So Where is El Nino?

El Nino has really started to make its presence felt in California over the past few days, with a series of storms bringing lots of rain to coastal areas - just what you would expect during an El Nino winter.  For Victoria, the conventional wisdom is that we tend to experience winters that are warmer and a bit drier than normal during El Nino years.  This year's El Nino has been touted as the largest one ever recorded, so has our winter weather lived up to the expectation so far?  Not really.

First, let's look in a little more detail at how El Nino usually impacts our winters in Victoria.  Over the past 30 winters, there have been 6 moderate or strong El Ninos: 1982-83, 1986-87, 1991-92, 1997-98, 2002-03, and 2009-10.

The table below looks at the monthly mean temperature in Victoria for December through March, comparing El Nino winters with the 30-year average.  Each month between December and March has been, on average, warmer during El Nino winters.  The difference is smaller in December and March (+0.8 degrees) but increases in January and especially February, when it peaks at a difference of +1.1 degrees.

           Mean Monthly Temperature

	Dec	Jan	Feb	Mar
1981-2010 ave.	5.3	5.9	6.5	7.9
El Nino winters	6.1	6.8	7.6	8.7
Difference	0.8	0.9	1.1	0.8

The next table compares average precipitation in Victoria during the same months.  The results are much less conclusive, with December and especially February being somewhat drier during El Nino winters, but January and March being slightly wetter.

    Average Monthly Precipitation (mm)

	Dec	Jan	Feb	Mar
81-10 ave.	95	104	61	51
El Nino	89	111	49	55
Difference	-6%	7%	-20%	8%

One aspect of our winters that has been significantly impacted by El Nino seems to be snowfall.  The 30-year average snowfall for Victoria is 20.1 cm.  However, for the 6 El Nino winters in the past 30 years, snowfall has averaged just 1.4 cm, or 7% of normal.  Now that's a significant difference!

So how has this winter stacked up?  December was 0.9 degrees above the 30-year average, or about what you'd expect for an El Nino winter.  However, that warmth all seemed to come in the first half of the month.  Late December, and so far in early January, temperatures have been below normal.  Precipitation in December was about 25% above normal, while so far in January it has been relatively dry.   So precipitation has been a mixed bag, but that seems to be the trend for El Nino winters in Victoria.  There has been no snow so far this winter in Victoria, so that certainly seems to follow the pattern we've seen in previous El Nino winters.  

For an El Nino that's been hyped as the biggest ever recorded, so far it seems a bit of a let down in Victoria.  The weather has been pretty chilly for about three weeks now.  One thing to keep in mind though, is that El Nino tends to have its greatest impacts in Victoria later in the winter, peaking in February.  Let's hope this monster El Nino brings us a really mild and dry February!