Juan-A-Be

Earth Wind Map: Animation link here Just another storm? 1000hpa wind speed forecast for Wednesday afternoon, with sustained category 1 hurricane winds off Nova Scotia

Earth Wind Map: Animation link here

Just another storm? 1000hpa wind speed forecast for Wednesday afternoon, with sustained category 1 hurricane winds off Nova Scotia

Although the title of this post is a bit of a joke and a play on words referencing Hurricane Juan, this storm is no laughing matter for the Canadian Maritimes. 

I've seen several comments on social media shrugging this system off as 'just another nor'easter'.

Sure, Atlantic Canada gets 1-2 significant systems that 'bomb' or go through a process called bombogenesis, where the low pressure 'bombs out' and falls more than 24mb in 24 hours.

Several models have this system approaching double that (or nearly 50 mb in 24 hours). 

What makes this system unique?

1. Triple Phased System

Photo by Plymouth State Weather Center (H/T Nick P.)

Photo by Plymouth State Weather Center (H/T Nick P.)

  • Triple phasing was prominent in other prolific storms such as the Storm of the Century in 1993
  • For all these pieces of energy to align in the atmosphere and phase at the correct timing adds to the rarity of the event -- why they occur on average every 10+ years
    • You need the Polar jet, Arctic Jet, and Sub-Tropical Jet to all play a role. One of these pieces missing and it significantly hinders the strength of these systems
  • BC, do you feel guilty?

2. Amount of CAA (Cold Air Advection)

  • The models are having trouble finding a three week period at the end of March with such cold temperatures as far south as they are progged -- Error, out of range.

Sea Ice Threat

  • 100 km/hr+ winds along with plenty of sea ice could wreak havoc along some of the exposed shores, especially with that strong NE wind increasing on Wednesday AM. 

Storm Surge Potential

ESTOPS latest storm Surge Model (By NOAA) 

ESTOPS latest storm Surge Model (By NOAA) 

Significant Wave Height

Def: This is the average of the highest one-third (33%) of waves (measured from trough to crest) that occur in a given period. This is measured because the larger waves are usually more significant than the smaller wave

Source

  • The maximum significant wave height of 51 feet (or over 15 metres), is EXTREMELY impressive, but there will be higher waves. 
  • Maximum wave possible could be expected to be nearly 100 feet or 30+ metre seas
Wave Watch 3 Model 18Z, image by Weather Bell

Wave Watch 3 Model 18Z, image by Weather Bell

Projected Snowfall

Fresh off the press, model output from the 00Z GFS 72 hour snowfall accumulations using standard 10:1 ratio. Units unfortunately in inches, not CM. Sorry Atlantic Canada.

Fresh off the press, model output from the 00Z GFS 72 hour snowfall accumulations using standard 10:1 ratio. Units unfortunately in inches, not CM. Sorry Atlantic Canada.

  • Maximum model output at 10:1 ratio (25.9 inches or 66 cm)
  • Heaviest swath N and W of Halifax, left of the track of the low pressure system
    • Watcn for extremely heavy amounts of snow on PEI as well.

Please head all watches and warnings issued by Environment Canada, follow extensive coverage by The Weather Network, and stay safe. 

This storm has the very real potential to be life threatening, so take this storm seriously.

Tomorrow would be an excellent day to stock up on supplies, charge electronic supplies and prepare for an extended power outage. 

Stay Safe.

#50ShadesofVan