Nuri's Fury: A ticking time bomb

Wednesday, November 5, 2014, 1:42 PM - After the drenching rains of October, some relative tranquility is just around the corner, Vancouver.

But, first a recap of a significant rain event earlier this week. A subtropical plume of moisture was aimed at the South Coast like a fire hose; consequently, flooding became an issue by Monday evening.

But was this event predictable? During my briefing shift Thursday evening, I encouraged Kim Macdonald to send a tweet. With some hesitation, Kim sent out this:

This is exciting as synoptic scale weather events are beginning to become predictable 5-7 days in advance with long range pattern recognition and temperature trends predictable up to two weeks.

Take a look below at the 24 hour rainfall prediction by the WRF-GFS for 24 hour rainfall totals. Any shaded area in black could realistically expect localized flooding as those amounts are in excess of 60 mm.

Note the Olympic Rain shadow in the upper left hand corner, and heavier rains over the Olympic mountains. These fluctuations are primarily driven by topography

Recently, the coach of the New England Patroits, Bill Belichick made some controversial statements about weather forecast accuracy. But were his comments merited?

Operational forecast skill has seen significant improvement over the past several decades. These aren't your grandmother's forecasts from the 1960's. In fact, a three-day forecast in 2014 is about as accurate as a one-day forecast from the late early 1980s.

Nuri's Fury

Super Typhoon Nuri will undergo a slow weakening process and a transition to an extra-tropical cyclon is a lock as the sytem begins to recurve towards the Bering Sea.

The atmospheric dynamics will be extremely favourable for the system to rapidly intensify and 'bomb out' as Nuri enters the right rear entrance of an extremely powerful jet streaks

For simplicity, think of a jet streak as jet fuel for a weather system, or a region that promotes the development of cyclogenesis (the birth of a low pressure system). The jet streak modeled below is an incredible 215 knots or 400 km/hr. Don't worry, you'd likely to be able to stand up during those winds as the air is very thin at those altitudes. Jet streaks also mould the troughs and ridges in the atmosphere and help shape the Rossby Waves that circle the globe, and can often amplify a jet stream to become more meriodional. In 6-10 days, cooler air will filter into Eastern Canada, thanks in part by the influence of typhoon Nuri and the associated powerful jet streak that will amplify the downstream pattern

Ear-popping pressure drop

Often when meteorologists measure storms a 1 bergeron drop in pressure (24mb) in 24 hours indicates a very significant intensification process. Ex-Nuri is about to attempt 2X this.

Typhoon Nuri is forecasted to undergo an astounding 57 mb pressure drop in 24 short hours or well over 2 bergerons

Gigantic Waves

As seen below, the American Wave model (WW3) has consistently predicted wave heights in excess of 50 feet (or 15 metres) over the past several runs. That's significant wave height or roughly the 1/3 largest waves one might encounter at sea. It's entirely possibly that one may encounter a wave roughly 2x the significant wave height, or in this case over 100 feet or 30 metres

TC Nuri could evolve into the strongest extratropical cyclone on record for the northern Pacific ocean in 4 days. But, will this be a record low pressure for the region (Alaska)? I believe if there is a chance to break a record, it will be for Alaska's lowest recorded pressure, which is a mere 927 mb, recorded in 1977 in Dutch Harbor.

There's some debate, but several sources indicate that this system will at the very least make a run at one of the strongest storms this region of Earth has ever seen, and at the very least a top 5 since records have been kept.

NEXT PAGE: WHAT DOES THIS ALL MEAN FOR VANCOUVER?