long-term forecasts

longjohnsadler

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ParaHandy

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i've been pulling 7 day forecasts off the NOAA model for some time.

Now suppose on the 12 April we left Bermuda for Azores. There's a dominant low moving NE slowly up the East coast of US. The predicted wind 800m on the 19 April from Bermuda would be:
on 12 April (7 day fc) 20kn SSW with the low 987mb 521m at 23degrees from Bermuda
on 13 April (6 day fc) 30n SSW 987mb 942m at 42
on 14 April (5 day fc) 25kn SW 987mb 723m at 31
on 15 April (4 day fc) 25kn WSW 987mb 546m at 32
on 16 April (3 day fc) 25kn WSW 986mb 593m at 31
on 17 April (2 day fc) 20kn SW 986mb 486m at 30
on 18 April (next day fc) 15kn SSW 986mb 470m at 22
on 19 April (actual) 25kn SSW 985mb 498m at 29

Make of that what you will. The 6 & 7 day forecasts had the centre of the low 200 to 400m out of position but all others were close enough. The least accurate wind speed forecast was the next day forecast but the high to the south shifted a bit and that put on a few knots.

Contrast this with previous month when the North Atlantic was very unsettled and forecasts seemed not to be worth the paper they were written on. A very deep low passed over Newfoundland at the beginning of April with hurricane force winds and I hope that's the last we see of them ...

Of course, as soon as we put to sea, it'll all go crap again .. sod's law
 
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