Blocking Highs, Love ’em Or Hate ’em

The way to detect and understand blocking highs is to look at the 500 mb predictions and particularly the 5640 mb line (bold on graphic above).

As I write, the North Atlantic is a weather hot-mess with hurricanes and gales dotted all over the map, and yet all the models are predicting an incredible run of settled early fall weather and light winds for Nova Scotia, extending out ten days or more.

What’s going on?

We in Nova Scotia are falling under the protection of the weather-godfather of upper level systems: a blocking high.

I’m loving it, since I can go rowing on quite cool mornings and sailing in the afternoon when the sea breeze kicks in on our loverly Mahone Bay.

But if we are trying to make a passage under sail in the midlatitudes we will hate a blocker for it’s light winds. And if we are to the west of one in the northern mid-latitudes it’s likely we will hate the stationary low pressure over us that’s blocked from moving away.

In either case we can use this understanding to make better strategic decisions than we ever will from just looking at a surface model.

I was about to start decommissioning our boat for winter layup, but have delayed that, and back in the day I used this information to make our cruises more comfortable and safer.

That said, I have radically oversimplified, as is fitting for a tip, but if you want to understand how manage your voyages strategically, rather than just looking at models with no understanding, we have an Online Book for that:

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Q & A: Iridium Go! or Go Exec


The new Predict Wind Iridium Go Exec device does indeed have a subscription plan that limits data according to how much one pays, i.e: $159.95/month buys you only 50MB of data. That includes all data transfer including tracking data.

Do you happen to have a clue how much data you found that you used, on the average, per month with the original Iridium Go device?

I am just trying to figure out what size plan would be needed in order to not have to worry about constantly hitting the ceiling towards the end of the month. I believe you & I would have similar usage (that is forecasts & basic emails).


The exact amount of data we used varied a lot, so I don’t think that’s the way to make the decision.

Rather, what I can say is that we never had a problem getting all the weather information I needed, and I download a lot more than most people, as well as being able to handle all of our email, which, again, is a heavier load than most people, because of running AAC.

Sure, sometimes the GO! took as much as an hour to deal with all that, but so what? With good software you don’t need to sit around and watch it, and if there’s a drop-out it reconnects automatically and continues on until done.

So if it were me, I would stick with GO! to get the unlimited plan, given that I just don’t want the stress and aggravation of worrying about a hard data limit and the huge charges if that gets inadvertently breached.

I also would not want to have to figure out how to buy more data if I ran out while at sea.

So given that GO Exec is not fast enough to surf the internet, and does not have an unlimited data plan, I just don’t see the point of it against the original GO! with an unlimited plan.

That said, as I have said before, being able to make calls without the kluge of a connected smart phone is a nice upgrade, but not enough to push me into Exec. Rather I would recommend buying a secondhand Iridium handset for the emergency call function.

More on exactly how to use G0! For both strategic and tactical weather forecasting.


New Iridium Go! exec

Predict Wind have a preliminary announcement video for a new faster version of the Iridium GO!.

Not a lot of details yet, but it’s supposedly a lot faster, although not fast enough to use for actual internet surfing.

The big drawback will be if the unlimited data package available with the original GO! is not offered with this new unit or is a lot more expensive.

I’m guessing it might not be the great deal that the unlimited plan on the original unit is since the new GO! uses the Certus modem like Iridium Pro.

If no unlimited plan is offered, or a much more expensive one, I’m thinking that for many users who are just looking to download email and weather information at sea the original GO! may still be the best option since I have never had any problems getting all the weather data and email I need over the older unit.

Definitely the key thing to look into and clearly understand before purchasing one of these new units is the availability and cost of an unlimited plan.

One upgrade I did like is that the new unit has a speaker and microphone and so can be used for telephone calls without connecting a smartphone. This is a big safety benefit since there have been incidents with the old GO! where users were not able to get voice communications working quickly in an emergency.

Here’s the intro video, not that it’s much use:

And here’s a Q&A that might be more useful.