Heatwaves, humidity, and a brush with lightning

My apologies for a lack of writing the past few weeks. We've entered the summer, dry season where Vancouver can brag on being one of the driest major Canadian cities from May until early October. 

Compared to the historical heat wave of 2009, offshore gradients are not as extreme hindering true record breaking temperatures along the coast.

In the summer of 2009 Temperatures in YVR and many communities reached their all-time high temperatures with YVR reading an astounding 35C with Humidex values in the lower 40's for the Fraser Valley -- truly exceptional.

500 MB reanalysis for the historic heat wave in July 2009. Strong offshore gradients, since air flows from high to low pressure

500 MB reanalysis for the historic heat wave in July 2009. Strong offshore gradients, since air flows from high to low pressure

Our current ridge is nothing to sneeze at. Very pronounced height anomaly for this type of year, with a significant cut-off upper low in eastern Canada. 

The temperature contrasts become extremely apparent with neighbouring provinces experiencing vastly different weather conditions.

Sunday is currently forecasted to be one of the warmest days during the next week for #YVR... with high pressure and subsidence dominating the west. 

The 2M temperature departures from normal (+15C in BC and -15C in Southern Manitoba) are truly impressive. The jet stream is extremely meridional and typically correlates well with severe weather (Take note storm chasers).

Thunderstorm Potential

  • Couple thunderstorm ingredients are coming together for a possible southern BC thunderstorm event. Not too impressed with low level moisture, but a decent jet streak in southern Washington State and Oregon may be enough to initiate thunderstorms 

  • LI (Lifted Index) reaches nearly -10 on the crest of the cascades. LI's in this geographical region typically don't reach double digits. 

  • For now, greatest risk of a storm is eastern Fraser Valley, but at this point I can't rule out a thunderstorm for inland Vancouver Island and the Lower Mainland. 

#50ShadesofVan