A very rainy day in Victoria!

Up until Sunday, it had been a dry start to the year, with just 81 mm since January 1, compared with our normal of 134 mm in the first 45 days of the year.  Then came yesterday (February 15) - what a very rainy day!  There was 61.6 mm of rain recorded at Victoria Gonzales.    Average rainfall for the entire month of February is 61 mm, so that's a month's worth of rain in one day.  It was also far more than the 47 mm of rain we had in the entire month of January 2016, even though we had 20 days with measurable precipitation during that month.  Yesterday's rainfall was quite rare for Victoria.  It certainly blew away the old record for the date of 28.2 mm of rain back in 1949.  It was the most rain recorded at Victoria Gonzales in a single day since since November 6, 2006 - more than 9 years ago.  It was also the second rainiest February day ever recorded at Victoria Gonzales in more than 117 years of recording-keeping, and the 17th rainiest day ever recorded in any month!  On average, Victoria gets a day like yesterday with more than 60 mm of rain only once ever 7 years.

As the chart below shows, yesterday's rain completely closed the rain deficit we'd had so far this year.  The blue line shows the 30-year average rainfall to date while the red line shows the cumulative total rainfall for 2016.  You can see that we've been well below average so far this year, but with yesterday's deluge, we have jumped to just above average.  The green bars show the daily rainfall amounts, and you can see how much rainier yesterday was compared with any other day this year.

Why did we get so much rain?  There were two factors.  The first was an atmospheric river or "pineapple express" carrying subtropical moisture directly to our area.  Usually during a pineapple express, as the moisture streams in from the southwest, Victoria is protected by the rain shadow of the Olympic Mountains, and our rainfall totals are a lot less than areas to the north and west of us.  However, this pineapple express, rather than coming from the southwest, was coming from a more westerly direction.  When that happens, the rain shadow shifts from being northeast of the Olympics (and usually including Victoria) to be more east of the Olympics (giving more protection to Seattle).  Westerly flows are often when Victoria will get it's heaviest rainfall.   When I saw in the forecast on Sunday that there was going to be an atmospheric river coming at us from the west, I expected we'd get more than our usual light showers!

Below is an interesting radar image from about noon yesterday.  Instead of being in the hole of the donut, as we often are, Victoria is right in the bulls eye!