Days like this happen a lot more often when you have good weather information.
In my last few posts on weather I have been writing about various aspects of weather analysis. In the next three posts I’m going to pull it all together by detailing the daily procedure that we found worked well during our Arctic cruise this summer. In part one I’m going to cover weather fax, part two GRIBs, and in part three, an easy way to copy voice forecasts.
I’m going to focus on tools that work when offshore or in remote places where the internet is not available and I have provided a resources section at the end of the post.
We Still Like Weather Fax
Despite the availability of GRIBs, I’m still a great believer in regularly getting large area maps via weather fax to get an overall feel for the weather patterns.
Favourites
My favourite weather faxes are broadcast from Boston, although I also like the ones out of the UK that cover a larger area to the north and east.
Out of Boston, I get the surface analysis and 24, 48, and 96 hour forecasts as well as the 500 mb upper level analysis and 24, 48, and 96 hour forecasts.
I also get the 72 hour tropical cyclone danger area forecast to make sure I know about any tropical nasties that may be forming. I even get this forecast when we are in the north well away from the normal route of hurricanes since it may give me early warning of a system that is going to go extra-tropical in our area.
If we are using the UK products (I rarely bother with both), I will get the surface analysis and 24, 48, 72, 96, and 120 hour forecasts. One of the nice things about these charts is that they include the 500 mb information. The downside is that this makes them a little cluttered so I find them easier to read if I print them out and highlight the 564 contour as shown above.
Weather Faxes I Don’t Bother With
I don’t get any of the wind or wave products from either source since I find that GRIBs are a better way to get down to that level of detail.
As a new permanent resident of Canada, I hate to say this, but I don’t find that any of the Canadian weather fax stations add any value to the two above.
Hardware and Software
We use a PC running the excellent Weather Fax 2000 software connected to an Icom IC M700Pro single sideband radio through a demodulator (provided with the software) and a noise isolating filter.
By the way, you will get much better reception by paying for a hardware demodulator rather than just interfacing the radio to the PC through the sound card.
If you have no other need for a SSB radio, you can get these maps using any receiver that will tune in a single side band signal (many will not, so check before you buy). Note that whatever receiver you use, the key to success is a good antenna. We use our back stay which is fitted with insulators and tuned via our Icom tuner.
Tips
Both of my favourite weather fax stations broadcast on several frequencies. However, I generally find that frequencies in the 8 to 9 megahertz band seem to work best just about anywhere in the North Atlantic, although reception does vary from very good to non-existent, depending on the time of day.
I just experiment for a few days before I really need the data and don’t worry about getting all scientific about working out the best frequency and time of day using propagation tables or programs.
Since our computer is also our main navigation system and therefore up and running 24/7, I don’t bother using any of the scheduling features of Weather Fax 2000. Instead I just leave the software running on “Auto Continuous” and pick out the products I want while deleting the rest from the reception folder, using Window Picture Viewer or Microsoft Office Picture Manager (I prefer the latter) to view them as a slide show.
If you don’t want to take the power hit of leaving a radio receiver and computer running, you will need to remember to turn them on at the right time. Weather Fax 2000 does have a schedule feature to put the software in receive mode when you are expecting a particular product, but I have never found it worth the trouble, particularly since the broadcast times of the useful products are generally clustered together making the “Auto Continuous” feature a better bet.
In Weather Fax 2000 I set the “Controls” on the “Reception Properties” menu to “Detect Stop Tone”. This feature does not always work, particularly if the reception is poor, but even if two or more products end up in one file or the left margin is in the wrong place, it’s an easy matter to fix using the image tools. I also mess around with the “Skew” setting until the charts are relatively straight. Other than that, I find that the default settings work well.
With the above noted exception, I don’t generally print out weather faxes but rather clean them up using the tools in Weather Fax 2000 and then place the resulting files in a separate folder labelled with the day of the week in forecast time sequence.
Analysis
I find that stepping through the charts as a slide show, using the above mentioned viewers, on the screen makes the movement and development of systems easy to see.
I’m particularly interested in the development and movement of fronts, which don’t show on GRIBs—yes, you can guess their position from precipitation but not as well as on a weather map. When looking at fronts I really focus in on occluded ones since they can be the start of a secondary low that can sometimes be more intense than the parent.
On the upper level 500 mb reports, I’m focusing on the position of the 564 contour, the so called storm track, and I get particularly interested if I see a deep trough, or worse still, a cut off low, heading our way. And if none of that means anything to you, you will benefit hugely from buying the book recommended in this post.
Do you use weather fax? And if so do you have any tips that I have not covered? Or maybe you have a better way? Please leave a comment.
Resources
Tips and Techniques
Hardware and Software
Weather Fax Sources
Chris October 28, 2011 at 8:55 am
John,
When off soundings, I convert the faxes to charts in our chartplotting software (this also takes care of skew). This allows instant geo refererence and facilitates planning.
John November 4, 2011 at 10:35 am
Hi Chris,
Great idea, how do you actually do the conversion?
Having said that, I find that I just use weather fax charts for the general overview. To look at the situation in more detail, I find that GRIBs work better for me, and they are automatically geo-referenced and can be loaded into our navigation system.
Jim Patek (S/V Let's Go!) November 1, 2011 at 4:46 pm
John
Sorry it has taken so long to respond and thank you for the detailed explanation that will help me get more out of my WF 2000 and demodulator (by the way, can you recommend a”hardware” demodulator and does this allow the signal to come through without blasting over the SSB speaker?).
Anyway, I wanted to check out an alternative that I have been using to make sure I could get the same result. I have been using weather@mailasail.com small TIF weather charts accessed via the sat phone. The size of the small TIF is nominally around 17 kb so to do what you do slideshowing a series might be a bit expensive at $1.75 or so a chart. But, when the WF is giving a poor or non-existent report, its a very good way to go and 100% reliable.
John November 4, 2011 at 10:31 am
Hi Jim,
The hardware demodulator comes with the Weatherfax 2000 software. I don’t know of a demodulator that is sold without associated weatherfax software. Further I’m fairly sure that such a set up would not work since the software needs to be written to use a demodulator.
And no, the demodulator will not prevent the signal blasting over the speaker. Our Icom M-700 has a switch that allows us to turn off the speaker. I was under the impression that all SSB radios were so fitted. I guess not.
Good point on getting the same charts over the sat phone when reception is poor. We have done the same from time to time, although, as you say, it gets pricy.
Jim Patek (S/V Let's Go!) November 4, 2011 at 11:36 am
Hi John
Thank you for clarifying that the hardware demodulator is not an extra piece of kit. I already have it in that case. As for the switch…well, after eight years, I am still pulling that manual out on the ICOM M802 so I am not going to say that there is no switch. If I find it I will REALLY have something to thank you for.
John November 4, 2011 at 11:48 am
Hi Jim,
Just to clarify. There are two versions of Weather Fax 2000, one with the hardware demodulator, and one that uses the computer’s own sound card for demodulation.
The former is a lot better, but more expensive.
Richard Hudson November 24, 2011 at 5:02 pm
Hi John,
Great post and great series.
Are the UK weather faxes receivable from western Greenland? I was there last summer and, not realizing UK weather faxes covered areas farther north than Boston ones and assuming transmissions from UK would not make it over the mountains, never tried.
I found the Arctic Surface Analysis broadcast from Iqaluit to be quite useful, since it was the only weatherfax I knew of then that covered areas farther north than the ones from Boston. Not an easy fax to read (much data, all fine lines), but it does show all the weather systems in the Arctic.
Richard
John November 26, 2011 at 9:51 am
Hi Richard,
Yes, the UK weather faxes are easily receivable from western Greenland, on the 8 MHz band, although it does depend on the time of day. The mountains would have no affect on this since with HF radio we are dealing with signal bounce from the ionosphere. Smart radio people who are into that kind of thing can calculate the optimal time and frequency for HF radio reception, but I have to confess that I belong to the dumb “try it and see” crowd.