Feeling Foggy?

"Fog is complex." A quote from a fellow weather friend.  

Because there are different types of fog, this type of weather event can occur because of different scenarios - making fog very difficult to forecast at times.

 We usually associate high pressure with nice weather - however high pressure is also associated with sinking air, and that can cause moisture to get trapped at the lower levels.  This results in fog, especially when we have little or no winds.  

However- with that said- sometimes wind is the key to fog.  There are instances when wind can be the cause of the moisture because it can bring the fog that just sits offshore inland... this is common for coastal areas.

(Remember when we said "fog is complex?")

In addition, an inversion will also aid to keep fog around because there is little upward or downward movement of air. In a normal situation air cools with height, however because the cooler air is already below the warm air in an inversion - there is less movement because there is no encouragement for the cool air to sink or the warm air to rise.  At 7am it was 9C at the top of Grouse Mountain and only 6C at sea level at the airport.

So we have all the right ingredients for a fog event for coastal BC - an inversion and sinking air, and since we are talking about the coast - we have an abundance of moisture sources.  And we are still under the influence of a upper level blocking pattern... so...you can expect fog to be an issue over the next few days.

If you're looking for sun - I'd suggest taking the tram up to Grouse or driving up to one of the lookouts - I suspect the view above the cloud and fog will be quite pretty.  Where you can find sun, you can expect highs into the mid to upper teens - for example yesterday it was close to 20 degrees in parts of the Fraser Valley.  However below the cloud, temperatures will be a bit suppressed with highs in the low teens. 

Have a great weekend.