Puking Mountain Snows, a Powerful Pacific Low, and a Post-Christmas Pattern Change

the three hour pressure change map is telling, especially for the Pacific NW which is experiencing the sharpest pressure drops on the continent at this hour ahead of the stormy weather

the three hour pressure change map is telling, especially for the Pacific NW which is experiencing the sharpest pressure drops on the continent at this hour ahead of the stormy weather

A 985 mb low is poised to cross northern Vancouver Island early this morning with peak winds likely early this morning.

The parent low is currently NW of Haida Gwaii at around 970 mb, and is a very mature cyclone churning in the Gulf of Alaska. 

A secondary frontal system and short wave is barreling down on the the coast for this afternoon and a secondary surface low forms between landfall; the pressure gradients are looking fairly significant.

Wind velocity could briefly touch tropical sustained strength Saturday morning for northern portions of Georgia Strait before dissipating by the evening. Take a look as the wind forecast peak ahead of the low pressure system crossing Vancouver Island (atmospheric pressure = grey line)

The occluded front wraps behind the low and may give another bout of strong winds, but some uncertainty remains on the exact strength for the second peak:

The trusty high resolution WRF-GFS also indicates some wind gusts may approach 90 km/hr for northern portions of Georgia Strait; consequently, ferry cancellations are possible this morning. 

The Canadian high resolution model is also indicating high winds especially between YBL and YQQ with sustained winds between 35-40 knots with storm force gusts possible. The low pressure centre is tracking too far north to greatly impact the Lower Mainland.

Puking Snows?

Yes, according to the official back country skiing glossary of Canada it is perfectly acceptable to use puking to describe a ferocious snowfall. 

Puking: Heavy thick snowfall that accumulates to form good powder snow and freshies for skiing. 

Source: http://backcountryskiingcanada.com/index.php?p=page&page_id=glossary

The good news for skiers unlike the past two weeks, the forecast atmospheric river is aimed south of us which will provide us with relatively low snow levels during this event. Mt. Washington on Vancouver Island is finally able to open today a few days later than my mid-month prediction, but better late than never. 

Some positive news for the local ski hills on Vancouver Island; heavy snow is currently puking over the ski hills as I type this, with temperatures at 1100 metres at -1C and -3C at 1500 metres.

Freezing levels will spike a little today and be the highest during the afternoon for the next 7-10 days, then fall to between 3000-4000 feet (1100 metres) into early next week.

Live Cam:

Tides will also be abnormally high the following week; therefore, some of the highest tides of the year affect our coastlines. Some tides will approach 5 m along the coast around Christmas time; a serious storm at this time of the year is especially dangerous so forecasters have to be extra diligent. 

The forecast high tide Christmas morning for Comox is 5.25 m, so it bears watching. To put this in comparison the coastal erosion earlier this month was between 30-40 cm lower!

Fortunately, no potent wind storms are currently forecasted around this sensitive time period. 

What about the rains?  

Rainfall forecast through Sunday evening:

December 25th Snow Chances?

Don't feel bad Vancouver, even some cities in the east may struggle to hold on to their respective snow pack, as suggested by meteorologist Michael Carter who takes a look at some GFS snow model guidance.

Find out what Western Canadian cities may win the White Christmas jackpot on the 25th...

Report active weather to #BCstorm and tune in to  The Weather Network as we bring you the latest on this BC active weather!