Brace Yourself Vancouver. Fall is Coming.

Vancouver. Brace yourself. Fall is Coming.

Precipitation Analysis (NWS) highlighting just how dry portions of the Pacific Northwest have been.  1-2 inches or 30-60 mm the past two months is light precip and below normal when compared to climate normals. Note: grid only covers CONUS, white portions in Canada are omitted from the grid

Precipitation Analysis (NWS) highlighting just how dry portions of the Pacific Northwest have been.  1-2 inches or 30-60 mm the past two months is light precip and below normal when compared to climate normals. Note: grid only covers CONUS, white portions in Canada are omitted from the grid

There's not much to say. The past couple of months have been filled with bountiful blue sunshine and warm, sunny days.

In early May I wrote about how Vancouver has one of the driest Canadian climates from May-October.

Well, talk about verification this summer...

Although this is typical during the summer months, the numbers have been quite striking and above normal in regards to 2m temperatures.

This July and August temperatures have been exceptionally pleasant averaging daily highs around 23 or 24, with much warmer temperatures inland. You have to remember this is somewhat unusual because for July and August Vancouver International Airport averages a measly 22C (1980-2010 climate normals).

But, when compared with the historic heat wave of July 2009 there's NO competition. This significant weather event in particular featured coastal stations recording temperatures at nearly 35C.

Unprecedented for #YVR and extremely warm even for such cities as Toronto and Montreal. 

Currently, I'm forecasting a smooth although abrupt transition to fall, which surprisingly looks like it will line up with the official fall equinox next week.

But first... British Columbia, and even Alberta you're in for some extremely warm temperatures this coming weekend, and I'll provide the evidence as to why... Hang on, weather nerds, summer is going out with a bang!

Great Model Support Giving a High Confidence Forecast

Green: GFS Red: Nam showing 500MB heights forecasted for Saturday. Note the obvious ridging over southern BC

Green: GFS Red: Nam showing 500MB heights forecasted for Saturday. Note the obvious ridging over southern BC

GFS temperature anomaly map for Sunday evening. Certain regions in BC and AB will be 10-13C above climate normals

GFS temperature anomaly map for Sunday evening. Certain regions in BC and AB will be 10-13C above climate normals

Warmest Day BC: likely Sunday with the provincial hot spot somewhere between 32-33C

Warmest Day AB: Most likely Monday as the ridge slides east with temps possibly approaching 30C in some municipalities. 

The GFS, ECMWF, GEM all have support for this along with their ensemble model counterparts. Models also indicate a thermally induced trough will develop off the Continental US (CONUS) by the weekend, which will work to strengthen offshore gradients giving many communities a shot at record-breaking temperatures on Sunday/Monday.

The marine push on Monday will be abrupt with a possible cold front approaching the coast as the upper level high pressure ridge slides east.

The Long Ranger

Often when looking at ensembles a couple techniques can be used to group possible outcomes together. I'll often glance at these clusters to look at possible solutions. The second image below is also picking up on this anomaly in the Pacific and the significant changes to Vancouver's weather next week.

The GEFS, shows most if not all members showing troughing in the Pacific next week, indicating the Gulf of Alaska storm track is open for business as the upper level ridge slides east

The GEFS, shows most if not all members showing troughing in the Pacific next week, indicating the Gulf of Alaska storm track is open for business as the upper level ridge slides east

GEFS shows a strong anomaly with lower than normal 500 mb heights in the Pacific so our first Pacific Storms are possible at the end of September

GEFS shows a strong anomaly with lower than normal 500 mb heights in the Pacific so our first Pacific Storms are possible at the end of September

And yes, strong, damaging storms are possible at the end of September. Flash back to last September and a potentially dangerous wind storm was narrowly avoided in Vancouver.

GFS model forecast 72 hours out last September indicating a potentially damaging wind even approaching Vancouver Island. Low tracked further north than anticipated

GFS model forecast 72 hours out last September indicating a potentially damaging wind even approaching Vancouver Island. Low tracked further north than anticipated

What are the deterministic models saying for next week? A potent low is plausible somewhere in the Eastern Pacific with a possible garden variety wind-storm with the typical track curving north to Haida Gwaii, but it'll be something I'll be watching model run-to- run. 

Cheers!

#50ShadesofVan