It Snowed Again

My friend Ray took this photo of 100 Prince Street this morning. As you can see, it snowed again. For almost 24 hours.

The key thing to notice in the photo, though, is that the first 2 or 3 feet of the front roof are all but completely cleaned of snow, the result of roof raking every couple of hours on Sunday. Fortunately, the wind took care of the back roof rather effectively, so I needed to spend far less time there than the last time around.

The photo is deceptive: our house isn’t actually blocked in by snow, as there’s a partially-cleared sidewalk between the two snowbanks.

But there’s still a lot of snow.

Snow on 100 Prince St.

Retirement of the Fish Points

Hidden away in an obscure circular that appears to have been released in early 2014 by Gander Control is notice that a group of waypoints know as the “fish points” are to be deleted:

Fish Points

I’ve been puzzling over how aeronautical navigation waypoints get their names; it would appear, if this retirement of the “fish points” is a guide, that that are simply made up, using some sort of arbitrary theme, while ensuring that they don’t sound like other waypoint names, something reinforced in this Nav Canada circular on the same topic that reads, in part “New names to de-conflict with other similar sounding fixes on the NAT” (NAT being “North Atlantic Tracks”).

The challenge now is to connect the waypoint codes with their associated fish species. Some, like SCROD, and OYSTR and CARPE are obvious. Others, I have no idea.



So I’ve become slightly obsessed with with the world of flight planning and trans-oceanic air travel: it’s a new puzzle to solve, and it involves things flying over my house on the way to far-off lands. What’s not to love?

Last night around midnight, Aer Lingus Flight № 138 (code named EIN138), flying from Boston to Dublin, Ireland, flew over eastern PEI, making landfall near Point Prim, crossing south-eastern Kings County, continuing over Georgetown and Souris and heading off to sea. Here’s its track, from

EIN138 over PEI

Looking up flight EIN138 in FlightAware provides a lot of interesting information about the flight, including a section labeled “Route” in a box on the right:

EIN138 Flight Plan

The route information is a series of “waypoints” – aeronautical bread crumbs, if you will – that EIN138 was to follow as it made its way from Boston to Dublin:


There is, oddly, no comprehensive database of these waypoints: there was a public resource called DAFIF, but it went dark in 2006, apparently amidst copyright concerns from Australia.

But there remain some web-based, if not open, data sources, that offer an incomplete way of looking up these waypoint codes, the most slick of which is You can simply paste the waypoints from FlightAware into Skyvector and it will, to the best of its ability, “connect the dots” (of the waypoints it knows about) and show you the flight plan on a map: in use

What’s most interesting, for my Prince Edward Island-focused purposes here, are two of those waypoints, ALLEX and ELSIR.

Zooming in a, I can see the ALLEX is a waypoint at N44°25.00’, W67°.00.00’:


In decimal, that’s 44.416667, -67, which is a spot just inside Canadian airspace off Grand Manan, New Brunswick.

ELSIR, on the other hand, is at N49°30.09’, W52°0.17, or 49.5025, -52.004722 decimal, which is a spot in the North Atlantic off the east coast of Newfoundland:


ELSIR is an interesting waypoint because it’s one of the official “aeronautical doorways” to flying across the North Atlantic: all airplanes flying across the ocean fly along prescribed North Atlantic Tracks, which change daily: last night, our Aer Lingus flight started its trans-oceanic voyage by passing over ELSIR.

Running between ALLEX and ELSIR is a line that happens to be labeled N209C (which also appears in the flight plan in FlightAware):


And N209C, because it connects ALLEX and ELSIR, runs directly over eastern Prince Edward Island:


All of which means, I’m assuming, that if you see ALLEX N209C ELSIR in a flight plan, it means that the plane in question will be flying over eastern Prince Edward Island.

Meanwhile, Aer Lingus Flight № 138 landed safely in Dublin at 7:16 a.m. this morning.

18 Hours of Overflights

I’ve been detecting and archiving ADS-B position reports from airplanes flying over Prince Edward Island for the last 18 hours; here’s a map of what my little Raspberry Pi has picked up:

That’s a simple visualization of the positions recorded created using To allow me to see individual planes’ tracks, I dumped the data points into a CSV file, edited it, and then ran it through GPS Visualizer:

Flights over PEI

There were 1,095 position reports received from 37 distinct flights (here’s the raw data should you wish to experiment with it yourself):

  • AAL42
  • AAL50
  • AAL78
  • AAL80
  • AAL86
  • ACA848
  • ACA878
  • AWE722
  • AWE750
  • AZA610
  • AZA65F
  • BAW196
  • BAW81V
  • CJT621
  • DAL24
  • DAL72
  • DLH425
  • DLH431
  • DLH435
  • EIN104
  • EIN138
  • ETD150
  • FDX36
  • ICE630
  • KLM18
  • N800J
  • NAX7012
  • QTR764
  • QTR8102
  • SAS926
  • SWR52
  • THY18A
  • UAL114
  • UAL126
  • UAL58
  • VIR12E
  • WJA424

You can enter those flight numbers into Google, or into FlightAware, and see the flight details: when you do this you’ll notice that the vast majority of the flights were flying above 30,000 feet and were heading to or from Europe: none of the local flights from Charlottetown Airport were detected, likely because the ADS-B receiver I’m using is on the windowsill over my office downtown, and doesn’t have line-of-sight to local flight paths.

My next step, thus, is to put an antenna up on the roof.

A Good Day for Wind Energy on PEI

When I talk to people about wind energy generation on Prince Edward Island, they are often under the impression that the wind is a relatively small part of the energy mix on the Island.

And there’s no doubt that because of its variability sometimes there is no wind energy generation on the Island. Like when the wind isn’t blowing. And that’s one of the significant challenges of wind’s contribution to the Island’s energy future.

That all said, sometimes there are days, like yesterday, when the contribute of wind energy is near or above 100% of the provincial load for most of the day.

On this chart, showing 24 hours of load and generation starting at 3:00 a.m. on March 11 and ending on 3:00 a.m. on March 12, the orange line represents wind energy generation in megawatts and the blue line the province’s load in megawatts (the load being “how much electricity we’re all using together”). The wind topped the load several times during the day, including the four and a half hours from 9:30 p.m. to 2:00 a.m.

PEI Wind Energy vs. Load, March 11, 2015