpg
10mm on Friday.

20121010-073714.jpg
30mm on Saturday

20121010-073721.jpg
35mm on Sunday

20121010-073732.jpg
50mm on Monday

Total: 125mm

That would also put us over the 1896 amount and avoid setting a new record.

So now we wait and see if the forecast holds. There is rain in the long range forecast too… But we will address that maybe on the weekend. Rain amounts are often the most difficult to predict, but whatever we get, it will be a blessing for local rivers and the people and animals that depend on them.