A frontal system, mammary clouds, and the dread of snow

A pineapple express-like system is slamming the north/central coast. Amounts at one observation station near Bella Bella  has recorded over 100mm in 36 hours.


Tomorrow is looking high and dry tomorrow, with the ridge hanging on the further south you go. Temps for Vancouver will peak around 4 or 5 o'clock tomorrow between 16-18 degrees. Not really baking, but for October 6th... we'll take it.

After our beautiful sunshine, look for some atmospheric indigestion with a system approaching from the Pacific, and it's associated frontal system will push through the Lower Mainland late in the evening.  

Exactly a week ago we had an abnormally powerful cyclone (for September)  at 975mb push across Vancouver Island. We won't be seeing an extraordinarily deep low, but rather a typical 990-998mb low. Unlike last week, we don't have a supercharged jet streak that promoted such explosive cyclogenesis.

I'm also going to highlight a couple severe, historical windstorms this week. Stay tuned. 

FYI: Canadian Model in particular is predicting a 991 low at 5pm Sunday.

Sunday Evening October 6th .jpg

Such a typical October storm for the area, it's barely acceptable to blog about it....  


It's only a matter of time...but  I'm dreading the predicted onslaught of "OMG WHEN WILL IT SNOOOOOOWW?!!?!" 

This sends shivers down the spine of many forecasters in this region, because predicting snowfall along the coast is VERY tough. This isn't the prairies. This isn't Edmonton. We have the mild Pacific Ocean to our west which helps  to moderate our temperatures year-round.  

Normally a typical conversion for snow to rain is 10:1. 1 cm of rain will give you 10cm of snow. This means that snow forecasts are extremely sensitive to the amount of precipitation. Even small fluctuations in what's forecasted will have a big, big impact when it comes to snow amounts.

And then there's the small elevation changes...rain at sea level ...go up 100-200 meters...BOOM snow!

I could go on and on...

So my strategy this fall/winter is to give you the facts. No hype. Just facts.

I'll tell you what I know about impending snow events without the media sensationalism.

How much snow would you like this year Vancouver?



As a bonus I'm going to highlight my favourite cloud type:

The mammatus cloud (AKA mammary clouds!)


 As you would expect, very turbulent and unstable air is needed to promote this cloud formation...  

What makes them unique?  They tend to form with descending air, after a thunderstorm has passed...Not your typical cloud! 

Anyway, they're beautiful!