LIVE UPDATES: #BCSTORM March Madness Edition

Hot off the press! Latest RGEM is still leading the way with heavy snow amounts (probably overdone!). The CDN models performed fairly well last weekend, so I'm putting a little more faith in them as of late. Accumulation shown in inches

Hot off the press! Latest RGEM is still leading the way with heavy snow amounts (probably overdone!). The CDN models performed fairly well last weekend, so I'm putting a little more faith in them as of late. Accumulation shown in inches

Environment Canada has issued numerous weather warnings for the following #BCstorm with significant accumulation expected along portions of the South Coast.

I also did a detailed post about this upcoming event which you can find by scrolling down the page, or clicking here.

This post in particular will highlight some of the changing conditions, snowfall accumulations, and other noteworthy data I stumble across. 

If you have any questions at all, send them my way OR comment at the bottom of this post.

Love your input, everyone.

Don't forget tag your social media posts with #BCstorm to get the attention of meteorologists. Any observational data or information about adverse weather conditions can be valuable. 


UPDATE: 930AM : 

  • Reports of rain already mixing with the light snow in Cloverdale 
  • Radar shows this current heavier band of precipitation moving east, leaving us dry, momentarily. 
    • ill it be cold enough to start up again as snow? 
      • es, depending on location (Abbotsford is a safe bet for all day snow)
  • So, if you want all day snow, drive out to the valley, except don't. Conditions out there will be horrendous with low visibility, possible freezing rain, and heavy snow
Future atmospheric sounding for YVR, showing warming lower levels on the atmosphere. Note: Very light outflow winds with the freezing level around 500 metres, enough for a cold rain by this afternoon Highlighted the 0 degree isotherm in yellow. In a future post, I'll go into more depth on how to read the Skew T plots, one of the most important tools in the forecaster's arsenal. 

Future atmospheric sounding for YVR, showing warming lower levels on the atmosphere. Note: Very light outflow winds with the freezing level around 500 metres, enough for a cold rain by this afternoon Highlighted the 0 degree isotherm in yellow. In a future post, I'll go into more depth on how to read the Skew T plots, one of the most important tools in the forecaster's arsenal. 


UPDATE: 820 AM

Heaviest snow remains out in the Valley (Abbotsford), according to latest radar returns this morning

Heaviest snow remains out in the Valley (Abbotsford), according to latest radar returns this morning

  • Environment Canada Maintains snowfall warnings for east Vancouver Island and the Lower Mainland (5-10cm)
  • Most locations around the South Coast are reporting light snow at this hour
  • Lots of locations from Campbell River to the higher elevations of Victoria have observed snow this morning as well.

Upper Air Temp Estimation: 

700 mb: -10C

850 MB: -3.5C

925 mb: -1C

**Pretty marginal for snow, but cool easterly winds are helping maintain lower freezing levels than would suggest by these numbers. 

Surface wet bulb temps remain right around the freezing mark for Metro Vancouver, so we'll have to keep an eye on that. 

When will this change to rain?

I'll get back to you. 


UPDATE: 9:45 PM

Current webcam on eastern Vancouver Island showing snow beginning to fall this evening 

Current webcam on eastern Vancouver Island showing snow beginning to fall this evening 

  • Snow has been observed falling on Vancouver Island (Ladysmith, Nanaimo over the past couple of hours), including to our south in Bellingham

 

  • Can current radar give us any indication when to expect to see a few flakes around the Lower Mainland?
    • Currently, the precipitation is too light, and the atmosphere too dry for the snow to make it to the surface of the lower mainland right now...but this will change

 

  • New report that snow has started to fall in Cumberland, BC

If you want a tweet featured in the blog, just tag @50shadesofVan in a tweet, and I'll be sure to read it, eventually.

Radar display as of 930, showing locations south of delta probably reporting light snow flurries at this hour close to the USA border

Radar display as of 930, showing locations south of delta probably reporting light snow flurries at this hour close to the USA border

I have to emphasize this is no means an easy forecast to nail down. In fact, it's damn near impossible.

As of 4PM, if I were in Environment Canada's shoes I also would've issued a snowfall warning after analysing the guidance available at the time. It was the logical thing to do, following the precautionary principle.  

In the world of social media, dealing with potential forecast busts and alterations, Conveying these dynamic forecasts and situations to the public can be an extremely difficult task and something meteorologists are working on figuring out. 

People tend to focus on the higher number in the range (10 to 25 cm put out by Environment Canada), without reading the fine print. 

I believe very few, if any of us will see 25 cm fall over the next 24 hours, unless you're at a favourable elevation, away from a body of water, and heavier precipitation bands develop in your location for a sustained period tomorrow.

Current Upper Air Temps (Estimations):

925 mb: -1.5C

850 mb: -3.5C 

*Still acceptable for surface snowfall


UPDATE: 7:40 PM

  • Approximate snow/rain line setting up, using the wet bulb 0 isotherm as a boundary in yellow
  • YVR reporting a temp of .8C with a dew point of -4. There's little doubt this event will begin as snow for all around the South Coast
    • And, just as I type this YVR begins to observe light snow at 7:31PST maintaining low dew point of -4C
Surface wet bulb map (NOAA). Victoria is on the cusp, and YYJ is reporting rain at the hour (possible freezing rain in area)

Surface wet bulb map (NOAA). Victoria is on the cusp, and YYJ is reporting rain at the hour (possible freezing rain in area)