Thunderstorm Risk YVR, plus *GASP* long range warmup?!?

Upper level low (torugh) moves inland today by thursday evening, which will provide ample lift for scattered thunderstorms is PM

Upper level low (torugh) moves inland today by thursday evening, which will provide ample lift for scattered thunderstorms is PM

Okay folks, today is going quite decent at the possible of an isolated thunderstorm for the inner South Coast today.

A moderate forcing is in place, thanks to a fairly organized upper level low pressure system moves inland today, which you can clearly see at the 500 mb height in the atmosphere).

Although I don't think daytime heating will play a significant role, surface heating could provide that extra little trigger to spark off thunderstorms on eastern Vancouver Island, the North Shore, and eastern portion of the Fraser Valley. It's likely the Puget Sound Convergence Zone (PSCZ) will set up today as well south of the border.

The relatively warm southwesterly flow will provide some moisture and temperature advection, and the NWS notes there's been a significant increase in precipitable Water content in the atmosphere.


Let's take a look at a couple stability parameters for this afternoon.

First, CAPE (convective available potential energy) 

Maximum CAPE values will fall between 21Z-3Z (2pm-8pm PST) Shear will also peak at around 15 knots (30 km/hr) for this PM

Maximum CAPE values will fall between 21Z-3Z (2pm-8pm PST) Shear will also peak at around 15 knots (30 km/hr) for this PM

But what about the Lifted Index for this afternoon? Currently SPC puts a calibrated risk of seeing a -2 LI (normally associated with thunderstorms). Between 0 and (-2) means thunderstorms are possible, especially with an added lifting mechanism (orographic, daytime heating etc.) 

Calibrated thunderstorm risk put out by the SPC:

  • I agree with this numbers with an approximate 30 % risk of a thunderstorm for Greater Vancouver, with up to 40-50% risk for central and northern Vancouver Island with a calibrated severe thunderstorm risk at 2-3% for northern Vancouver (Hardly worth a mention, to be honest)

The Long Ranger

  • Some ensemble support for a return to normal/above normal temperatures for the 7-10 day forecast
  • GEFS (Ensemble forecast) showing a return to a flattened ridge by early next week. Temps at YVR low to mid 20's are becoming more likely.

Send in your thunderstorm reports/photos/tweets if something materializes today!

 

#50shadesofVan