T&T: Between the Cracks of WX Forecasting

[Mike Maurice]

I was explaining the in and outs of analyzing the national weather 
service to a friend when he jumped on my comment about the conference 
call that occurs just before the forecasts are produced every 6 hours. 
It had not occurred to him that such a thing was used in the process of 
creating the forecasts and I had overlooked the fact that it was not 
obvious.

The weather service is a bureaucracy and the process of creating the 
forecasts is not an abstract process, in that there are issues of "turf" 
(territory) and hierarchy involved. If that is not plain enough, here it 
is. There are 6 district units on the US West coast that produce the 
forecasts. Each district is divided into zones for which the forecasts 
are prepared. Generally us mariners are only interested in the marine 
forecasts which are divided into a zone from the beach to 20 miles, 
another from 20-60 and another larger one beyond 60 out to 250 miles. 
The high seas forecast and the 60-250 mile ones are generated by the 
main national office back east. These strips are further divided into 
sections of about 100 miles from north to south.

An individual office is generally responsible for about about 200 miles 
of coastline, running north to south. It should be obvious that an 
individual office can reconcile their forecasts for the boundaries at 
each of their zones and strips. This process of creating a forecast and 
having a it be realistic and logical near the boundaries of each of 
these zones and strips is not entirely rational. But at least within one 
office where maybe one or 2 people actually reconcile the discrepancies, 
the irrationality may be pretty well under control.

Now, here is where the rub comes in. Suppose the forecast on one side of 
a boundary is for 50 knots of wind and just below the boundary the 
forecast is for 10 knots. If the boundary is handled by one office this 
will be reconciled by one or two people. But, if it involves a boundary 
handled by another office, the minds involved will conduct a conference 
call to argue out a resolution. Because the boundaries are arbitrary and 
laid in stone, it is not always easy to resolve the disagreement. The 
more experienced the personnel involved, the more likely they will come 
up with a modified forecast that will appear to be logical. This process 
may not, but usually does result in an improved accuracy of the forecast.

Mariners rarely consider the forecast for the beach towns, since that's 
for landlubbers, but this is a mistake. The boundary at the shoreline is 
an arbitrary one and the weather knows very little about it. In fact you 
will often notice that the beach forecast is often quite different than 
the one for the forecast out to 20 miles. You can take advantage of this 
arbitrary boundary. I do all the time and just recently I snuck up the 
beach, near shore from Yaquina Bay to Columbia River relying on the 
beach forecast, which was for calm, rather than the rougher one forecast 
out to 20 miles. The beach forecast was right and we had a calm ride.

During the 10 hours that it took to cover the 100 odd miles involved, I 
monitored the buoy and beach town reports for wind speeds and barometer 
readings, every hour; using the VHF weather channels. I also had my 
barometer in my Garmin GPS 76S recording and we were constantly watching 
for any sign that a strong wind would develop from any direction, but 
mostly from offshore or ahead of us.

Due to the light construction of the boat involved, if the wind had come 
up we would have had to head for cover at best speed. As it was 
everything stayed calm and we put a hundred miles behind us and it got 
us within striking distance of Seattle and the spare parts we needed for 
one of the engines. Stopping short would have added immensely to the 
difficulty to getting the parts on a weekend.

In summary, you can do your own forecasting to improve on the accuracy 
of what will happen, and your best opportunities lie near the boundaries 
of the weather service's zones.

Regards,
Mike

_____________________________________
Capt. Mike Maurice
Beaverton Oregon(Near Portland)